Introductions and Range Issues

[sundberg84]

@mathea90 said in Introductions and Range Issues:

If you are using LE33s, what exact capacitors are you choosing?

This depends, but mostly 4,7uF. Sometimes It works better with a 47uF cap. '

Do you have low ESR electrolytics?

Just regular cheap electrolytics caps.

good choice of yours to use high quality charger / phone adapters

Yes, and cheap are also very unsafe as well.

What kind of behavior do you notice from bad radios?

Most common, no reply / no connection at all unless very very close. Not that common that it works say 6m and not 15m.

2.3.0 version

I have been around since < 1.6 and I have never noised any bigger changes between the versions. I have understood there are some discussions around the RFM69 radio. I have nodes still from 1.4 and most from 2.0-2.2 and one from 2.3 but even though some are upgraded several times in different versions (same hardware) they perform the same. This makes me wonder still about the hardware quality of the radio...

[scalz]

2.3 issues mentioned are regarding rfm69 only, in special case: higher packet rate. even if it's weird it was ok with 2.2, it's mostly because for the moment there is no packet buffer/queue for rfm69, which exists for nrf24.

when you get better range/rssi etc by changing rf module, then it can be a bad/clone etc rf module.
when you get same range with all your modules, and range is poor, check points mentioned above ;)

[joaoabs]

@sundberg84 I'm wondering if you use signing?
I could understand from other threads is that the usage of signing afects the performance of the NRF's becasue it somehow "pushes it to the limit".

[Anticimex]

@joaoabs the "pushing to the limit" is just that with signing, max sized payloads are sent. And with increased size, the propabiliy for corruption increases.

[sundberg84]

@joaoabs - no, im not using signing on the Nrf24l01+ network.

[titvs]

Today i made another couple of tests with a repeater to see if i can get signal from my first floor to the ground floor (where is the gateway) with promising results. Still waiting for my NRF24/PA/LNA to arrive still.

I was wondering if its ok to set the MY_RF24_PA_LEVEL to HIGH on all powered nodes (sensors, repeater and gateway), or the performance will be degraded?

Talking about the frequency ranges, i have a mesh of wifi Ubiquiti Unifi AP's in my house, which are able to do a RF scan and show me the channels that are more utilized. It seems the more crowded channels here are (20 MHz): 5 (2421-2443), 6 (2431-2453 MHz), and (40 MHz): 3 (2401-2443), 5 (2411-2453) and 9 (2431-2473).
With this in mind, im setting up my nodes on channel 2 (MY_RF24_CHANNEL 1 if im correct) where there is 0% utilization.

PS: i have an original Nokia charger rated at 5v on the label but actually gives out 7v dc... Had another one rated at 5.4v but i measured aroud 7.6. Are these chargers supposed to work with a pre-determined load?

[Mathea90]

@titvs said in Introductions and Range Issues:

I was wondering if its ok to set the MY_RF24_PA_LEVEL to HIGH on all powered nodes (sensors, repeater and gateway), or the performance will be degraded?

Talking about the frequency ranges, i have a mesh of wifi Ubiquiti Unifi AP's in my house, which are able to do a RF scan and show me the channels that are more utilized. It seems the more crowded channels here are (20 MHz): 5 (2421-2443), 6 (2431-2453 MHz), and (40 MHz): 3 (2401-2443), 5 (2411-2453) and 9 (2431-2473).
With this in mind, im setting up my nodes on channel 2 (MY_RF24_CHANNEL 1 if im correct) where there is 0% utilization.

Hi titvs,

• I can remember that initially the MySensors library set the NRF24L01s power to "HIGH" by default. I just glanced at the API page to verify if this is still the case but it seems that now the default value has been set to "MAX" which is the highest possible power setting. In my experience if you know that you have enough supply power for the transceiver (in my case it even works with 100 mA 3.3V regulators) you can set the power "MAX" without a problem. In my case it increased the range a little bit and did not decrease the network quality. But keep in mind that the PA version of the NRF24L01 (the version with the power amplifier and large external antenna) is using significantly more power. So I assume you need a power source that can handle approximately >200 mA or even more.

• I personally would just leave the MySensors network on its default channel. In the USA this channel is already out of the range of wifi. In Europe you theoretically could have an overlap but I personally have not experienced problems with this. IMO the problem with using lower channels is that wifi routers set to automatically search for the best channel could choose to just hop on your precious MySensors channel. Then your effors was just a waste of time and you have to manually change the firmware on every MySensors device again. If you use the MYSBootloader to flash FOTA updates, you are tied to use the default channel anyways.

--> Just to follow up on my previous post with my quality and reliability problems of the NRF24L01 transceivers: I think I was able to solve the problem as now my communication has been running flawlessly for over two days. The trick that seemed to work was to decouple the whole device from its power source input as much as possible by using an LC filter before going into the 3.3V LDO that supplies my transceivers. Previously I tried out everything to clean up the power supply AFTER the step down converter (also tried RC, LC filters, various capacitors...) but it didn't work reliably. I assume the problem with this is that some power regulators are absolutely pedantic about the ESR of their output capacitors. Playing around with various filter configurations on the output of the regulator maybe screwed up those values and caused the regulator to be unstable. Also I have no idea what I'm doing when I'm "designing" those filters, so I just randomly tried out various combinations of inductors and capacitors. So maybe this also caused more harm than good.

But now by putting the LC filter in between the output of the switching power adapter and the input of the LDO and keeping the output capacitors of the regulator exactly as specified in the data sheet, it basically solves all those problems. Basically the LDO doesn't care at all about the ESR or capacitor values at its input and also the chance that a badly designed LC filter is causing problems is much lower as the power regulator can dampen those influences afterwards.

So in my experience this configuration can solve most problems of bad communication due to dirty power supplies:

120V / 230V AC Mains --> Switching power adapter (5 - 24V DC with loads of ripple) --> LC / PI Filter (less ripple) --> linear LDO power regulator with output capacitors as specified in data sheet (clean 3.3V DC) --> NRF24L01+

[titvs]

@Mathea90 Thanks for your input. As for the wifi, im not using my router wifi network, i disabled it. My home wifi is a mesh of Ubiquiti Unifi APs managed by me... Cant remember if the channels are on auto though… :p
You also did an outstanding work with power supplies and filtering… Congratulations.

This week i received my NRF24/PA/LNA so today i began testing range issues again. Well, i have a weird problem that i dont know if you guys already came across: since it is the amplified version, ive bought a dedicated power converter, something like this:

https://www.aliexpress.com/item/AC-DC-110V-220V-to-3-3V-700mA-2-3W-Switching-Switch-Power-Supply-Buck-Converter/32829974349.html?spm=a2g0s.9042311.0.0.31d54c4dAQgWxY

Ive tested it and its giving a constant voltage of 3.38v. I've connected it to the NRF24/PA/LNA (+ and ground) but the gateway (an Arduino UNO powered via USB) gave me an initialization error:

0;255;3;0;9;0 MCO:BGN:INIT GW,CP=RNNGA---,VER=2.3.0
0;255;3;0;9;4 TSM:INIT
0;255;3;0;9;6 TSF:WUR:MS=0
0;255;3;0;9;14 !TSM:INIT:TSP FAIL
0;255;3;0;9;17 TSM:FAIL:CNT=1
0;255;3;0;9;19 TSM:FAIL:DIS
0;255;3;0;9;22 TSF:TDI:TSL

I've then connected the radio to the 3.3v and ground pins on the UNO and it works! What am i missing here?
For the time being the gateway is working ok but its being powered via USB (altough its a 3.0 port). Anyone tried this little modules before? It would suck if i discover i cant use it with the NRF24/PA/LNA...

As for the range, im now getting good connection to a node that needed a repeater in between without the NRF24/PA/LNA so, so far so good. ;)

[Yveaux]

@titvs did you connect your power supply ground to your arduino ground?

[titvs]

@yveaux well, i thought about that. a ground problem. But since the Arduino is powered via USB (+5V), should i also connect the ground from the 3.3v power supply to a ground pin on the arduino? how about the ground pin of the NRF24?
Thanks

[Yveaux]

@titvs all grounds should be connected together, or you won't have a defined '0' level in your setup.

[aramko aramko]

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