nRF24L01's not communicating

I’m following Robin2’s tutorial for nrf24l01 module(Simple nRF24L01+ 2.4GHz transceiver demo). No matter what i do two modules won’t communicate. I tried running this code (Simple nRF24L01+ 2.4GHz transceiver demo - #30 by Robin2) and it seems like my modules are working fine. I’m using normal 23cm jumper wires they are bit long is this the problem? Also when i touch the antenna part of the nrf module it seems like module is transmitting some trash. One other thing is that i use LM2596 dc-dc to regulate 5v from a phone adapter to 3.3v to feed the nrf module. Modules are 6cm apart from each other.

Hi,
Welcome to the forum.

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Can you post a picture of your project so we can see your component layout.
Can you post a link to the NRF modules you have? There are many different units.

Have you got 10uF capacitors on the 3V3 to gnd at the NRF units?

Thanks… Tom… :grinning: :+1: :coffee: :australia:

Hello, Here is a picture of the circuit

nRF24L01 module datasheet : NRF24L01 datasheet(39/39 Pages) ETC1 | Single chip 2.4 GHz Transceiver

LM2596 Adjustable DC-DC Converter Buy LM2596 Adjustable Voltage Step Down Power Module (4-35V Input - 1-30V Output) at an affordable price - Direnc.net®

Here is another picture of the circuit

Note: I unplugged one of the nRF modules on purpose

Hi,
You have 5V for the ProMini connected to Vraw.
You should have 5V connected to Vcc/5V pin.
Vraw supplies a 5V regulator input.

Tom… :grinning: :+1: :coffee: :australia:

A few things:

  1. Did you try Robins module communication test sketch? - it’s towards the end of his tutorials.
  2. The radio modules are pretty close together. I would suggest lowering the transmit power level whilst you are experimenting with them in close proximity like that.
  3. Do you have and male-female jumpers so you can connect directly between the radios and the Arduinos? Breadboards can be a real pain with poor connections.

I tried changing Raw to Vcc nothing has changed. I still get SimpleRX starting in Serial Port and nothing else.

  1. I tried the sketch which makes you see whether the module is connected to arduino or not. I will try the one you just said in a few minutes and give feedback
  2. How do i lower transmit power? By simply lowering the vcc to something lower then 3.3v ?
  3. Yes i can do that, Will give you feedback in a few minutes.

Tried connecting them with m-f jumpers it didnt work.

To reduce the RF power when transmitting, add the following line to the end of the setup() function:

radio.setPALevel( RF24_PA_MIN );

That should set the lowest transmit power level. I’ve not used nRF24L01’s that close to each other before so I don’t know if even that RF power setting will be too high. You could try separating the 2 radios by 2 or 3 feet to see if that helps.

Thanks will do that in a few mins.

5 Days after i said “i will do that in a few mins”… I tried it, still no luck.

I just noticed that my nRF module is drawing 2 amps of current is this possibe?

Hi,

Ahh no!!!
Have you got a short at the NRF pins?

Tom… :grinning: :+1: :coffee: :australia:

Hi,
I assume you have made an adapter board under the NRF to allow it to sit across the gap in the middle of the protoboard?

Tom… :grinning: :+1: :coffee: :australia:

Yes i did make an adapter board. I just tested the module nothing seems to be shorted. Other nRF module which is powered by arduino uno is drawing 0.2Amps of current.

Do you think the module is fried?

I think it’s safe to assume that if your nRF24L01 module is drawing 200mA when idle, then something is not right with your setup. What current draw do you get when you apply just the GND & +3.3V with no other wires connected?

with only GND and 3.3V connected it draws 0.22amps of current. I tried it with all 3 modules i have and all of them are drawing 0.22 amps when connected to arduinos 3.3v. They all draw 2amps when connected to buck converter. Also lights on arduino gets dimmer when i touch positive and negative terminals of nrf module with the multimeter’s probes

You are aware that you have to measure current differently from measuring voltage?
You sound as if you were shorting the 3.3V supply with the amp meter.