nRF24L01 with Antena issues - to close issue?


Been searching google and this forum. Found some info but that still didn't helped me with same problem that other have.

My problem is that i can't for some reason force 2 arduinos (UNO & MICRO) to communicate with each other using RF24L01 PA-LNA module in each arduino. All works great with RF24 without antena.

  1. Code that i'm using is from example for testing. I had to go to basics for troubleshooting.
  2. I use MIN power as they are quite close to each other (0,5m or in the room tops 5m)
  3. I use on board power 3.3v but been trying with polou 3.3 step down and 9V battery for tests.
  4. Had to add 470uF capacitors for 3.3v to ensure that modules will have sufficent peak power capacity to power antennas.
  5. Measured 8mA while transmitting data. My guess it can even consume more. So nothing big that arduino can't handle.

I don't care about data rate as i will be sending like few bytes of data every 1min on like 70m distance in open air. Unfortunately RF24 w/o antenna is working with maximum distance 50m. My original code and example code delivered with library works on max 50m with these modules without PA-LNA and with MAX power set for transmitting and receiving. I need more power, so i got similar modules with antenas and they don't work... :confused:

I've noticed something when i use 1 modules w/o PA-LNA and 1 with PA-LNA on example code. If i setup arduino + module w/o PA-LNA then arduino with PA-LNA see the messages, but either don't send it or this one with PA-LNA is not able to read the message - i get "time out". This way somewhat I confirmed that module with antena is, somewhat, working. When i use only modules with PA-LNA then it completely stop working. Nothing is being recived or sent. However. Been playing with some shielding on MICRO with PA-LNA and antena layout with the other module (arduino Uno + PA-LNA module) like 5m away without shielding and sometimes it worked.

Is this related to too strong signal?

I though that when using MIN power on like 5m away i should get anything. Isn't it?
Strange that whenever i played or hold antena in hands it sometimes worked. But that drives me to point that 5m is too short distance and signal is too strong. But when i take out antenats it still don't work.

In summary:

  1. 2 arduinos with 2 24L01 PA-LNA modules
  2. 470uF capacitors in 3.3v on board power added and from there i take power (been also trying from step down 3.3 power unit pulling down from 9V battery). Capacity definitely help with these w/o antenna
  3. distance 5m in house between modules
  4. example code from 24 lib for tests

with modules w/o PA-LNA works, but changing them to those with PA-LNA it does not.

Any idea?

Try first with 2 ordinary (NOT PA/LNA) boards.

Get good quality boards and not the cheapest ‘fakes’ off of .