Leonardo does not work with RF24 module

Hi there,
I am trying to transmit data from a Nano to a Leonardo using RF24modules.
When using the Nano as the transmitter and an UNO as receiver, every thing works well.
However, when moving the pins from the Uno to the Leonardo using the same sketch, it does not work anymore.
I need the Leonardo in my project because I need to use the Keyboard capabilities.
The ISCP headers are used on both, the Uno and Leonardo.

I have read multiple threads on the forum which cover this issue but it did not give me a solution for the problem.

Any idea's??

Have you got anything else connected to the Leo ? If so, what and which pins does it/they use ?

Have you tried connecting the RF24 module to the corresponding pins along the edge of the Leo instead of the pins on the ICSP header ?

Hi Bob,
nothing else is connected. Only the RF24 module.
And yes, I did try to use the following pin configuration:
pin 7 (CE)
pin 8 (CSN)
pin 11 (MOSI)
pin 12(MISO)
pin 13 (SCK)
the modules are always connected to 3.3v and I also use a capacitor between the 3.3v and GND

the CE and CSN are set in the RF24 object . I also tried pins 9, 8 and 8, 10 as a possible solution mentioned in some threads.

Because it works fine using the UNO but not with the Leo, it must have something to do with the Leo board itself.
To rule out a possible defect in the Leo, I tried a second Leo: same problem.

I hope you can help

The SPI pins, which the NRF24L01 needs, are available only on the Leonardo's six pin ICSP header. See: Arduino Compatible Leonardo - Funduino brand (HCARDU0050) - forum.hobbycomponents.com

1 Like

thanx for your reply 6v6gt.
I am using the SPI pins on the ICSP header. But even then, it is not working.
Using the exact same pin's on the Uno does work.

I would suggest powering the radio module on the Leonardo with an external supply like a 2 AA series cell (3V) battery pack in case the 3.3V regulator on the Leonardo cannot supply sufficient current (even with the cap). Lack of sufficient power is, in my experience, the number one reason for failure.

You hit the nail on head.
Connected the RF module to an external pSU and voila.
Every thing is working well with the Leonardo.

Many thanks for your help

This from the spec of the Leonardo link in post #4 :

DC Current for 3.3V Pin: 50 mA

That is not enough for the NRF24L01 as you have now demonstrated.

Please mark the thread as solved so that other members that wish to help will not waste their time opening the thread only to find it solved.

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