Advice for simple communication from nrf51822 to nrf24l01 ?

[Cedric Honnet]

Hi everyone ! I'm trying to send data from an nrf51822 to an nrf24l01 with arduino and I guess I'm doing something wrong...

For the moment I succeeded to have these talking together:

...so I guess the hardware is not the problem :) (if you're curious about the context, the project is explained here: hackster.io/cedric/twi)

I looked for similar problems on the forum but I don't find the solution to my problem, if anyone has a suggestion I would be infinitely grateful ;D

Here is the configuration I use:

nrf51 (TX): radio_config.c main.c

nrf24 (RX) with arduino: Mirf.cpp RX.ino

I used the nrf51 sdk suggestions and an nrf24 library (+datasheets) to understand it, but it doesn't work (yet!), the nrf24 reception pipe stays empty.

Anyone has any suggestion to offer ? Thanks a lot !! ;)

[Håkon Alseth]

Hi Cedric,

The nRF51 does not have the enhanced shockburst in hardware anymore, which means that when you send a payload from the nRF51 side, and the L01+ is configured to do auto-ACKing, you will run into issues.

What I would suggest is that you use the ESB-library on the nRF51 side, and on the nRF24L-side you enable registers:

• EN_DPL for your pipes.
• EN_DYN_ACK
• EN_ACK_PAY

If you look at the ESB library documentation, there's a section on how the nRF24LE1 should be configured (see the nRFgo SDKs hal_nrf.c file for reference to the calls, its basically the registers I posted): devzone.nordicsemi.com/.../a00139.html

Best regards Håkon

[Cedric Honnet]

Thanks a lot for your answer Håkon, it works ! Cedric.

PS: you mustache rocks, but my haircut is unique, lol ;p

[Håkon Alseth]

Glad to hear it worked. I do not think anyone can replicate that great piece of hair. ;-)

[Gavin]

This is quite an important post for people trying to get NRF51822s working with legacy NRF24 systems, and solved the problems that I was having with acking. I had to modify the RF24 library I was using to set the EN_DYN_ACK register.

Is there any reading I can do to better understand why this is necessary?

[Matt]

Gavin, do you have any example code that you managed to get working with that maniacbug library for the RF24 and the nRF51 SDK? I'm trying to accomplish the same thing and having a bit of trouble.

[Gavin]

(1/3)

Apologies for the delay - been busy. The code below (spread over 3 messages) is running on a Raspberry Pi Model B with an NRF24L01 board, and an NRF51822 without softdevice.

At the RPi end, the enableAckPayload routine in maniacbug's RF24.cpp needs to be modified so that both the writeregister commands set the EN_DYN_ACK register too. ie. change from:

write_register(FEATURE,read_register(FEATURE) | _BV(EN_ACK_PAY) | _BV(EN_DPL) );

to

write_register(FEATURE,read_register(FEATURE) | _BV(EN_ACK_PAY) | _BV(EN_DPL) | _BV(EN_DYN_ACK) );