Why am I getting no ACKs from an nRF24L01p in PRx mode?

[JimR]

Hi folks, I'm making progress with a program to get two nRF24L01p modules communicating with each other, but there are a couple of remaining problems. I hope someone can help with them, please:

1. The PTX module seems to be transmitting my 3-byte payloads correctly, and the VDD_PA pin on that nRF24L01p pulses high (~2.0V) as expected. The PRX module even reports that it is receiving most packets from the PTX module (often 6 packets in a sequence, but then there's a 'timeout' reported). BUT the PRX module never seems to be sending back an ACK, and the PTX module consequently reports that no ACK has been received. The VDD_PA pin on the PRX chip never pulses high, either -- presumably because no ACK is being sent. Can anyone suggest what I'm doing wrong?
2. I'm puzzled as to why the PRX module reports that 6 successive packets have been received successfully, but then reports a timeout with no packet received. Then it will report that the next 6 packets were received, before reporting another timeout + no packet received. And so on. This sounds a bit like some sort of timing problem, but I can't work out exactly what. Any suggestions? Thanks, JimR

[ovrebekk]

Hi Jim

Can you share the configuration settings for your PTX and PRX?
It sounds like there are some incompatibilities in the setup, based on the behavior that you describe.

Are you using any particular libraries for setting up the Nordic modules, or have you implemented everything from scratch?

Some more information on the hardware and software you are running could be interesting.

Best regards