NRF24L01+ working irregulary

[Fred Lamer]

Hi everyone,

I bought two NRF24L01+ off ebay a couple of week ago and started to work on them this week. I seem to have problem with establishing a reliable communication between both devices. I enabled Shockburst by setting register EN_AA all to "1" and register EN_RXADDR all to "1". I should then have auto-acknowledgement on the TX device. Both device work with the IRQ pin with external interrupt on my two MCU (ATMEGA8) and interrupt are masked with the STATUS register to show what interrupt is trigerred by the NRF. I seem to have a bad communication, but the packet still cross from the TX to the RX irregularly. I checked the value of the received packet and it is the same as the one sent., but no acknowledge received in the TX device...

Any fast thoughts on why it would do this?

Thanks, Fred

[Ivo Milev]

Hi Hakon,

I completely understand that , but I am talking about for completely different issue:

I have a problem when the PRX device initiate transmit sequence to some of the PTX devices. Then the firmware for PRX should set manually its TX_ADDR reg. There is no way the HW to predict to which PTX device PRX wants to talk.

In simple words:

PRX wants to say "Hello" to PTX3. And PTX3 recieves the msg "Hello" from the PRX, but does not return an acknowledge to PRX. That's my issue

Best Regards, Ivo Milev

[Håkon Alseth]

Hi,

I think I understand. You want to send data from PRX to PTX. What you can do is to send a payload with the ACK using the command "W_ACK_PAYLOAD". You need to set the registers posted here to enable that command: https://devzone.nordicsemi.com/index.php/nrf24l01-dynamic-payload-configuration-without-ack#reply-4890

Note that this is only triggered when the PRX receives a packet on the same PIPE that the PRX uploaded it to. Ex: PRX uploads 10 bytes to the FIFO on PIPE1 PRX receives a packet on PIPE0, empty ACK is sent PRX receives a packet on PIPE1, ACK + 10 byte payload is sent.

You can read more about this in the nRF24L01+ datasheet (chapter 7.8.5 and the register map).

Best regards Håkon