Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie More good information - thanks for posting. Good work on finding the alternate core. I have a couple of questions:

    1. By “trigger board”, are you referring to the TPL5010 discussed above?  (Adafruit carries the TPL5110, I think.)    Is the idea here to power and de-power the radio, or mcu, to discover the rock-bottom minimum current requirement?
      
    2. What are you sacrificing when not using the external crystal? And to do this, are you setting fuses to tell the 328 to use the internal crystal? I've found setting fuses to be a complicated affair.

    Good questions!

    1. Yes, by "trigger board", the adafruit tpl5110, or something like it, is what I have in mind. The goal would be zero leakage current beyond the ~40 nanoamps of management overhead. I don't know if the p-channel mosfet design in adafruit's tpl5110 breakout board achieves zero leakage (or near enough),but it would be worth measuring. I think Kevin Darrah may be the one who coined the term "trigBoard". His design is a lot more elaborate and, I assume, costly: https://www.kevindarrah.com/wiki/index.php?title=TrigBoardV7

    Is the idea here to power and de-power the radio, or mcu, to discover the rock-bottom minimum current requirement?

    Yes. It's a little more complicated though, because generally the mcu/radio wake-up time is much longer from a cold start than from a deep sleep, so the real objective would be to find the breakeven point at which power-off is the better choice (i.e. how long does the duty cycle need to be).

    What are you sacrificing when not using the external crystal?

    Accuracy. If you were interfacing to something that had extremely tight timing requirements, the crystal would be more accurate. In practice, I haven't ever noticed a difference in anything that I've done.

    And to do this, are you setting fuses to tell the 328 to use the internal crystal? I've found setting fuses to be a complicated affair.

    Yes, I set the fuses. Currently I use the following fuse settings:
    atmega328p_fuse_settings.png
    By running from the 8Mhz internal oscillator and sleeping, not only can you sleep the atmega328p at just 100na, but as a bonus the atmega328p can wake up in just 3 microseconds (I previously measured it with an oscilloscope, so that number is solid). For being such an old mcu, the atmega328p can be amazingly high performance when it comes to saving power. This becomes of greater relevance if you're getting your power by harvesting weak energy sources.

    If you want to play around with setting fuse bits, the standard advice is to leave the Extended bits alone until you know what you're doing. Even then, there's probably no need to change them. It's the High and Low bits that are of relevance.

    A great source of information is: https://www.gammon.com.au/power



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    sleep the atmega328p at just 100na

    Wow, that is pretty close to zero in my view. Consider battery self-discharge in comparison: I use 18650 LiOn batteries in most of my projects. Say a 2000 mAh battery loses 1%/month in self discharge s(ome say it is much higher). Well, the math, if I did it right, shows a self-discharge of about 25 uA. So sleeping at 100nA is really impressive.

    Thanks for the fuse guidance. I will employ this next chance I get.


  • Hero Member

    @Larson Yes. The RFM69 can also be slept at just 100na, so taken together they are an awesome duo. If you're running from 2xAA batteries, then the the combined 200na are essentially zero. If, in contrast, you're trying to harvest energy from a small solar cell in an indoor environment that's dimly lit by LED lighting only rarely, then it becomes more relevant.

    Anyhow, I've noticed that a lot of people measure very small currents incorrectly, so just trying to find answers on the internet, which is full of wrong measurements, isn't easy. Datasheets can provide some insight.



  • @NeverDie Yes, the experience and knowledge found by doing (measuring) is always deeper,

    Forgot to mention: Kevin Darah. I have bought several of his TrigBoards. I find the price to be a good value for the design, components, assembly, and all the content he has posted. The quality of his boards is great. I am a Patreon of his. I just need to play with the TrigBoards some more.


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie Yes, the experience and knowledge found by doing (measuring) is always deeper,

    Forgot to mention: Kevin Darah. I have bought several of his TrigBoards. I find the price to be a good value for the design, components, assembly, and all the content he has posted. The quality of his boards is great. I am a Patreon of his. I just need to play with the TrigBoards some more.

    I'd be interested to hear your thoughts on Kevin's trigBoards after you've had a chance to get familiar with them. A compare/contrast of his board to the adafruit board would be even more awesome. The adafruit board is a very simple design and would cost less than $1 in parts if you were to source them yourself. I suppose its main limitation is 1. the maximum sleep time is two hours, and 2. not as accurate as a proper RTC. In its favor is that at 40na the sleep current consumption is next to nothing. On the other hand, some RTCs have a sleep current less than 1ua, so maybe that's good enough.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    In its favor is that at 40na the sleep current...

    I'll order several. Then compare to the TrigBoards. Adafruit's TPL5011 advertises a run current of 20uA. Is that acceptable for you? If so I'll buy several. Couple of limitations for me: 1. Time - I'm about a month out, 2. My Ammeter is a standard DMM from Harbor Freight. The smallest range is 200uA and I've found it very useful. Certainly fine enough to show the 20uA, but inadequate for nanoAmps.


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    In its favor is that at 40na the sleep current...

    I'll order several. Then compare to the TrigBoards. Adafruit's TPL5011 advertises a run current of 20uA. Is that acceptable for you? If so I'll buy several. Couple of limitations for me: 1. Time - I'm about a month out, 2. My Ammeter is a standard DMM from Harbor Freight. The smallest range is 200uA and I've found it very useful. Certainly fine enough to show the 20uA, but inadequate for nanoAmps.

    Hmmmm... Something's wrong then with Adafruit's design if it's 20uA. The chip itself consumes only 35na according to its datasheet:
    https://www.ti.com/lit/ds/symlink/tpl5110.pdf?ts=1652658923819&ref_url=https%3A%2F%2Fwww.google.com%2F
    Maybe their p-channel mosfet has high leakage current with the circuit has they've designed it? I would pass if it really is 20uA. I'm sure I could do better than that.

    You need something like either a Current Ranger or a MicroCurrent Gold to accurately measure microamps and nanoamps. Cost is around $100.

    Also, I just now looked at one of Kevin Darrah's videos:
    PART 3 Cellular -The Ultimate DIY Home Security System - ESP8266 (trigBoard) + 4G LTE Modem – 22:37
    — Kevin Darrah

    where he has embraced ESP-NOW. He said his esp8266 still takes around 1.5 seconds to wake up and transmit, even though running ESP-NOW, which is a very long time, as the module will be burning current through out that wake-up interval. In the example he showed, the delay was quite noticeable (though definitely an improvement compared to before when he was using plain wi-fi). Of course, the devil is in the details, but seeing that I'm more skeptical now than before.



  • @NeverDie I recognized the KD image as soon as I saw it. I'll watch... again... after dinner. Yes, the battery economics depend on time and power as you say. One of the tricks I have learned is aggregating data at the MCU level in RTC memory. I'm using both a 328 and an ESP; each dedicated to it's task. When 20 samples (minutes of data) are gathered the MCU wakes the ESP so it can bulk-load data to Thingspeak. This economizes the cost of the ESP wake-up by a factor of 20. This is all for my water-meter monitoring project. It has been fun stuff and I've learned a bunch. And I'm not using ESP-NOW because I'm going directly from the ESP transmitter to my home network - so I could do even better if I injected an ESP repeater that would transmit to the network. I think my wake-up/network-connection is about 8 seconds.

    We have strayed far away from your initial "anyone-useing..." post. I hope that is okay?


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    We have strayed far away from your initial "anyone-useing..." post. I hope that is okay?

    Yes, it's fine. I'll be testing the E28-2G4M27S once more after my JLCPCB's arrive.


  • Hero Member

    The PCB's arived today, about 1 week after I placed the order. I already put together one mote:
    v1.JPG
    It nicely fits the footprint of two AA batteries. I'll be running some tests soon and hopefully getting definitive answers.

    By the way, the flashing green LED is being driven by Arduino Pin 20. 😄


  • Hero Member

    Mea Culpa. I found a mistake in my original setup which may explain at least some of the poor performance. I had thought that both my usb-to-serial converters were operating at 3.3v, but I noticed during disassembly that one was operating at 5v instead. Even though I was using pro mini's with 3.3v LDO's on them, it turns out that the 3.3v LDO only functions when the voltage is being fed to the pro mini over the RAW pin (which is never in my setup). Instead, the usb-to-serial converter fed its 5v directly to VCC over the header pin, and from there directly to the radio module. Although I did later do experiments where the entire setup was being run off of 3v of battery only, it may be that the radio module was already damaged by then.

    I wouldn't be surprised if others besides just me have fallen into this same trap, as it might be natural to assume that a "3.3v pro mini" regulates all of its voltage sources to be 3.3v. However, such is not the case, as confirmed by checking the schematic.

    So, to remove all doubt, I'll use brand new radio modules when testing with this new test setup, which won't be using pro mini's at all this time around. It turns out my barebones atmega328p design works just fine, and this way I have total control over the quality of all the components going into it, including X7R on all the capacitors (whereas who knows exactly what quality of components are used on pro mini's).


  • Hero Member

    Here's an end-view of the test platform:
    end_view.JPG
    As you can see, I wouldn't want the batteries to be any closer together than they already are, or they would likely short out between them. As it stands, they're firmly in place, so no worries for now. These kinds of placement tolerance issues are hard to vet in advance prior to building a prototype. The keystone datasheet gave no guidance at all on side by side positioning. If I were to do it over, I think I'd give it another millimeter or two of safety factor separation.

    Of bigger concern is the switch placement. A side mounted switch might be too tight a fit because of the battery connectors. On the other hand, the existing vertical switch can potentially can get in the way of things, so I may try mounting it upside down on the battery side. This would make it less accessible than it currently is, but, at the same time, it wouldn't get bumped by accident either. I reckon that with the aid of an insulated paperclip, or maybe a chop-stick, it should be possible to turn it on-off even in the more cramped position. Probably a more correct solution would be a surface mounted side-switch that's tiny but somehow good enough to carry 600ma+ currents. Finding such a thing may take some searching though, assuming it exists at all.

    In a perfect world, the radio module, if it were to use its trace antenna, would be hanging over the end of the base PCB below. Part of the reason it wasn't was out of concern as to whether the breakout board might collide with the switch. Well, with the new switch position, that won't be a worry, so if I create a new version of the breakout board for the radio module, I'd make it so that the radio module has its trace antenna hang out over the end of not just the breakout adapter, but the end of the test platform as well.

    I normally use regular headers, but out of an interest in making the whole thing more compact, and for snugger connections, I made a last minute decision to use machine pin headers instead. This was after the board had already been fab'd to use regular headers. If I were to do it over, I would have bigger diameter through-holes drilled into the PCB in order to seat the machine pin female headers properly. I'll do that in the next version I get fab'd, assuming there is a next version.

    At the opposite end there's space to add a pico-blade for the FTDI attachment. If that works, then in a future design there will be space for extending a few more pins out from the MCU, making for a more complete universal test platform. For present testing purposes, though, things are good enough as they are.

    If anyone reading this has any further thoughts or suggestions, please feel free to jump in and post them. I find it's less fun to do everything single handedly.


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    In its favor is that at 40na the sleep current...

    I'll order several. Then compare to the TrigBoards. Adafruit's TPL5011 advertises a run current of 20uA. Is that acceptable for you? If so I'll buy several. Couple of limitations for me: 1. Time - I'm about a month out, 2. My Ammeter is a standard DMM from Harbor Freight. The smallest range is 200uA and I've found it very useful. Certainly fine enough to show the 20uA, but inadequate for nanoAmps.

    I don't see any uCurrent Gold's for sale at the moment, but I did find a clone of it, which has what looks like a nice improvement over the original: you can plug it directly into an oscilloscope via its BNC connector.
    alt text
    https://www.n-fuse.co/devices/tinyCurrent-precision-low-Current-Measurement-Shunt-and-Amplifier-Device.html
    or
    https://github.com/nfhw/tinycurrent
    as it is open source.

    I temporarily misplaced my Dave Jones uCurrent Gold that I bought from him directly during his Kickstarter campaign. However, if I can't locate it soon, I may be either buying or making one of these tinyCurrent's to take advantage of the built-in BNC connector.


  • Hero Member

    Reporting back: Problem solved!

    Using two of the new test nodes, one in transmit and the other in receive, and each using a brand new E28-2G4M27S with just the trace antenna only, and with the default library settings for each, and with the transmit node in a different room with two closed doors in-between (exactly as before, with the initial testing at the start of this thread), I'm now getting the kind of flawless communication that I had expected all along from LoRa on the 2.4Ghz band:

    
    12:23:12 May 18 2022
    V1.0
    
    104_LoRa_Receiver_Detailed_Setup Starting
    
    LoRa Device found
    
    SX1280,PACKET_TYPE_LORA,2444999936hz,SF7,BW406250,CR4:5
    SX1280,PACKET_TYPE_LORA,Preamble_12,Explicit,PayloadL_255,CRC_ON,IQ_NORMAL,LNAgain_HighSensitivity
    
    Reg    0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
    0x900  80 FF 77 41 20 FA BC 13 C1 80 00 00 00 00 00 61 
    0x910  9C 44 00 00 00 19 00 00 00 19 87 65 43 21 7F FF 
    0x920  FF FF FF 00 70 37 12 50 D0 80 00 C0 5F D2 8F 0A 
    0x930  00 C0 00 00 00 24 00 21 28 B0 30 0D 01 51 63 0C 
    0x940  58 0B 32 0A 16 24 6B 96 00 18 00 00 00 00 00 00 
    0x950  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x960  00 00 00 00 00 00 00 00 00 00 FF FF FF FF FF FF 
    0x970  FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 04 
    0x980  00 0B 18 70 00 00 00 4C 00 F0 64 00 00 00 00 00 
    0x990  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9A0  00 08 EC B8 9D 8A E6 66 04 00 00 00 00 00 00 00 
    0x9B0  00 08 EC B8 9D 8A E6 66 04 00 00 00 00 00 00 00 
    0x9C0  00 16 00 3F E8 01 FF FF FF FF 5E 4D 25 10 55 55 
    0x9D0  55 55 55 55 55 55 55 55 55 55 55 55 55 00 00 00 
    0x9E0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9F0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    
    
    Receiver ready - RXBUFFER_SIZE 32
    
    5s  Hello World 1234567890*,CRC,DAAB,RSSI,-54dBm,SNR,10dB,Length,23,Packets,1,Errors,0,IRQreg,8012
    9s  Hello World 1234567890*,CRC,DAAB,RSSI,-55dBm,SNR,14dB,Length,23,Packets,2,Errors,0,IRQreg,8012
    13s  Hello World 1234567890*,CRC,DAAB,RSSI,-55dBm,SNR,10dB,Length,23,Packets,3,Errors,0,IRQreg,8012
    18s  Hello World 1234567890*,CRC,DAAB,RSSI,-58dBm,SNR,13dB,Length,23,Packets,4,Errors,0,IRQreg,8012
    22s  Hello World 1234567890*,CRC,DAAB,RSSI,-56dBm,SNR,14dB,Length,23,Packets,5,Errors,0,IRQreg,8012
    26s  Hello World 1234567890*,CRC,DAAB,RSSI,-52dBm,SNR,13dB,Length,23,Packets,6,Errors,0,IRQreg,8012
    30s  Hello World 1234567890*,CRC,DAAB,RSSI,-53dBm,SNR,9dB,Length,23,Packets,7,Errors,0,IRQreg,8012
    34s  Hello World 1234567890*,CRC,DAAB,RSSI,-51dBm,SNR,8dB,Length,23,Packets,8,Errors,0,IRQreg,8012
    38s  Hello World 1234567890*,CRC,DAAB,RSSI,-54dBm,SNR,13dB,Length,23,Packets,9,Errors,0,IRQreg,8012
    42s  Hello World 1234567890*,CRC,DAAB,RSSI,-52dBm,SNR,14dB,Length,23,Packets,10,Errors,0,IRQreg,8012
    46s  Hello World 1234567890*,CRC,DAAB,RSSI,-55dBm,SNR,13dB,Length,23,Packets,11,Errors,0,IRQreg,8012
    50s  Hello World 1234567890*,CRC,DAAB,RSSI,-55dBm,SNR,12dB,Length,23,Packets,12,Errors,0,IRQreg,8012
    54s  Hello World 1234567890*,CRC,DAAB,RSSI,-56dBm,SNR,9dB,Length,23,Packets,13,Errors,0,IRQreg,8012
    58s  Hello World 1234567890*,CRC,DAAB,RSSI,-59dBm,SNR,9dB,Length,23,Packets,14,Errors,0,IRQreg,8012
    62s  Hello World 1234567890*,CRC,DAAB,RSSI,-59dBm,SNR,13dB,Length,23,Packets,15,Errors,0,IRQreg,8012
    66s  Hello World 1234567890*,CRC,DAAB,RSSI,-61dBm,SNR,13dB,Length,23,Packets,16,Errors,0,IRQreg,8012
    70s  Hello World 1234567890*,CRC,DAAB,RSSI,-57dBm,SNR,13dB,Length,23,Packets,17,Errors,0,IRQreg,8012
    75s  Hello World 1234567890*,CRC,DAAB,RSSI,-54dBm,SNR,14dB,Length,23,Packets,18,Errors,0,IRQreg,8012
    79s  Hello World 1234567890*,CRC,DAAB,RSSI,-55dBm,SNR,14dB,Length,23,Packets,19,Errors,0,IRQreg,8012
    83s  Hello World 1234567890*,CRC,DAAB,RSSI,-54dBm,SNR,13dB,Length,23,Packets,20,Errors,0,IRQreg,8012
    
    

    Notice that now both the RSSI is very good and the SNR is very high as compared to when I was having trouble with the earlier setup.

    The E28-2G4M27S is vindicated. Case closed! 😃


  • Hero Member

    Epilog: I hooked up the old receiver, with its external antenna, to the new mote, and it's not obviously worse for the wear:

    
    12:23:12 May 18 2022
    V1.0
    
    104_LoRa_Receiver_Detailed_Setup Starting
    
    LoRa Device found
    
    SX1280,PACKET_TYPE_LORA,2444999936hz,SF7,BW406250,CR4:5
    SX1280,PACKET_TYPE_LORA,Preamble_12,Explicit,PayloadL_255,CRC_ON,IQ_NORMAL,LNAgain_HighSensitivity
    
    Reg    0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
    0x900  80 FF 77 41 20 FA BC 13 C1 80 00 00 00 00 00 61 
    0x910  9C 44 00 00 00 19 00 00 00 19 87 65 43 21 7F FF 
    0x920  FF FF FF 00 70 37 12 50 D0 80 00 C0 5F D2 8F 0A 
    0x930  00 C0 00 00 00 24 00 21 28 B0 30 0D 01 51 63 0C 
    0x940  58 0B 32 0A 16 24 6B 96 00 18 00 00 00 00 00 00 
    0x950  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x960  00 00 00 00 00 00 00 00 00 00 FF FF FF FF FF FF 
    0x970  FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF 04 
    0x980  00 0B 18 70 00 00 00 4C 00 F0 64 00 00 00 00 00 
    0x990  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9A0  00 08 EC B8 9D 8A E6 66 04 00 00 00 00 00 00 00 
    0x9B0  00 08 EC B8 9D 8A E6 66 04 00 00 00 00 00 00 00 
    0x9C0  00 16 00 3F E8 01 FF FF FF FF 5E 4D 25 10 55 55 
    0x9D0  55 55 55 55 55 55 55 55 55 55 55 55 55 00 00 00 
    0x9E0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9F0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    
    
    Receiver ready - RXBUFFER_SIZE 32
    
    4s  Hello World 1234567890*,CRC,DAAB,RSSI,-57dBm,SNR,12dB,Length,23,Packets,1,Errors,0,IRQreg,8012
    8s  Hello World 1234567890*,CRC,DAAB,RSSI,-55dBm,SNR,13dB,Length,23,Packets,2,Errors,0,IRQreg,8012
    12s  Hello World 1234567890*,CRC,DAAB,RSSI,-57dBm,SNR,13dB,Length,23,Packets,3,Errors,0,IRQreg,8012
    16s  Hello World 1234567890*,CRC,DAAB,RSSI,-57dBm,SNR,12dB,Length,23,Packets,4,Errors,0,IRQreg,8012
    20s  Hello World 1234567890*,CRC,DAAB,RSSI,-54dBm,SNR,9dB,Length,23,Packets,5,Errors,0,IRQreg,8012
    24s  Hello World 1234567890*,CRC,DAAB,RSSI,-52dBm,SNR,3dB,Length,23,Packets,6,Errors,0,IRQreg,8012
    29s  Hello World 1234567890*,CRC,DAAB,RSSI,-55dBm,SNR,11dB,Length,23,Packets,7,Errors,0,IRQreg,8012
    33s  Hello World 1234567890*,CRC,DAAB,RSSI,-55dBm,SNR,13dB,Length,23,Packets,8,Errors,0,IRQreg,8012
    37s  Hello World 1234567890*,CRC,DAAB,RSSI,-50dBm,SNR,12dB,Length,23,Packets,9,Errors,0,IRQreg,8012
    41s  Hello World 1234567890*,CRC,DAAB,RSSI,-53dBm,SNR,13dB,Length,23,Packets,10,Errors,0,IRQreg,8012
    45s  Hello World 1234567890*,CRC,DAAB,RSSI,-56dBm,SNR,14dB,Length,23,Packets,11,Errors,0,IRQreg,8012
    49s  Hello World 1234567890*,CRC,DAAB,RSSI,-53dBm,SNR,8dB,Length,23,Packets,12,Errors,0,IRQreg,8012
    53s  Hello World 1234567890*,CRC,DAAB,RSSI,-51dBm,SNR,3dB,Length,23,Packets,13,Errors,0,IRQreg,8012
    57s  Hello World 1234567890*,CRC,DAAB,RSSI,-52dBm,SNR,8dB,Length,23,Packets,14,Errors,0,IRQreg,8012
    61s  Hello World 1234567890*,CRC,DAAB,RSSI,-52dBm,SNR,12dB,Length,23,Packets,15,Errors,0,IRQreg,8012
    65s  Hello World 1234567890*,CRC,DAAB,RSSI,-52dBm,SNR,11dB,Length,23,Packets,16,Errors,0,IRQreg,8012
    69s  Hello World 1234567890*,CRC,DAAB,RSSI,-52dBm,SNR,13dB,Length,23,Packets,17,Errors,0,IRQreg,8012
    73s  Hello World 1234567890*,CRC,DAAB,RSSI,-50dBm,SNR,13dB,Length,23,Packets,18,Errors,0,IRQreg,8012
    77s  Hello World 1234567890*,CRC,DAAB,RSSI,-51dBm,SNR,13dB,Length,23,Packets,19,Errors,0,IRQreg,8012
    82s  Hello World 1234567890*,CRC,DAAB,RSSI,-55dBm,SNR,12dB,Length,23,Packets,20,Errors,0,IRQreg,8012
    86s  Hello World 1234567890*,CRC,DAAB,RSSI,-56dBm,SNR,7dB,Length,23,Packets,21,Errors,0,IRQreg,8012
    90s  Hello World 1234567890*,CRC,DAAB,RSSI,-57dBm,SNR,13dB,Length,23,Packets,22,Errors,0,IRQreg,8012
    94s  Hello World 1234567890*,CRC,DAAB,RSSI,-56dBm,SNR,13dB,Length,23,Packets,23,Errors,0,IRQreg,8012
    98s  Hello World 1234567890*,CRC,DAAB,RSSI,-48dBm,SNR,6dB,Length,23,Packets,24,Errors,0,IRQreg,8012
    
    

    One thing I do notice,though, when reviewing the receive packet data, with both the new and old radios are considerable variances in SNR. The 915Mhz adafruit transceivers don't show much variance (see earlier post for the telemetry). I presume, therefore, the larger SNR variances are caused by environmental interference that varies over time in the 2.4Ghz band, or at least the default channel in that band chosen by the library.

    The end! 😄


  • Hero Member

    Putting a Yagi antenna on this, one could perhaps gather data pointing to where the interference sources are located by backing out the "noise" value from the RSSI and SNR data collected.


  • Hero Member

    One last thing to try: to eliminate the possibility that the USB-to-FTDI might be introducing noise into the receiver, I think I'll try a test setup with three motes. Two will be completely battery powered with no external connection, and one will be connected to the computer for datalogging over USB. The main change is that the receive node will receive packets, as before, from the battery powered transmitter mote, but instead of directly feeding those results over USB to the computer, it will transmit those results (including the RSSI and SNR on the packets it received) to the third mote. The third mote will be located in the same room as the receiver mote, and it is the third mote that will be connected to the computer over USB. The third mote being in the same room as the receive mote guarantees it won't lose any packets, and if any noise is introduced over USB to the third mote, it will be irrelevant, because the primary receiver mote will be stand-alone and entirely battery operated, with no possibility of USB injecting noise into it.

    I suspect it won't make any difference to the final results, but the only way to know for sure is to test it. Going forward, to eliminate all doubt, I'll use the same type of three mote setup when testing other radios also. When testing different radios, all I'll need to do is swap in new radio shields and re-program the bases.

    Anyhow, this thread has turned out to be more of a blog than anything, but, as always, it becomes more interesting if other people post too so that it's not just me recording a monolog. I'll start a new thread when I start testing other radios, with the goal being to compare the performance of different radio modules to see whether any one module stands out as obviously "best" in the general sense, or at least better understand under which use-cases which radio module would be better than the alternatives.


  • Hero Member

    I haven't yet set up the 3 mote testing structure that I outlined above, but, for comparison, using the same two mote system for testing 915Mhz Dorji modules (each with a 3.25" wire whip antenna), with the same transmit and receive locations, the results there were rock solid SNR values with no variance over the sample:

    
    12:16:09 May 20 2022
    V1.1
    
    104_LoRa_Receiver_Detailed_Setup Starting
    
    LoRa Device found
    
    SX1262,434000000hz,SF7,BW125000,CR4:5,LDRO_Off,SyncWord_0x1424,IQNormal,Preamble_8
    SX1262,PacketMode_LoRa,Explicit,LNAgain_Boosted
    
    Reg    0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
    0x800  00 00 00 00 29 07 20 09 00 10 19 D4 10 C9 10 00 
    0x810  10 C7 0F FE 10 C7 0F FE 00 76 8A A9 4A 00 00 00 
    0x820  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x830  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x840  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x850  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x860  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x870  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x880  03 00 00 5F 10 08 00 00 08 04 00 1B 20 00 00 0C 
    0x890  00 00 00 10 BD 0F 0A 07 10 00 26 01 01 53 06 07 
    0x8A0  10 00 AD 20 5A 04 F0 02 56 56 54 43 96 20 40 00 
    0x8B0  00 83 11 00 01 04 0A 4C 14 0A 2F 01 6B FF FF 00 
    0x8C0  00 A0 20 00 00 00 AC 00 1C 00 00 AB 05 30 11 14 
    0x8D0  0C 15 16 40 06 00 00 10 E8 00 00 00 00 09 31 39 
    0x8E0  90 39 0C 04 40 20 16 38 06 00 05 04 03 02 01 01 
    0x8F0  03 00 00 00 30 00 00 00 00 00 00 00 00 00 00 00 
    0x900  30 00 00 00 00 64 00 00 00 00 00 00 24 04 47 04 
    0x910  00 2F 00 00 00 03 0A 00 15 35 09 00 02 2A 67 08 
    0x920  07 04 05 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x930  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x940  00 07 00 03 02 00 10 00 0A 00 03 04 00 14 0C 00 
    0x950  00 00 00 06 00 00 00 00 00 00 00 00 00 00 00 00 
    0x960  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x970  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x980  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x990  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9A0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9B0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9C0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9D0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9E0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9F0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    
    
    Receiver ready - RXBUFFER_SIZE 32
    
    4s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,1,Errors,0,IRQreg,16
    5s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,2,Errors,0,IRQreg,16
    6s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,3,Errors,0,IRQreg,16
    7s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,4,Errors,0,IRQreg,16
    8s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,5,Errors,0,IRQreg,16
    9s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,6,Errors,0,IRQreg,16
    10s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,7,Errors,0,IRQreg,16
    12s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,8,Errors,0,IRQreg,16
    13s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,9,Errors,0,IRQreg,16
    14s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,10,Errors,0,IRQreg,16
    15s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,11,Errors,0,IRQreg,16
    16s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,12,Errors,0,IRQreg,16
    17s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,13,Errors,0,IRQreg,16
    18s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,14,Errors,0,IRQreg,16
    19s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,15,Errors,0,IRQreg,16
    20s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,16,Errors,0,IRQreg,16
    21s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,17,Errors,0,IRQreg,16
    23s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,18,Errors,0,IRQreg,16
    24s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,19,Errors,0,IRQreg,16
    25s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,20,Errors,0,IRQreg,16
    26s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,21,Errors,0,IRQreg,16
    27s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,22,Errors,0,IRQreg,16
    28s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,23,Errors,0,IRQreg,16
    29s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,24,Errors,0,IRQreg,16
    30s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,25,Errors,0,IRQreg,16
    31s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,26,Errors,0,IRQreg,16
    32s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,27,Errors,0,IRQreg,16
    34s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,28,Errors,0,IRQreg,16
    35s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,29,Errors,0,IRQreg,16
    36s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,30,Errors,0,IRQreg,16
    37s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,31,Errors,0,IRQreg,16
    38s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,32,Errors,0,IRQreg,16
    39s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,33,Errors,0,IRQreg,16
    40s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,34,Errors,0,IRQreg,16
    41s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,35,Errors,0,IRQreg,16
    42s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,36,Errors,0,IRQreg,16
    43s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,37,Errors,0,IRQreg,16
    45s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,38,Errors,0,IRQreg,16
    46s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,39,Errors,0,IRQreg,16
    47s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,40,Errors,0,IRQreg,16
    48s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,12dB,Length,23,Packets,41,Errors,0,IRQreg,16
    49s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,42,Errors,0,IRQreg,16
    50s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,43,Errors,0,IRQreg,16
    51s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,44,Errors,0,IRQreg,16
    52s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,45,Errors,0,IRQreg,16
    53s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,46,Errors,0,IRQreg,16
    55s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,47,Errors,0,IRQreg,16
    56s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,48,Errors,0,IRQreg,16
    57s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,49,Errors,0,IRQreg,16
    58s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,50,Errors,0,IRQreg,16
    59s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,51,Errors,0,IRQreg,16
    60s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,52,Errors,0,IRQreg,16
    61s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,53,Errors,0,IRQreg,16
    62s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,54,Errors,0,IRQreg,16
    63s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,55,Errors,0,IRQreg,16
    64s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,56,Errors,0,IRQreg,16
    66s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,57,Errors,0,IRQreg,16
    67s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,58,Errors,0,IRQreg,16
    68s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,59,Errors,0,IRQreg,16
    69s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,60,Errors,0,IRQreg,16
    70s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,61,Errors,0,IRQreg,16
    71s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,62,Errors,0,IRQreg,16
    72s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,63,Errors,0,IRQreg,16
    73s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,64,Errors,0,IRQreg,16
    74s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,65,Errors,0,IRQreg,16
    75s  Hello World 1234567890*,CRC,DAAB,RSSI,-94dBm,SNR,11dB,Length,23,Packets,66,Errors,0,IRQreg,16
    77s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,67,Errors,0,IRQreg,16
    78s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,68,Errors,0,IRQreg,16
    79s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,69,Errors,0,IRQreg,16
    80s  Hello World 1234567890*,CRC,DAAB,RSSI,-93dBm,SNR,11dB,Length,23,Packets,70,Errors,0,IRQreg,16
    

    This was with the Dorji set to its maximum transmit power of 22dB, as compared to the E28-2G4M27S, which has the advantage of an even higher 27dB transmit power.

    [Edit: oops. Reviewing the output, I see that the library defaulted to 434Mhz! So, these results were great even with the wrong length antenna installed for 434Mhz. I'll try again at the proper frequency. 😊 ]


  • Hero Member

    OK, here it is corrected for 915Mhz, as it should have been the first time:

    
    12:34:34 May 20 2022
    V1.1
    
    104_LoRa_Receiver_Detailed_Setup Starting
    
    LoRa Device found
    
    SX1262,915000000hz,SF7,BW125000,CR4:5,LDRO_Off,SyncWord_0x1424,IQNormal,Preamble_8
    SX1262,PacketMode_LoRa,Explicit,LNAgain_Boosted
    
    Reg    0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
    0x800  00 00 00 00 29 07 20 09 00 10 19 D4 10 4E 10 13 
    0x810  10 4B 10 1E 10 4B 10 1E 00 DA AA E6 DB 00 00 00 
    0x820  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x830  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x840  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x850  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x860  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x870  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x880  03 00 00 5F 10 08 00 00 08 04 00 39 30 00 00 0C 
    0x890  00 00 00 10 BD 0F 0A 07 10 00 26 01 01 53 06 07 
    0x8A0  10 00 AD 20 5A 04 F0 02 56 56 54 43 96 20 40 00 
    0x8B0  00 83 11 00 01 04 0A 4C 14 0A 2F 01 6B FF FF 00 
    0x8C0  00 A0 20 00 00 00 AC 00 1C 00 00 AB 05 30 12 13 
    0x8D0  0C 15 16 40 06 00 00 10 E8 00 00 00 00 00 39 39 
    0x8E0  90 39 0C 04 40 20 16 38 06 00 05 04 03 02 01 01 
    0x8F0  03 00 00 00 30 00 00 00 00 00 00 00 00 00 00 00 
    0x900  30 00 00 00 00 64 00 00 00 00 00 00 24 04 47 04 
    0x910  00 2F 00 00 00 03 0A 00 15 35 09 00 02 29 67 08 
    0x920  07 04 05 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x930  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x940  00 07 00 03 02 00 10 00 0A 00 03 04 00 14 0C 00 
    0x950  00 00 00 06 00 00 00 00 00 00 00 00 00 00 00 00 
    0x960  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x970  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x980  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x990  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9A0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9B0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9C0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9D0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9E0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    0x9F0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
    
    
    Receiver ready - RXBUFFER_SIZE 32
    
    4s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,1,Errors,0,IRQreg,16
    5s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,2,Errors,0,IRQreg,16
    6s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,3,Errors,0,IRQreg,16
    7s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,4,Errors,0,IRQreg,16
    8s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,5,Errors,0,IRQreg,16
    9s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,6,Errors,0,IRQreg,16
    11s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,7,Errors,0,IRQreg,16
    12s  Hello World 1234567890*,CRC,DAAB,RSSI,-44dBm,SNR,12dB,Length,23,Packets,8,Errors,0,IRQreg,16
    13s  Hello World 1234567890*,CRC,DAAB,RSSI,-44dBm,SNR,12dB,Length,23,Packets,9,Errors,0,IRQreg,16
    14s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,10,Errors,0,IRQreg,16
    15s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,11,Errors,0,IRQreg,16
    16s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,12,Errors,0,IRQreg,16
    17s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,13,Errors,0,IRQreg,16
    18s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,14,Errors,0,IRQreg,16
    19s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,15,Errors,0,IRQreg,16
    21s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,16,Errors,0,IRQreg,16
    22s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,17,Errors,0,IRQreg,16
    23s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,18,Errors,0,IRQreg,16
    24s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,19,Errors,0,IRQreg,16
    25s  Hello World 1234567890*,CRC,DAAB,RSSI,-44dBm,SNR,11dB,Length,23,Packets,20,Errors,0,IRQreg,16
    26s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,21,Errors,0,IRQreg,16
    27s  Hello World 1234567890*,CRC,DAAB,RSSI,-44dBm,SNR,11dB,Length,23,Packets,22,Errors,0,IRQreg,16
    28s  Hello World 1234567890*,CRC,DAAB,RSSI,-44dBm,SNR,12dB,Length,23,Packets,23,Errors,0,IRQreg,16
    29s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,24,Errors,0,IRQreg,16
    30s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,25,Errors,0,IRQreg,16
    32s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,26,Errors,0,IRQreg,16
    33s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,27,Errors,0,IRQreg,16
    34s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,28,Errors,0,IRQreg,16
    35s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,29,Errors,0,IRQreg,16
    36s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,30,Errors,0,IRQreg,16
    37s  Hello World 1234567890*,CRC,DAAB,RSSI,-44dBm,SNR,11dB,Length,23,Packets,31,Errors,0,IRQreg,16
    38s  Hello World 1234567890*,CRC,DAAB,RSSI,-44dBm,SNR,12dB,Length,23,Packets,32,Errors,0,IRQreg,16
    39s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,33,Errors,0,IRQreg,16
    40s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,34,Errors,0,IRQreg,16
    41s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,35,Errors,0,IRQreg,16
    43s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,36,Errors,0,IRQreg,16
    44s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,37,Errors,0,IRQreg,16
    45s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,38,Errors,0,IRQreg,16
    46s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,39,Errors,0,IRQreg,16
    47s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,40,Errors,0,IRQreg,16
    48s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,41,Errors,0,IRQreg,16
    49s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,42,Errors,0,IRQreg,16
    50s  Hello World 1234567890*,CRC,DAAB,RSSI,-44dBm,SNR,12dB,Length,23,Packets,43,Errors,0,IRQreg,16
    51s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,44,Errors,0,IRQreg,16
    52s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,45,Errors,0,IRQreg,16
    54s  Hello World 1234567890*,CRC,DAAB,RSSI,-44dBm,SNR,11dB,Length,23,Packets,46,Errors,0,IRQreg,16
    55s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,47,Errors,0,IRQreg,16
    56s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,48,Errors,0,IRQreg,16
    57s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,49,Errors,0,IRQreg,16
    58s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,50,Errors,0,IRQreg,16
    59s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,51,Errors,0,IRQreg,16
    60s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,52,Errors,0,IRQreg,16
    61s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,53,Errors,0,IRQreg,16
    62s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,54,Errors,0,IRQreg,16
    64s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,55,Errors,0,IRQreg,16
    65s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,56,Errors,0,IRQreg,16
    66s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,57,Errors,0,IRQreg,16
    67s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,58,Errors,0,IRQreg,16
    68s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,59,Errors,0,IRQreg,16
    69s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,60,Errors,0,IRQreg,16
    70s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,61,Errors,0,IRQreg,16
    71s  Hello World 1234567890*,CRC,DAAB,RSSI,-42dBm,SNR,12dB,Length,23,Packets,62,Errors,0,IRQreg,16
    72s  Hello World 1234567890*,CRC,DAAB,RSSI,-42dBm,SNR,12dB,Length,23,Packets,63,Errors,0,IRQreg,16
    73s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,64,Errors,0,IRQreg,16
    75s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,12dB,Length,23,Packets,65,Errors,0,IRQreg,16
    76s  Hello World 1234567890*,CRC,DAAB,RSSI,-44dBm,SNR,12dB,Length,23,Packets,66,Errors,0,IRQreg,16
    77s  Hello World 1234567890*,CRC,DAAB,RSSI,-44dBm,SNR,11dB,Length,23,Packets,67,Errors,0,IRQreg,16
    78s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,68,Errors,0,IRQreg,16
    79s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,69,Errors,0,IRQreg,16
    80s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,70,Errors,0,IRQreg,16
    81s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,71,Errors,0,IRQreg,16
    82s  Hello World 1234567890*,CRC,DAAB,RSSI,-43dBm,SNR,11dB,Length,23,Packets,72,Errors,0,IRQreg,16
    83s  Hello World 1234567890*,CRC,DAAB,RSSI,-45dBm,SNR,12dB,Length,23,Packets,73,Errors,0,IRQreg,16
    84s  Hello World 1234567890*,CRC,DAAB,RSSI,-46dBm,SNR,11dB,Length,23,Packets,74,Errors,0,IRQreg,16
    

    Interestingly, even though the RSSI is vastly better, the SNR stays at around 11 to 12dB. Well, regardless, the Dorji plainly appears to perform much better in my particular home environment, at least so far, at the given frequencies and other library defaults (which do appear to be different between the SX1280 and the SX1262 (e.g. default bandwidth), so a fair comparison will need to be more equal than what's provided by only just the library defaults).

    When I'm a bit more prepared, I'll compare/contrast the two different radios performance along what I would guess is the worst possible transmission path in my house. When that time comes, I'll report the results on a new thread that will be meant for comparing the performance of different radio modules. For now this was just a preliminary test to confirm that the DORJI radio module was working at all, but the results were interesting anyway.



  • @NeverDie You Rock. That looks like a great testing platform... and tiny. In my 5-minute review I have two points to add that your post(s) solicit: 1. To protect the battery gap, as it is, how about a thin piece of cardboard? It appears that the offsets in the machine pin headers have a little room to slip a small zip-tie to restrain the cardboard so that it does not interfere with the test rig on top. It is easier to hack it than redesign, resubmit, repay and all that. 2. Love to join you on this venture so you are not single handed. I'm guilty of leaching and not teaching. I can't do it now (excuses) but hope to join you and help contribute.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    I don't see any uCurrent Gold's for sale at the moment, but I did find a clone of it, which has what looks like a nice improvement over the original: you can plug it directly into an oscilloscope via its BNC connector.

    Andreas Spiess [https://www.youtube.com/watch?v=LUB8RWzzLWc] has convinced me to buy a Power Profiler Kit II, or one that is assembled. That way I don't need to also buy a scope! I have more work to do.


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie You Rock. That looks like a great testing platform... and tiny. In my 5-minute review I have two points to add that your post(s) solicit: 1. To protect the battery gap, as it is, how about a thin piece of cardboard? It appears that the offsets in the machine pin headers have a little room to slip a small zip-tie to restrain the cardboard so that it does not interfere with the test rig on top. It is easier to hack it than redesign, resubmit, repay and all that. 2. Love to join you on this venture so you are not single handed. I'm guilty of leaching and not teaching. I can't do it now (excuses) but hope to join you and help contribute.

    By all means! The more the merrier!

    I posted some PPK2 screenshots on another thread that I recently started: https://forum.mysensors.org/topic/11954/most-reliable-best-radio

    It does a nice job of measuring milliamps. I wouldn't say the PPK2 is good at measuring <1ua currents though, such as sleep currents. If that matters to you, you'll want a Current Ranger, or TinyCurrents or similar.


  • Hero Member

    Worth mentioning is that the SX1280 includes a FLRC (Fast Long Range Communications) modem that can, in theory, go as fast as 1.3mbps. When time allows it may be worth giving it a try.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    I wouldn't say the PPK2 is good at measuring <1ua currents though, such as sleep currents. If that matters to you, you'll want a Current Ranger, or TinyCurrents or similar.

    I'd say the PPK2 is the way to go. Your other post defines the <1ua current as ... nearly infinite in human terms and battery self-discharge rates. Squeezing a stone can yield no more water. Thanks for the posts, once again.



  • @NeverDie
    For me, it is one step at a time.
    PPKII: Bought one! I'm back ordered at DigiKey and expect delivery in early June. I'll have to wait on the uCurrent or CurrentRanger until I get a scope. ... I know, the SSD screen on the CurentRanger and a bit of math would suffice. I may get there. Sounds it sound like you have already settled on the best-radio, so your test-rig may be for naught. If you need help, and the PPKII is sufficient, let me know. I am indebted to you for your work.


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie
    For me, it is one step at a time.
    PPKII: Bought one! I'm back ordered at DigiKey and expect delivery in early June. I'll have to wait on the uCurrent or CurrentRanger until I get a scope. ... I know, the SSD screen on the CurentRanger and a bit of math would suffice. I may get there. Sounds it sound like you have already settled on the best-radio, so your test-rig may be for naught. If you need help, and the PPKII is sufficient, let me know. I am indebted to you for your work.

    I haven't truly settled on anything just yet. It's a bit much for just one person to sort out, so maybe I'll take a pause until after you get your gear. It would be more fun working with somebody else than doing it all alone.



  • @NeverDie I'll keep you posted. I'm just emerging from hibernation and am 'shaking-it-off'. My main interest is regenerating my PIR home network that was 433 MHz based and am interested in your LoRa ideas/posts. Is your test rig publicly available at OSH Park? I haven’t looked lately. If so I’ll order some, or have some assembled at JLCPCB. When I do that, I'll send you my spares (my minimum order is 5 and I can't use that many.)


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie I'll keep you posted. I'm just emerging from hibernation and 'shaking-it-off'. My main interest is regenerating my PIR home network that was 433 MHz based and am interested in your LoRa ideas/posts. Is your test rig publicly available at OSH Park? I haven’t looked lately. If so I’ll order some, or have some assembled at JLCPCB. When I do that, I'll send you my spares (minimum order is 5.)

    I certainly could post it if you like. One reason I haven't already is that it is very much a version 1.0, and it doesn't seem worthy. I've thought of things I would improve about it for a much better version 2.0.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    ... very much a version 1.0, and it doesn't seem worthy.

    Your humility is profound! But I understand your reluctance as I always find problems with my boards that I later need to hack. Gotta start somewhere, right? Post it please. Next I'll order some SX1280 & 1282 boards. I've got a long way to go.


  • Hero Member

    OK, will do, but for full disclosure, some things I would do differently for version 2.0:

    1. include an ISP header
    2. make it a better fit for machine pins.
    3. Change the routing on one of the power traces so that it doesn't run under the keystone AA battery holder. I found out that solder mask isn't such a good insulator, and I've had a couple of test boards short out there. The workaround was to raise up the keystone, but it's kludgy.
    4. Separate the AA battery holders a bit more so that they don't risk shorting each other out.
    5. Widen the board a bit so that the battery holders don't risk shorting against header pins.
    6. Change the layout so that the radio modules would sit on the end, rather rather than in the center. That way, radio modules with trace antenna could hang over the end of the test setup.
    7. Some changes relating to the silkscreening to make assembly less ambiguous.
    8. Make all of the unused atmega328p pins accessible.

    I guess what I can do is post the version 1.0 boards on openhardware.io as "work in progress" and then upgrade them to version 2.0 when/if that ever happens.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    I guess what I can do is post the version 1.0 boards on openhardware.io as "work in progress" and then upgrade them to version 2.0 when/if that ever happens.

    I have gathered that openhardware.io can make the effort collaborative. That would be good for me. I've got limited skill in Eagle as that has been my schematic/board platform (plus, of course, board manufactures like OSH Park). Your 8 points are very actionable.



  • @NeverDie Wow, that was fast. I just found it. Thanks. I'm on the bus.


  • Hero Member



  • @NeverDie Thanks again. I've downloaded both and am putting together a BOM to send to DigiKey. Hopefully I'll sneek an order in with my back-ordered PPKII. I'm sure I'll have lots of questions. The Assembly plant I use allows one-side component placement. I'll have to choose one and it will probably be the sole 386p chip. I've never come close to soldering that fine of pitch. Surely it would be a mess.


  • Hero Member

    @Larson You should leave out one 0.1uF capacitor on the atmega328p test platform. If it's installed it won't work. It's the one closest to the LEDs and the picoblade. Including it in the design was an error on my part, but the platform works perfectly fine without it.

    Also you won't need the LED or resistor on the E28-2G4M27S adapter, because you'll have two LEDs to choose from on the atmega328p test platform.


  • Hero Member

    @Larson As to soldering the atmega328p, it's actually easy if you use a lot of rosin flux. Only takes a minute or two to solder by hand and it comes out great. Then clean off the excess flux with IPA. This old school flux works like magic: https://www.amazon.com/gp/product/B008ZIV85A/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1



  • @NeverDie I'll give it a go. I've added the flux to my running BOM list. I'm upgrading my alcohol too because my 70% isn't cutting it!



  • @Larson While I definitely agree about the importance of using plenty of flux - it's almost magic - another very important tool is to have plenty of desoldering braid around. It's super cheap, and along with plenty of flux it makes it easy to clean up excess solder on the board or bridging between two pins, or whatever.

    That combination will let you solder all kinds of things that otherwise look very daunting.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    As you can see, I wouldn't want the batteries to be any closer together than they already are, or they would likely short out between them. As it stands, they're firmly in place, so no worries for now. These kinds of placement tolerance issues are hard to vet in advance prior to building a prototype. The keystone datasheet gave no guidance at all on side by side positioning. If I were to do it over, I think I'd give it another millimeter or two of safety factor separation.

    Add some Kapton tape to the sides of the terminals next to each other to insulate against accidents without making it more cramped.


  • Hero Member

    I just now added schematics to the openhardware.io projects that I posted above.

    I'm trying to post the KiCAD archive, which would be ideal, but the present system extracts the .zip file and only posts a fraction of the files in the KiCAD archive. If I find some another way that works, I'll post it then.


  • Hero Member

    The SX1280 has three possible DIO pins, but, as implied by the library header file, I left two of them disconnected. In hindsight, I wouldn't recommend that. It turns out you can connect any of those DIO pins to any of 16 different SX1280 interrupts using an onchip switching fabric, which I foresee will be quite handy to, for example, rapidly know precisely when a CAD cycle completes or if anything was detected during a CAD cycle. Therefore, until version 2 of the adapter board, I may bodge DIO2 and DIO3 to some of the unused atmega328p interrupt pins as a workable stopgap measure.


  • Hero Member

    OK, I posted the KiCAD 6 archives for both the Ebyte adapter and for the Barebones atmega328p testbed. They appear as a .rar file in the project files on openhardware.io. I'm no longer a bottleneck. Anyone can open them up and pick up exactly where I left off if they want to make changes or fork.

    Inside the .rar file is a zip file. Simply import the project zip file into Kicad, and you're golden.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Also, I'm really curious as to how sensitive (or not) the ESP8266 2.4Ghz ESP-NOW communications will be to interference in a home environment that, at least so far, seems to have shredded 2.4Ghz LoRa.

    My ESP-NOW (8266) 2.4 Ghz experience has been pretty uninterrupted that I know of. For about 3 years, I've been monitoring the water pressure of my home system. The sensor/ESP transmitter is at the water heater and the receiver is remote. To give some sense of the density of my WiFi environment: my browser scan detects 7 networks and I live in a medium-density neighborhood (about 4 homes/acre), so it is not too bad. Funny, the recharge curves of the system water pressure, after use, looks just like a capacitor voltage in a RC circuit, only much slower.

    Unlike the low-power theme of this thread, my ESP’s drink as much as they need as they are always on and mains powered.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    It does a nice job of measuring milliamps. I wouldn't say the PPK2 is good at measuring <1ua currents though, such as sleep currents. If that matters to you, you'll want a Current Ranger, or TinyCurrents or similar.

    Out of gratitude I'd like to buy a TinyCurrent for you. Saw the Donate button on the openhardware.io. Does that go to you?

    The TinyCurrents device would be interesting to own. But if the granularity of the PPKII (still on backorder) is down to 1uA, then anything more exceeds my practical interest. For my hypothetical 2000mAhr battery, a burn rate of 1uA would last 228 years... again, if I did the math right. That exceeds my interest, though it is fun to chase down the details.

    Been re-reading this thread for days. I want to help and hope to, if I can keep up with the blog entries. I've got a shopping list running - some of it already ordered!


  • Hero Member

    @Larson That's very generous of you, but by no means feel obligated. The TinyCurrent-R would be the one to get. Same price as the TinyCurrent, but it has the BNC connector facing the correct direction for connecting directly to an oscilloscope's input terminal.

    I do this stuff because it's both challenging and fun. I enjoy the precision of it. I just keep chipping away at it and eventually make progress. If my posts are of any use to others, then all the better: it all works best when everyone helps everybody else, because collectively we know more than any one of us individually. We've barely scratched the surface of what can be done. Synchronizing clocks among all the different motes and doing time division multiplexing among them would offer ultimate efficiency I think. The technology to do that is already known but the details of how to do it are not on display in a manner that's widely accessible.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    We've barely scratched the surface of what can be done.

    Openhardware.io gift coming. Please use it to replace your missing uCurrentGold with the proceeds. Someday I’ll contribute my own projects to these splendid forums, I hope.


  • Hero Member

    @Larson Thanks! I purchased it off Ebay, which says I should receive it by July 15,
    TinyCurrent-R.JPG
    though my guess would be probably sooner than that. I'll post a picture after it arrives.
    In combination with an o-scope, It should be good for those occasions where there's a need to capture very fast action in fine detail. 🙂



  • @NeverDie Super. It will be fun to see what you do with it. Glad you have the OC scope to leverage the tool. Cheers.


  • Hero Member

    @Larson You're doing the right thing by getting the PPK2. It will do 99% of what you want, and much more easily than an oscilloscope.

    By the way, in case anyone is interested, there are a couple of reasons why a direct-to-oscilloscope connection beats hooking a typical 1X/10X oscilloscope probe up to, say, a uCurrent Gold or TinyCurrent. The first is that, obviously, there's less noise involved because of the short connection. The second reason is far less obvious, though, which is that the typical 1X/10X oscilloscope probes make for fairly lousy 1X connnections. For measuring small voltages on a 1X connection, you're better off using regular coax or, better still, a direct connection and eliminate the coax altogether. Why? Well, the TL;DR is that oscilloscope probes are optimized for use as 10X (which really meas divide by 10), as explained in the EEVLOG video:
    EEVblog #453 - Mysteries of x1 Oscilloscope Probes Revealed – 29:49
    — EEVblog


    Meanwhile.... I've been trying to get Channel Activity Detection to work on the SX1280, but so far no joy. In some sense it's its own mode, because it "supposedly" times out automatically and returns to Idle mode after a fixed number of symbol periods that's set by SetCadParams. So, I'm puzzled as to what's going on and will have to take a deeper dive to figure this one out. Unfortunately, the library does not support CAD, so there's no working example to start from. There have been some alternative libraries posted on github, so I'll see if they shed any light on how to get CAD working.


  • Hero Member

    Well, this is a good example of how having a PPK2 helps to troubleshoot the CAD problem. We can see from the PPK2 that the CAD actually is activated, once per second, as per my code:
    CAD_activating.png
    So, just knowing that narrows down the problem considerably. The problem now is no longer that but instead why it isn't setting the IRQ flag to indicate that it has finished its detection cycle? The Rx completion flags aren't being set either.


  • Hero Member

    @Larson You'll want to add some jumpers to your BOM if you don't already have them:
    jumpers.JPG
    The above are two motes. The one on the left is used for measurement, and the one on the right isn't.



  • @NeverDie Super, thanks for pointing out the jumpers - very clear to see how they would be used.

    For a long time, I've wanted to make ESP programmer boards that would use springs to temporarily hold the ESP. I actually built one using pogo-pins and a 3-D printed housing pocket. It worked but was fiddly. I may try again on your radio carrier board but differently this time. I’d like to use stiff carbon steel music wire that would be mounted in drilled holes in the existing pads and create new pads on the back-side for mechanical-solder support. Some trace revision would be in order on the back-side, and Captain Tape could cover the new solder pads if needed. Think of it as a bed of nails. Carbon steel music wire is used in springs, I think, and that is what I'd like to use for its stiffness. Perhaps I’ll make the dimension between the rows of holes about 1 mm shy of the distance between the castellated indents. Then to use, push the SX1282 down into the field of springs getting 4 or 5 mm from the carrier board or until the springs start to splay out. If it works, the castellated indent would snuggly fit the wire if I can select the right gauge. One board could then serve different radios of the same class with the same pinouts. The downside may be that I have 16 new unintended antennae. Maybe I could trim these springs shorter after learning how it works.

    The compelling reason for this is to preserve the radio for later permanent installation elsewhere, if needed. There may be some performance degradation as the effective trace length would be longer. I have no idea of the electrical properties of this wire. I'll find out. I’ve got too many ESP’s that are permanently attached to dead testing, or otherwise abandonded, boards. What do you think of the idea?

    Atmega328P selection question: is this linked choice the right pin configuration for the footprint you used? There are so many other choices. Digikey is out of stock, but I'm presuming I'll find them elsewhere.


  • Hero Member

    @Larson AFAIK, any atmega328p with a 32TQFP package should work. Yes, they are in surprisingly short supply right now. Because of that, some people (like Great Scott!) have taken to desoldering them from Pro Mini's, which aren't cheaper but are easier to find. If you go that route, I recommend you buy some ChipQuik to make your desoldering a whole lot easier: https://www.amazon.com/gp/product/B0019UZP7I/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 But that's me. Maybe you have your own preferred method. Whatever works. If you have old projects you no longer use, now is a good time to recycle their parts.


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    What do you think of the idea?

    I think it would be easier and less iffy to simply solder it on as per usual and then use ChipQuik if you later wanted to desolder it and move it to another board. But again, that's me. That said, I somewhere have one of those springy jigs that I bought on aliexpress for programming virgin ESP8266's, and it seems to work fine--well, at least for the purpose of installing bootloaders. I never tried to do wifi with them in such a jig, so I don't know what the RF consequencies might be, if any. If you can tolerate some impairment, maybe it's good enough.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    ... then use ChipQuik if you later wanted to desolder it...

    Okay. One more item for my BOM and skill set. Thanks for the 32TQFP tip also. I do happen to have several Pro Minis and Nanos on hand since I bought them by the dozen - but they are so perfect as they are. Okay, I'll risk one and see how it goes. I am very excited to test the power difference between fuse settings and excluding the external crystal. Andrew Retallack wrote a great series on Beyond the Arduino for power savings and programming in C. I'll have to go back and look but I think it all was based on the external crystal.


  • Hero Member

    @Larson Here's all you need to know in one place on how to get to 100na sleep current on the atmega328p: https://www.gammon.com.au/power He covers all the different methods. TL;DR: burn your fuses to:
    External: 0xFF
    High: 0xDC
    Low: 0xC2
    and then run Sketch J from the Nick Gammon link. That's all there is to it, provided you have an external device/circuit to wake up your atmega328p.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Meanwhile.... I've been trying to get Channel Activity Detection to work on the SX1280, but so far no joy.

    Is there a CAD register that can be polled? In the SX1280 datasheet section “11.6.8 SetCAD” there is discussion of a CadDone IRQ. Maybe that can be used outside of the library? Maybe with its own interrupt? It looks to be bit 13 of the IRQ Register per table 11-73. I’ve never played with these radios but have found other devices (simpler devices) to be register friendly. Most of the references to CAD are in section 11. You, no doubt, have already been there. If so, I leave the comment for others.

    [edit: on second read I see you have already been to section 11 with your comment on SetCadParams. Hmmm... wish I knew more. I'll play with it when I get set-up.]


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Meanwhile.... I've been trying to get Channel Activity Detection to work on the SX1280, but so far no joy.

    Is there a CAD register that can be polled? In the SX1280 datasheet section “11.6.8 SetCAD” there is discussion of a CadDone IRQ. Maybe that can be used outside of the library? Maybe with its own interrupt? It looks to be bit 13 of the IRQ Register per table 11-73. I’ve never played with these radios but have found other devices (simpler devices) to be register friendly. Most of the references to CAD are in section 11. You, no doubt, have already been there. If so, I leave the comment for others.

    [edit: on second read I see you have already been to section 11 with your comment on SetCadParams. Hmmm... wish I knew more. I'll play with it when I get set-up.]

    Yeah, I'd say the Semtech SX1280 architecture is quite different than a lot of previous Semtech chips, which, you're right, in prior times were very register oriented. There still are some registers, but for SX1280 Semtech adopted a less transparent op-code architecture where you can issue commands--but in some cases there's no way to verify whether the command "sticks" like there is with a register oriented architecture, where you can always read-back the register to confirm that what you think you wrote to a register was actually written exactly as you wrote it. This is making troubleshooting relatively hard, because the chip has some internal states that you can no longer read like you could with a more register oriented architecture. Instead, you send an op-code over SPI, and maybe some parameters to go with it (the type and number of which can vary), which you "hope" works. I don't like it at all, because, among other things, it assumes that the documentation is 100% complete and flawless--and documentation never is. In particular, the SX1280 datasheet never gives the exact protocol for launching CAD, and whatever that protocol is, I seemingly haven't found it yet, despite testing numerous possibilities--though I may have gotten close. And in a system with more than one SPI device, what happens if there's some conflict in your SPI communication? How do you ever unravel what it is if there's no way to verify? Seems like heartache waiting to happen. I don't understand why the opcode system is thought to be better. Anyone know?

    Anyhow, Stuart's Projects never implemented CAD, and internally I'm finding it makes, IMHO, some seemingly improper assumptions about which IRQ's are assigned to which DIO's in how it operates. That makes it brittle. That's something one just can't know when looking purely at a library's veneer. Anyway, the good news is that late last night I found a different, more general library which claims to have a working SX1280 CAD example, so I'll be giving it a test drive soon. https://github.com/jgromes/RadioLib It's not radiohead, but it's a similarly ambitious library project that spans multiple different kinds of radios and multiple different kinds of MCUs. If the CAD demo code works, then I'll adopt the new library and drop Stuart's Projects. If nothing else, I admire the authors ambition to be the one library to rule them all. As I hate changing libraries, I truly hope this is "the One" library that can do that. 🙂


  • Hero Member

    Well, the Radiolib CAD example compiles and runs, and it nominally looks like it should:
    radiolib_cad.png

    I just need to introduce a separate LoRa transmitter to the vicinity to confirm that the detection actually works. I'm guessing the LoRa parameters have to be an exact match (SF at minimum and maybe other parameters as well). Then, sending a long enough string--and maybe reducing delays in the CAD detector loop--should lead to a detection.

    [Edit: Yup, I tried running the generic SX1280 Radiolib transmit example, with delay removed, and the CAD detector easily detects it. It works! 🙂 🙂 🙂 ]


  • Hero Member

    Since the Barebones v001 is, after all, a test platform, I'm going to assemble a mote and SX1280 adapter that use Dupont headers. The reason is that the 8 sense pins on the PPK2 work with Dupont wires, and I don't see an easy way to make those work with machine pin headers. No change in the PCBs is required. @Larson You may want to assemble your motes this way from the get-go.

    By the way, can anyone here recommend where I can buy "good" Dupont wiring and connectors? If I buy from China, I seem to often get very loose-goosey connections.

    P.S. I could be wrong, but the RadioHead library seems to have stopped progressing. None of the newer LoRa chips are in any of its examples. Too bad, as it was a very progressive library in its day. That leaves RadioLib as the library to rule them all. However, it has a very different overarching paradigm than, say, StuartsLibrary, which was easier to grasp.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Dupont headers

    My plan is to use female headers on the Barebones board, then to use doubled long-legged male headers on the SX1280 adapter board like these from Digikey. It all stacks together and bed of nails will stick out the top of it all. That way the PPK2 Dupont females can nicely plug onto the any of the protruding males in the stack that I select to use as a signal or interrupt. Again, I risk a bed of 16 inadvertent antennae with all that metal in the air. I can always snip-off the pins I don’t use. PPK2 is expected on Monday!

    I spent the day shopping for parts at Aliexpress, Digikey, and Amazon. I found some 328P's at Aliexpress. Could be some time for the Aliexpress parts (SX1280 module). In the meantime I'll be learning KiCAD. I'm hoping that Eagle and KiCAD might allow file swapping as Eagle is familiar ground for me. Or ... I could just take the easy path and go directly to OSHPark since you have made it so easy.


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Dupont headers

    My plan is to use female headers on the Barebones board, then to use doubled long-legged male headers on the SX1280 adapter board like these from Digikey. It all stacks together and bed of nails will stick out the top of it all. That way the PPK2 Dupont females can nicely plug onto the any of the protruding males in the stack that I select to use as a signal or interrupt. Again, I risk a bed of 16 inadvertent antennae with all that metal in the air. I can always snip-off the pins I don’t use. PPK2 is expected on Monday!

    Somehow I had gotten it in my head to use extra long female headers (such as these, https://www.amazon.com/gp/product/B071GTP5V6/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1, or similar) on the adapter board and then regular female headers on the basic atmega328p PCB. Maybe it's a wash?


  • Hero Member

    @Larson KiCAD 6 allows for importing Eagle projects right from within KiCAD 6 itself. Not sure what options, if any, might exist for exporting to Eagle. I think you'll like KiCAD 6. It's pretty easy to pick it up--much easier than earlier versions. I previously used Diptrace, because it was so easy, but I've since moved completely over to KiCAD 6 because it's just as easy, but also more widely supported in terms of parts libraries. Also, unlike Diptrace, it makes sharing projects a snap--just create an archive (literally a one menu click operation), and share the resulting zip file.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Somehow I had gotten it in my head...

    So many ways to cook an egg. The pleasure is in eating it. I'll take a picture of my wedding-cake-of-a-board stack when I finish. It may not be until July at my pace.

    Re KiCAD: I look forward to trying. Recently JLCPCB made me learn EasyEDA and it really went well. Learning Eagle took me a week the first time, 2 days the second time, and still... I have to retrain. That is the joy of it all, right?


  • Hero Member

    By the way, I've recently been reporting some other progress on the SX1280 on my radio-comparison thread: https://forum.mysensors.org/topic/11954/most-reliable-best-radio/27?_=1654402718278 For things that are both battery operated and subject to remote control, the importance of being able to quickly wake them up at a moments notice, but with minimal ongoing energy drain, is an important topic. Examples: key finder fobs, remotely opening/closing blinds at the push of a button, etc.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    reporting some other progress

    Yes, I have been there, though not lately. Thanks for the reminder. What great information and exchanges.


  • Hero Member

    From the perspective of having some kind of general purpose platform--not just for testing but as a "go-to" for general use--it would be nice to have some kind of project box or enclosure of some kind for it. That would prevent things in the environment from pushing up against the electronics/PCB and possibly shorting it out. Anyone have any ideas on what form that should take? There's always the option of custom 3D printing something, but if there were a box of the right size already out there, that would be much easier. In that case one could customize the PCB to fit it precisely instead of 3D printing a box to precisely fit the PCB. Having a nice enclosure is one of the things that typically separates store-bought sensors from hobbyist projects.

    By the way, the SHT45 TH sensor that I mentioned in the OP is now available on mouser. Unfortunately, it seems they nearly doubled their asking price over what they had earlier projected, so that's a bit of a disappointment. I guess these days a lot of chips are marked up due to the widespread shortages going on.... The chip itself is quite small, but it only has four landing pads, so I'm thinking that hand soldering it should be manageable. A simple adapter board, like this one for the SHT40, would allow it to easily fit the platform:
    sht40.JPG
    because the platform's pinout already anticipates adding up to two I2C devices without any fuss, like thus:
    TH_addon_1.JPG
    TH_addon_2.JPG
    FYI, I updated the project page with a bunch of photos.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Anyone have any ideas on what form that should take?

    Looks great! I’ve had good luck at Aliexpress with a variety of boxes like these. Some boxes have mounting lugs on the bottom. Your board has no space for mounting holes. I could help with the redesign??? Then I'd use stand-offs to get to the lugs and suspend the batteries in the air off the bottom. The antenna could be curled inside the box, but I've found that to have a negative impact (probably the polairity thing.

    [Edit: Forgot to say that I've thrown in the little bags of desiccants for good measure. I find them in my pill bottles.]



  • @NeverDie I've made progress. I've ordered these items (mostly radios):
    SX1278
    SX1280
    nrf24012mg E01's
    nrf2401+
    Bunch of antenna parts
    TPL5110
    Atmega328's
    I cannot find any SX1262's and after your other post ("Best") I see that this is the darling to have. Any idea of where to find some?

    Fun to see the photos of the current meter in sleep action on your other post.

    One addition I would like to make to your boards is a GPS chip. The idea would be to walk about in a field and collect RSSI and SNR data. Combining these elements would give a pretty good picture of signal vs the 2-dimensions of GPS data - for each radio and different modulations, spreading factors... Trouble here is that there are too many parameters to play with. I see Excel graphics coming into play. I have no experience with GPS, although I own a few of the chips.


  • Hero Member

    The ones I've tried so far are these: https://www.ebay.com/itm/202574135410?hash=item2f2a5c0072:g:H9EAAOSwLuldcige Maybe it was luck, but the seller delivered fairly quickly, and they were very well packed. They allegedly contain TCXO's, so that presumably makes them better than those moules which don't have TCXO's.

    I just today received these Ra-01SH, but haven't tried them yet: https://www.aliexpress.com/item/2255800961841511.html?spm=a2g0o.order_list.0.0.20411802pmZPEx&gatewayAdapt=4itemAdapt
    I have custom adapter boards for them though. At the time I ordered them in April they were just $3.31 each, but now the same seller is asking $4.24. Delivery time was pretty long (longer than originally promised). So, you may want to shop around. If this is the new market rate, then I would go for the Dorji boards instead, because for the money you at least get TCXO's with the Dorji's, and they allegedly passed FCC. On the other hand, I've had good luck with Ai-Thinker in the past.

    There are some other brands out there as well, but these are the only two for which I made adapter boards.


  • Hero Member

    @Larson I don't know how well GPS location works indoors, but it if somehow does that would be interesting. If it has gotten small enough and cheap enough and low power enough, it would be interesting for clock synchronization as well, though there are other ways of doing that.


  • Hero Member

    Wow, I just checked, and GPS receivers have really gotten small, especially as compared to 5 years ago. Just 7mmx7mm in size: https://www.mouser.com/ProductDetail/Quectel/LG77LIAMD?qs=zW32dvEIR3sKRLNP92tehQ%3D%3D

    That's way smaller than the old Adafruit one that I have: https://www.adafruit.com/product/5440
    which is gigantic.



  • @NeverDie Thanks, once again. Done and purchased (4 1262's, and 2 1276's (ra-01SH)). I don't know why google and I couldn't find the1262's, nor Digikey, nor Ali, nor Amazon. So I'm on the slow road. I don't expect you to wait for me but your records in this forum are a standing education for all that follow. I'm sure I'll have observations/questions if you are still there.

    Per my GPS thinking: I was thinking outdoors in an open field. I know your objective was through a reinforced footing, across the house, and up a floor. For that environment I would map the house into a grid with surveyor's cord and walk a defined pattern, clicking a button for every grid point I cross. Then I'd go to the yard with the same idea. My wife tells me I'm hard to live with... imagine that.


  • Hero Member

    @Larson According to AI-thinker, the Ra-01SH is an SX1262, not a 1276. The SX1262's are more capable, whereas the 1276's are older generation. https://docs.ai-thinker.com/_media/lora/docs/ra-01sh_specification.pdf AFAIK, the two adafruit modules I got for trial purposes were SX1276's.

    Since you'll be trying more than just the Ebyte module, let me know if you'd like me to post the other adapter boards also (e.g. for the Dorji SX1262, the Ra-01SH, and the nRF24L01). The work is already done.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    That's way smaller than the old Adafruit one that I have: https://www.adafruit.com/product/5440
    which is gigantic.

    At some point, like this, bigger is better for me. Imagine the size of the GPS in modern phones. I prefer the Adafruit type that has breakout pins and 'hold-my-hand' tutorials. We live in a golden age. I have to go find my GPS boards that i think I have. It has been some time and I've always wanted some purpose. This may be the time.


  • Hero Member

    Definitely agree that it's the tutorials that make the adafruit hardware worthwhile, typically much more so than the hardware itself.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    let me know if you'd like me to post the other adapter boards

    The other adapter boards would be great... but I thought I'd earn my way into it by working with what you have already posted for the SX1280. To date I've been collecting pinouts to study the patterns so I could understand the template(s). What ever you post is a gift and I thank you. I'm sure that others to come will also enjoy. You have built quite a platform and I'm inspired.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    According to AI-thinker, the Ra-01SH is an SX1262, not a 1276.

    As I'm shoping around I found the Ra-01 Lora, but it was assocaited with the 1276 per this link you offered: https://www.aliexpress.com/item/2255800961841511.html?spm=a2g0o.order_list.0.0.20411802pmZPEx&gatewayAdapt=4itemAdapt&aff_fcid=d9908c021fe34eeeb0ea05b879ca4432-1654498510220-06752-_uYd1nh&aff_fsk=_uYd1nh&aff_platform=api-new-link-generate&sk=_uYd1nh&aff_trace_key=d9908c021fe34eeeb0ea05b879ca4432-1654498510220-06752-_uYd1nh&terminal_id=afb1662bfbca4bd68d5ee03a630ea8c7&afSmartRedirect=y.

    Given that I haven't studied the datasheets, I don't exactly know the shape-shifting ability of one chip to act as another. Not sure where to go with this one - but I'll know more when they arrive. I'll work on it in the AM when I'm fresher.


  • Hero Member

    @Larson When you hover over the different modules on that webpage, it will tell you the name of the model. They're all different.



  • @NeverDie Groovy. And good night. So much to learn.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Anyone have any ideas on what form that should take?

    Second effort: This link shows a type of box with mounting points on the bottom. It would be nice if there were a PCB footprint for the holes, but I could find none. Using a paper rubbing and a set of calipers one can create their own footprint and build the PCB to that dimension. For any hard wires that must be passed through the box, I've been using cable glands like these for a waterproof enclosure. See the Cave Pearl Project for a different deep-sea approach,


  • Hero Member

    I posted the rest of the radio module adapters to openhardware.io.



  • @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Not sure where to go with this one - but I'll know more when they arrive. I'll work on it in the AM when I'm fresher.

    How confusing. On the EC-Buying Ali Store they show associations of the RA-01 with SX1262, SX1272, and SX1278 in titles on separate pages. Each of these pages show a variations on the RA-01 title (S, H, SH, SC...). I'll take your word for it. So it looks like all 6 radios I ordered last night are SX1262's then.

    Found my GPS! It is really big & heavy too.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    I posted the rest of the radio module adapters to openhardware.io.

    Wow. Thanks. I'll be sure to report back on what I come-up with.



  • @NeverDie Been gone today so unable to play. Thanks again for generously sharing your work. I'm just now starting to look at the files: so cool! I like your broad power traces and skinny signal traces. And the pads on the radio chips are really tiny. I suspect these design choices are not accidental.

    Look out OSH Park, here I come.


  • Hero Member

    @Larson One thing Diptrace had that KiCAD lacks is a built-in auto-router. As a result, I manually routed as fast as I could so that I could place the order without delay. I've heard there are auxillary auto-routers. If any of them are any good, it would be a nice tool to have. Drafting the schematics goes pretty fast; it's the routing that soaks up the bulk of the time.



  • @NeverDie In Eagle, I found that the auto-router gives no joy. Seems to be that the art of the board is best done manually.

    I'm just now looking at one board (DRF1262TG) in OSH Park that I've uploades. The view is much better than looking at the *.svg files. The radio pads look like even I can hit them with solder. Gave me a better feel. Golden age... thank you again.


  • Hero Member

    @Larson This time using female headers, I built a new platform and Ebyte adapter, as discussed earlier.
    ppk2_rigging.JPG
    I expect this version will be fully Dupont compatible with the PPK2 probe pins. Unfortunately, if you look carefully you'll see that the adapter PCB covers up the nearest header pin hole beneath it on either side of the board. Ooops! I'll have to fix that in the next revision of the adapter board. For now it's no biggy, though: it's PPK2 access to the pins on the adapter board that matter most, and those are now fully exposed for probing.


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie The radio pads look like even I can hit them with solder.

    When I'm designing module PCB landing pads, I almost always make them longer than what the datasheet recommends to make orienting the module and soldering it in place easier. In contrast, the datasheet always specifies the absolute minimum.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    if you look carefully you'll see that the adapter PCB covers up the nearest header pin hole beneath it on either side of the board.

    Yea, but a Dremmel snip job would have those two pins accessible in a flash! In my hackish world, there has to be three errors to warrant redsign... unless it is an unrecoverable error, of course!


  • Hero Member

    @Larson Are you able to get input to work on any of the 8 PPK2 sense pins? Mine isn't responding at all. They all read high, even if I connect one of them directly to PPK2 ground. Matter of fact, I'm not even getting any voltage out of the logic analyzer's VCC pin. If yours is working, then maybe mine is defective or something.

    Where were you able to get yours from? The place I ordered from no longer has them in stock. I'm debating whether to backorder from mouser. Argh. I hope it doesn't come to that. Weird that the current portion of the PPK2 is working, but not the logic analyzer part.

    I've submitted a ticket to Nordic and contacted the seller, but of course nothing happens very quickly and I probably won't hear from them anytime soon.



  • @NeverDie The PPKII arrived yesterday! I've only cracked it out of the box and haven't tried. I'll do so next. Been spending my time in KiCAD tutorials, looking at your boards and taking care of family! I'm like an excited dog in a 3-D field of fire-hydrants! Never enough time for a slow-reader like me.

    My PPKII source: DigiKey 5/24/22 order. Here is the scoop off the invoice (most importantly the part no): PART: 1490-NRF-PPK2-ND MFG : NORDIC SEMICONDUCTOR ASA / NRF-PPK2 DESC: POWER PROFILER KIT 92.50000 92.50 COO : POLAND ECCN: EAR99 HTSUS: 8543.70.9860 ROHS3 COMP REACH UNAFFECTED 25-JUN-2020
    It sure came fast for being back-ordered.

    I also received a bunch of other solder stuff you recommended and a solder plate. Again, too excited, but life is getting in the way. Radio’s are on their way, mostly from AliExpress. Too bad they fractionalize one order; now I’ve got about a dozen different order-tracking email threads.

    PPKII test: I’m planning on a vanilla ProMini with and without the conventional crystal – per your tutorial. I will throw in a signal cue on a pin to test the logic analyzer thing. Will that be sufficient to test? Hope to report by the end of the week if the distractions end.

    Then I’d like to try the PPKII on the Darrah Trig Board; I know, I can’t read the deep sleep with a PPK, but it will be a good first-try for me with the Trig Board.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Matter of fact, I'm not even getting any voltage out of the logic analyzer's VCC pin.

    Maybe a stupid question... but are you powering from the PPKII source, or the device-under-test battery? Does it matter? I know nothing about the PPKII, yet. But I have read that the burden voltage is an issue even on the PPKII. I have no idea if the LA is complicated by this.


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Matter of fact, I'm not even getting any voltage out of the logic analyzer's VCC pin.

    Maybe a stupid question... but are you powering from the PPKII source, or the device-under-test battery? Does it matter? I know nothing about the PPKII, yet. But I have read that the burden voltage is an issue even on the PPKII. I have no idea if the LA is complicated by this.

    I've tried it both ways, and I'm just not getting anything out of the logic port.


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    Will that be sufficient to test? Hope to report by the end of the week if the distractions end.

    I imagine so.



  • @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    I know nothing about the PPKII, yet. But I have read that the burden voltage is an issue even on the PPKII.

    And, I think I learned about the PPKII burden voltage from you!


  • Hero Member

    @Larson said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    @NeverDie said in Anyone using/tried the E28-2G4M27S 2.4Ghz LoRa SX1280 27dB module?:

    I know nothing about the PPKII, yet. But I have read that the burden voltage is an issue even on the PPKII.

    And, I think I learned about the PPKII burden voltage from you!

    The PPK2 seems to work fine when powering the circuit whose current it is measuring, but if externally powered then, yes, for some reason it seems to choke the DUT.

    Because the PPK2 is out-of-stock everywhere, I decided that rather than be held prisoner by whatever lengthy return/warranty cycle for my PPK2 is likely to be, I would upgrade my o-scope to one that can do integrations and sell my old scope, which can't do integrations. New scope should arrive on Thursday.

    If you're wondering how that works, this explains it:
    EEVblog #662- How & Why to use Integration on an Oscilloscope – 19:53
    — EEVblog

    As you can see, the UI is nowhere near as nice as the PPK2 for measuring current consumption. Perhaps offsetting that somewhat is that the o-scopes resolution should be better: the PPK2 has 100,000 samples per second, whereas these days a decent entry-level o-scope will commonly have 1 giga-samples/second.

    I still like the PPK2, and I look forward to exchanging the one I have for one that works.



  • @NeverDie I have no experience with an O. Scope, or a PPKII. I presumed the OS gives one much more dimension of analysis. But as indicated my Harbor Freights DMM delivers nearly everything I need. Sure is fun to listen to Dave Jones. The man is a source of knowledge and excitement spiced with humor.


  • Hero Member

    Good news! My PPK2 works after all. After experimenting, I determined that '"VCC" on the logic port is not a voltage source, as its name would imply. Instead, it is a voltage sense pin. So.... the way to make the logic port work is to wire the logic port VCC to the VOUT (or to whatever VCC that's powering your project). After doing so, D0 through D7 work as you would expect.

    Also worthy of note: there evidently are no internal pull-up or pull-down resistors on any of the D0-D7 logic port sense pins. So, if, for example, you give D0 a high pulse and then disconnect from it, D0 will tend to stay high until it receive a low pulse.

    Happy I don't need to return/exchange the PPK2 after all. 🙂


  • Hero Member

    @Larson Something I only just recently started using in the last couple of days that you may like: 0.4mm diameter Kester Rosin solder. It's ridiculously thin, but for soldering radio modules onto boards, I'm finding that I can more precisely put just enough solder exactly where I want it without having to apply solder flux to the module afterward.


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