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

ey'd have a different ISP, or, if not, can at least pass your traffic to someone else on the LoRaWAN who has a different ISP than you. If you were also running Amazon Sidewalk, then you'

@NeverDie. Thanks for your write-up. Before I lose my train of thought and go look at StuartsProjects I have to ask about the EasyEDA design: doesn't it make TX/RX much better with no groundplane around the antenna? I've just completed a 433 MHz project and found that I was better to get the TX side way off my groundplaned board. Also, I've noticed that other ESP8266 breakouts dutifully remove the groundplane from breakout boards that would be near the ESP's built-in PCB antenna.

I don't know much about radio's so can easily accept any comment for the better, or even ridicule. I've learned as much as I can about radios from Andreas Spiess. He would simply test the difference with a RF sensor.

@NeverDie said in Most reliable "best" radio:

would last... ready for it?.... 1,537 years!

Have you considered comedy as a profession? I love your postings. The self-discharge of the human is another limitation. Unless, of course, you have a couple of Methuselahs in your progeny and a good set of instructions. And I know you can write good ones.
Thanks for the post.

@NeverDie. Thanks for the comment. I'm not sure if I've got that ground-plane radio interferance thing right. Maybe there is a SMD socket thing in which a radio could be clipped so you don't have to commit a radio to the board to find out. I've not seen one but I've not looked. Maybe it is time to invent one with springs to receive castellated edges. A jig like that would also serve ESP8266's. I like the PTH sockets for this kind of experimentation.
The idea of sawing off the top just north of the TXEN/RXEN connections is good. Maybe you could do that after mounting so you could test before AND after. That would be definitive.
On the other hand a redesign and reorder from OSHPark can't be that much of a setback. I really enjoy their service. They happen to be less than 5 miles from my home - but they ship globally. Small world.
Let me know what you learn. I'll learn with you much as I have been doing with hundreds of your other posts - and I thank you.

@NeverDie Sorry to bother again... but I gotta say this Hartley traning video has been monumental. I always thought the world was divided into AC and DC. NOW, I think I get it: DC circuits flipping on and off at a SIGNAL frequency are actually AC just with a different voltage basis. The KEY, Hartley says, is that the energy is not in the trace, but in the field during the rise and fall of voltage. This is also helping me to finally understand inductance. WHY didn't they say this 40 years ago in school? Oh, perhaps I was sleeping as I did.
This is a breakthrough that may lead me to understanding antennae theory and a bunch of other stuff. I thank you for the introduction. I gotta go find this Hartley fellow to thank him.

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

Anyhow, if you find out anything more, I'd be interested.

Eric Bogatin, master and professor of signal integrity, gave this presentation at an Altuim conference. At about 42:00 he talks about 7 Habits of Good Design. This, again, has more to do with PCB design and not radio performance. I have a suspicion that several radio boards I designed failed not because of the transmitter, but because of bad PCB design. I can make a failed transmitter (whip antennae) board work by putting the 433 MHz transmitter on a 7" leash away from the board. Now that is a sign.

@ejlane - Thanks. I'm just now learning of the EMI/EMC testing required for commercial products and FCC requirements. While that exceeds the requirements and budget for my home projects, I do think that I might employ the pre EMI testing that one can do with a scope and probes. That may drive me back to school to learn scopes!

@ejlane & @NeverDie: Amazing technology that was available for $1 was … too hard to believe. Even $5 for a ProMini is pretty mind-blowing. Not that I buy commodities, I do buy these components a dozen at a time to save on shipping even when it is ‘free’. I laugh at myself when I spend a week of my time on a $2 chip and then wonder how I can rework it from a PCB (never worth the attempt). Compared to any other hobby or habit this radio-electronic stuff is cheaper than cooking top-ramen at home.
BTW, thanks for the radio discussion posted last week. I will read and learn later.

@NeverDie, Thanks again for all the blogging on this subject. If you have not yet ordered your custom low-noise PCB, I had one design idea. If you flip the ProMini orientation end over end most of the traces will be shorter, especially the RX/TX lines. I’ve not examined the code, but I’d think that the RX/TX connections have the most signal activity on the board, thus EMI potential. I like how you keep all the traces on one side. That should solve the interrupted ground-plane problem we learned from Rick Hartley above.

It is far more fun to roll-your-own. Alternatively, I was thinking … I just checked the Moteino breakout boards from Felix at LowerPowerLabs to see if those would work with your Ebyte radios: too bad, different pinout. I just bought a few Moteinos (915 mhz) boards to save myself from my low-quality solder jobs and shaky hands – only $13 but I have to add my own radio or spend another $7. Everything I've seen from LowPowerLabs has been high quality.

@NeverDie. You are way out there, man! Thanks to the references to the other boards made by you. What fantastic contributions to the maker market.
I suppose D20 and D21 are the same as PCINT6/XLTAL1 and PCINT7/XTAL2? I once reassigned RX and TX on an Attiny85 to RX and TX (edit: output functions) as I was pin limited. It took some doing, but that is the beauty of these multifunction pin assignments. The code, if I remember, had to be in the loop after a delay in the setup; that gave me a way to access the RX/TX pins again to reprogram if necessary. Maybe there are similar challenges with bypassing the crystal.
@samh. So you are setting power levels on the fly. Very clever.

@NeverDie: Yes, as you describe elswere, and taught me, the design trade-off parameters are frequency, bandwith, dwell time, bit transfer rate, power demand, and most importantly, range. I'm looking forward to your findings.

Regarding the low reciever current: don't know about the FOB's but I have found the transmitter power to be key. My design has the "always on" reciever connected to mains. so I don't worry about that power. But the battery-limited transmitter devices are brought to life and triggered by the signal pin of the SR501 sensors that is high enough, long enough to complete a transmission, or several. The HT12E (encoder) chip is connected to the SR501 pin is fired and sends the settings of the dip-switch pin hi/low settings that is recieved by the always-on HT12d (decoder) that the Atmega 328PU can understand. I think the HT devices are MCUs in a different form, like what I imagine a FPLC to be like... don't know for sure. Why do I drone on? Because of the HT12D and HT12E pariings are very specific and very low on power demand due to their design. When I built my configuration (6 years ago) I knew more than I do now. But I'm relearning more. Andreas Spiess, Great Scott, Big Clive, and YOU, explore this stuff extensively, and I thank you all.

In summary, my repeaters and base RX station are mains powered so I don't worry about power & batteries. The primary focus for conservation of batteries is on the TX/Motion devices. Everything downstream of TX is mains powered or can be suitably backed up in the short term.

@NeverDie Yes, you are correct: the HT12D datasheet indicates that multiple signals must be recieved before the enable pin is activated. I think the 'multiple' is a count of three and there is probably a preamble in advance of the main message of high/low settings. The transmitter, again I think, just keeps sending the message until the SR501 drops power (2 seconds on the minimum settings). I get alot of double hits because of this. Good to know about the noise and history. Thanks.

@NeverDie said in Which PCB fab do you currently like the best?:

higher than quantity 5, then it seems to get kicked into a slower queue

Well, you could play the game of ordering 4 separate orders if you wanted 20 boards. Seems silly... but if that is their system.... I always enjoy the minimum order so I can find my errors, then order the updates, and find my errors, then order the updates. Life is itterative.... until it isn't. What a blessing to have so much technology at such a little price. If you make a mistake you lose a little and remember the error.

@NeverDie Just for clarification, you are not asking about assembly, right?

What a great thread (inquiry).

I've relied on OSH Park for PCB manufacturing. Never have I found a mistake that was not of my own making. But for assembly, I'm really impressed with my one JLCPCB experience - and the parts availability (LCSC, I think). Their online CAD program (EasyEDA, I recall), was a small hurdle but easy enough.

@NeverDie Yea, I think I knew you upversioned the silkscreen. I think I remember you commenting on it. Looks pretty. BUT in my effort to add to the community, since I typed it for my self for my V001 boards, I thought I'd share it incase there is anybody like me with V001.

I like the V003 upgrades, specially that reset bypass via as discussed with @alphaHotel . Maybe I'll try it. I've got so much into my little V001's (yours actually) that I just can't give-em up. When I get the boards rigged up with radios, GPS (on the USART bus) and SD Card reader (on the SPI bus with a different CS), I'll shoot and send a picture in the spirit of a party!

Here are the pin labels for the V001 barebones board for mounting on headers. The document I prepared for this wouldn't upload, but had nice lefthand/righthand orientations. This made it easier than having to open the CAD file everytime I needed to make connections.

But here is what I did in MS Word:
Turn on grid set spacing to 0.1"
Turn on ruler
Copy the below text
Align to the right or left as you wish
Font Calibri 5.5
Verify spacing (14 pins = 1.4")
Print

I also made columns and multiple copies of the below with both alignments. I have two boards built. Maybe you have more. Hope it helps.

GND
D5
D7
D9
D10/SS
D11/MOSI
D6
D8
A0
A1
VCC
GND
A5/SCL
A4/SDA

VCC
D4
D3
D13/SCK
D12/MISO
D2/INTO
A5/SCL
A4/SDA
A3
A2
VCC
GND
A5/SCL
A4/SDA

DTR
RX TX
TX RX
VCC
X
GND

[8/6/22 edit: reversed TX and RX as noted above - just incase someone has use for it]

@NeverDie said in Most reliable "best" radio:

because the resonate frequency seems to change

Ahhh, I have something to offer. I remember way back when playing with piezo buzzers (something that is part of my mole project and in use today unfortunately) I remember incrementally changing the PWM frequency and duty cycle in the loop. I may be off base because I really don't understand what you are doing. But I remember that there is a sweet spot (resonant frequency, perhaps) where the sound would just pop. I've seen this in vocal quartets too (we are talking humans) when they hit some vibe some kind of God's amplifier gets invoked. It is really cool unless one has hyperaccousis, as I do. So I run an hide, but marvel at the science.

@NeverDie said in Most reliable "best" radio:

compare the design in the photo against another design which might use, say, a CR2477 or a CR2450 or a CR123A, etc. Probably somewhere someone has built a coincell simulator to answer these types of questions.

During dev, I try to overpower with big batteries, or lines to sort it all out before playing with the smaller cells. Understand the demands first, then find the cell that can deliver. The LIR2450 seemed to deliver a good punch of curent that can carry radio transmission peaks of a ESP8266, 400uF caps helped. Nice thing is that you can control the timing of the peak audio with any other peak load... like a radio or something and prevent an overload.

@NeverDie Soldier on, my friend. I love reading, but I've got nothing to add other than to report that I'm moving on to the radio portion of the barebones design. Maybe I do have something to add: I found that having JLCPCB/LCSC fabricate parts was really easy and not very expensive. The required EasyEDA design environment, I recall, linked LCSC inventory with JLCPCB quite seemlessly. As usual, for me, the learning curve took a long time. I think there were limits that wouldn't allow for exotic parts. That is not a problem for me and my simple ways. But shipping confusion did not exist as it was a combo thing. The minimum order of 5 and the single-sided fabrication were limitations that I could work with. Manually soldering SMD's is really hard and JLCPCB makes it so easy.

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

...but I happen to think running from a crystal oscillator is generally a bad idea for a battery powered application...

No, don't change the design. I think you have a platform with a specific low power intent - including the education of others (like me). Matter of fact, I've got several battery projects that would be FAR better by changing to the on-chip clock, and new core. And so far, we are only using the 8 MHz setting. In the MiniCore the choices go to 1 MHz.

Back when I was... on PIC's... I bought 32 KHz crystals to minimize power. I just didn't know enough to use them and I still don't. But I'm working that direction and you have helped A BUNCH including you're idea of friends sitting around the table exchanging bits and bytes in a MISO/MOSI/SCK kind of way. I'm gathering that if you have control of the clock, you could have it all.

Besides you, Kevin Darrah, and Felix @ LowPowerLabs have also made great contributions to the low-power idea. I just haven't dedicated enough energy, yet, to their efforts.

16 MHz is impractically fast when so many designs just need low power.

I wanna go back to school,
DogWithA_Bone

@NeverDie said in Bootloading a barebones arduino:

You and a group of friends could sit around a table and pass bits and bytes to each other using an SPI communication protocol.

Passing bits and bytes is probably more fun that sitting around a table and passing digs and barbs! I don't know: maybe my friends ARE binary!

[Edit: I forgot to say anything about the content of your SPI protocol story. That was a great story; I feel badly for not thinking about the SPI connection at all. Now it is ingrained. ]

@NeverDie Talking about virtual ports, HWFC, and chain breakage is way out of my experience. But I'm impressed that you are thinking at that level.

On Baud Rate missmatch: Lacking an OScope, I suppose I could hook the PPKII to the TX of the barebones and transfere values of (2^8)-1, or 255, to see what the exact timing looks like. Serial.print(255, BIN) should do it, right? The datasheet tells me the max sampling speed of the PPKII is 100,000 S/s, so 9600 baud should show pretty clearly and enable me to fine tune what baud the MCU is generating. In a forum post I asked you what the trade-off is for using the internal crystal; you answered "accuracy". That is what got me thinking and looping on different baud rates. Serial Monitor was giving me 12#$, or the like, when I was expecting 1234 via Serial.print, so I knew it was close.

How tight are the radios to baud support they get from the 328P? I would imagine the internal crystal baud rate is dependent on voltage. Maybe some formula exists in the 328P datasheet that allows for adapting this on the fly.

@NeverDie said in Bootloading a barebones arduino:

Something is amiss then.

Probably true, and thank you for your commenting.

I think all my USB-TTL converters are based on cheapo CH340G chips. But, to date, except for my blunders, I've not had a mismatch between the SW and FW baud rate that is so slight and I'm using the same wire length and converter as before(cheap & near, pluggable wire).

I think I misstated the idea that that the bare bones "can't exactly keep up". The reverse is the case: the barebones MCU is faster than the IDE/USB-TTL combo. None-the-less, the timing is off so that Serial.print yeilds some ASCII characters instead of numbers. Incrementally changing the baud rate in the loop enabled me to test different rates. And what the serial monitor in the IDE thinks is 9600 baud, it is best expressed when the chip hits a baud rate of about 9000. Make sense? I'm imagining that the same is true if I were at 115,200, only relatively higher.

In development, as I am, I always default to 9600 until I gain some confidence. Sometimes going slow is the source of my problem when chips are going so fast.