NRF24L01 and arduino

Using Arduino Networking, Protocols, and Devices
1

Hello,

I am trying to exchange data between 2 Atmega328P through NRF24L01.

  1. Library and Sketch
    I use the Tmh20 library here . And use the getting started sketch to start RF24/examples/GettingStarted at master · nRF24/RF24 · GitHub .

I send to the first arduino witht the code bool radioNumber = 0;
and the second bool radioNumber = 1;

But i am getting nothing ( just 5 weird character on the Serial console).

  1. Schema and electronic

This the schema of what i did on breadboard

This is a picture of my breadboard

Also i plug
CE -> D7
CSN -> D8
SCK -> D13
MOSI ->D11
MISO ->D12

I add a 10 micro farad capacitor between the GND and VCC of the NRF24L01.

My voltage supply come from a power generator ( current consomption is 0.6 A for the two arduino with 2 NRF24L01 ). The power supply provide 5 V and i derive 3.3 V using an LM3940 using the first schema (simplied ) on the datasheet here

  1. Symptom

Nothing appear on the Serial console except 5 weird characters.I can't see any light for activity on the NRF24 module.

If anyone have an idea about i could debug that thing ?

All the best

Vincent

2

Sorry the image does not appear,

The schema and the photo of the breadboard

3

How are you bringing the 328P 5V IO signals down to 3.3V levels for the nrf24L01s?

4

The NRF24L01+ have 5V tolerant I/O pins.

5

You do not have the RF24 signals connected to the correct pins on the 328. Leave Int(8) unconnected and move MOSI to the right pin, not an interrupt.

6

Hi thanks for your answer,

@CrossRoad i don't bring down the 5v to 3.3v on the signal ( only for power ) , i didn't knew i have to do that. Should i do it ?

@Artic_Eddie, Thanks however i am not sure to understand which pin i should plug there, sorry to ask you to reformulate.

All the best

Vincent

7

I got my nRF24s working with this Tutorial.

...R

8

Use the connection chart in the link that Robin2 gave. Use the column labeled "Arduino pin for
RF24 Library". Do not connect the interrupt pin(8) as the library does not use it. I used ManiacBug library but recently switched to TMRh20. They both work with the examples. You need the 3v3 supply only for RF24 power. The signal pins are 5v tolerant. There is an adapter board on eBay that has the regulator and filters with signals on header pins. This solves the power problem by taking the load off of the Arduino regulator.

9

Arctic_Eddie:
There is an adapter board on eBay that has the regulator and filters with signals on header pins. This solves the power problem by taking the load off of the Arduino regulator.

This is a good idea.

However I have had no problems powering my nRF24s from the 3.3v pin on my Uno or Mega.

Another option (which I have used with an ESP8266) is to use a LM317 voltage regulator to produce 3.3v from the Arduino 5v pin. However the eBay product is probably more convenient.

...R

10

The low power version of the RF24 will work OK using the Arduino 3v3 output. However, on some occasions the physical wiring layout, lead inductance, requires a capacitor to handle the TX current spike. The high power version, nRF24L01+LNA+PA, pulls too much current from the on-board regulator. An external 3v3 regulator will be needed. Also, the RF24 board cannot be plugged directly into a proto board and must use dangling wires or a homemade adapter. The eBay adapter board is a nice addition as it solves all problems for both the low and high powered versions.