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Topic: NRF24L01 pa+lna can recieve data but failed to sent anything (Read 208 times) previous topic - next topic

cowboyyyy

I  sent a hello world with NRF24l01 module.

Everything is fine with little modul but with the antenna  one, there is this problem,
I bought 4 of them so I changed every one so I dont think it is from the NRF module.
NRF24L01 pa lna can recieve data. But it failed in senting.
what the hell is going on?
I dont think it is a power suply issue or noise issue.Because if it is the case.NRF24L01 pa lna could
send something when they are very closed or touched by me.I try a battery power supply oradding a capacitor. But nothing worked.

Robin2

I strongly suspect the high-power module is not adequately powered. At least for testing try powering it with a pair of AA alkaline cells (3v) with the battery GND connected to the Arduino GND.

...R
Simple nRF24L01+ Tutorial
Two or three hours spent thinking and reading documentation solves most programming problems.

frapell

I strongly suspect the high-power module is not adequately powered. At least for testing try powering it with a pair of AA alkaline cells (3v) with the battery GND connected to the Arduino GND.

...R
Simple nRF24L01+ Tutorial

I am having this *exact* same issue...

having 2 nrf24l01 with internal antennas, they can send and receive data just fine between them.... as soon as I replace 1 of the modules with a PA-LNA version (with the external antenna), I can send data 1 way, from the low-powered -> PA-LNA, but not the other way around...

This is pretty much the same as this other topic too https://forum.arduino.cc/index.php?topic=571966.0


I have tried with external power with no luck... I have tried with a 3.7v (18650 cell), as well with a dedicated PSU...

Just to be sure, I am connecting the vcc from the nrf24l01 module to the positive of the battery, and the gnd both to the Arduino GND, as well as the battery negative... Also, I have a 10 µF capacitor between VCC and GND...

Am I missing something?

Robin2

I don't have any personal experience with the high-power nRF24 modules.

A fully charged LiPo will be at 4.2v which is too high for an nRF24 - their max is 3.6v. However a LiPo should certainly be able to provide enough current.

I believe there can be problems when a high-power module is to close to another module - the signal is too strong. Try again with a distance of about 3 metres between them.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

frapell

I believe there can be problems when a high-power module is to close to another module - the signal is too strong. Try again with a distance of about 3 metres between them.
Yup... I have tried all possible distances, from very close, to 2, 3, 4 meters away... walls in between, 10 meters away... nothing... the PA-LNA keeps receiving the pings, but the response won't go from the PA-LNA to the low-power module.

I even tried 2 PA-LNA, one on each Arduino... Nothing is going on, since neither would send anything :(

Robin2

Nothing is going on, since neither would send anything
You need to be careful here. You can't actually tell whether the problem is with the Tx or the Rx.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

frapell

You need to be careful here. You can't actually tell whether the problem is with the Tx or the Rx.

...R
Well, I've done quite extensive testing with a lot of combinations and everything seems to suggest that the issue is with sending. I'm trying the basic example that would send a value, and if it receives a valid response, it will add 1 to the variable and send it again, so you can figure out if the whole communication is going in both ways:

1)

nrf24l01   <->    nrf24l01

This scenario works just fine... one side sends, the other receives, responds, and the loop goes on fine

2)

nrf24l01   <->    nrf24l01-pa-lna

one side sends, the pa-lna receives, but fails to send anything back


3)

nrf24l01-pa-lna   <->    nrf24l01

Nothing happens, there is no initial packet being sent


4)

nrf24l01-pa-lna   <->    nrf24l01-pa-lna

Nothing happens, there is no initial packet being sent


Finally, when trying a "scanner" example from the library, all modules would pick up noise on some channels...

To me, it is pretty clear that there is an issue with sending from the nrf24l01-pa-lna modules...

I have found this guy, experiencing the exact same thing, with a rpi, not arduino, but still... https://forum.mysensors.org/topic/6273/nrf24l01-pa-lna-msg-send-failure

Now, it may be a power issue... but I am unable to figure it out...

Robin2

To me, it is pretty clear that there is an issue with sending from the nrf24l01-pa-lna modules...
I understand what has brought you to that conclusion but all you actually know is that communication does not work when the high-power module is transmitting.


Can you get another module (preferrably from a different supplier) and see if it works?

...R

Two or three hours spent thinking and reading documentation solves most programming problems.

frapell

Can you get another module (preferrably from a different supplier) and see if it works?

...R
Yup, I have 2 extra ones I bought from a different supplier (total 3 modules with external antenna). They all behave the exact same way :(

frapell

Also, don't get me wrong... I am pretty sure there's something I'm missing, however I do not know what else to try...

I've tried different capacitors between vcc and gnd
I've tried the Arduino 3.3v out
I've tried a LiPo battery
I've tried an external PSU at precisely 3.3v
I've tried close range, as well as far away, both with and without walls in between


The non PA-LNA modules work just fine... the PA-LNA modules do receive data... they won't transmit anything back...

Robin2

In this situation
Quote
nrf24l01   <->    nrf24l01-pa-lna

one side sends, the pa-lna receives, but fails to send anything back
is the pa-lna correctly sending an acknowledgement?


Have you tried powering the nrF24 with a pair of fresh AA alkaline cells (3v)?

I can't think of anything else to suggest.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

frapell

Nope... data is properly received by the module, but it won't send an ACK back, and it won't send anything when I try .write()

I have not tried with two AA bateries... I have none at the moment... I will buy some and give it a try...

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