NRF24L01+PA+LNA wiring question

  • Hi there,
    I just received 2 NRF24L01+PA+LNA from the ebay shop linked on the store page and I am not sure if I connected them false or they are both broken.
    I understand, that they need a stable power source with 3.3V which I provided. I connected GND and VCC to the external power supply making sure it has enough juice and all other pins according to the radio wiring guide. All data sheets I found state, that the wiring is identical to the NRF24L01+

    So did I win the lottery and received two faulty examples?

    When connecting them and powering up my node, I do not see anything in the serial monitor - as soon as the standard radio without external antenna is attached, it works.
    I am lost...


  • Hero Member

    Just a guess: Are GND from the NRF24L01+ and the Arduino interconnected? Did you use the external supply together with the standard radio too?

  • @TimO
    Thank you, yes I powered it completely via breadboard and the only power came via external supply during one of the tests.

  • Hero Member

    Strange! Sounds to me, the arduino is not starting up, if the NRF24L01+PA+LNA is connected. Maybe there is a bypass between VCC and GND? Did you check the voltage on VCC?

    The wiring between those radio modules is indeed identical.

  • Hi, did you try to use standard NRF24 with the same wiring? That is the shortest way to check are they faulty or your wiring is not so good.

  • @marekd @TimO
    yes, exactly same wiring. But works now!

    So to summarize:
    the +PA+LNA pin layout is similar, it seems quite picky in power requirements, so using external stable power is mandatory!
    After adding a capacitor AND changing the Arduino to a Nano it got to life. I do not know what the problem with that UNO was I 've been testing for hours but after changing it, all good now.

    Thank you all for your help.


  • @parachutesj

    After adding a capacitor AND changing the Arduino to a Nano it got to life.

    Maybe it didn't liked the signals from the UNO. 😛 You would maybe see something on a oszi but it's probably not worth the hassle. 🙂
    Other guess: 5V Uno 3.3V nano?

    There are also many topics on this forum how to get the PA/LNA module in a working state, can be quite tricky and frustrating.

  • @Oitzu
    I don't have any measurement equipment at hand or qualifications to use it so all trial and error 😞

    But power of the two shouldn't make any differences - I always connected external power as I have been warned and stepped it down to 3.3V.

    Anyhow, as much information we collect, the easier it will become for others to learn

  • @parachutesj
    I'm using it at Nano (serial gateway), with power supply from Nano - and works just fine - no problem whatsoever. No extra caps.
    Have one UNO and will make some test later and tell you how it works.

  • OK, so I made quick tests with my UNO, just replace standard NRF model with PA/LNA and works OK. Maximum current draw was around 62 mA (with standard MySensors setting for NRF) so there should be no current problem. Power supply for UNO is standard Sony phone charger .85A 5V. There are 2 sensors connected to this UNO (DS18b20 and RTC3231SN).

  • @marekd
    thank you for your efforts. Maybe I got cheep ones... where did you order your radios?

  • @marekd
    got mine from the same seller - strange. I will try later with an original UNO and see how this goes.

  • @parachutesj
    Couple of things - get yourself a cheap multimeter. Indispensable and pretty important piece of kit when you are doing this kind of stuff, will save you frying stuff and help with trouble shooting.
    The PA+LNA version needs around 120 milli amps at peak power (from memory) some of the duinos cant supply this.
    And use the caps as suggested in the wiring guide for the NRF modules on this site.

  • @Matt
    Thanks for that. Will follow your advise.

    Actually I tested the radio with a few other Arduinos and all work except the one which I used in original post. So I guess this is faulty and already trashed.


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