ESB repeat ACK payload

[Steve H]

Hi,

I haven't been able to find a clear answer to this.

With the ESB protocol, a payload can be stored in the PRX TX FIFO to be sent back to the PTX as part of the ACK. The way I read the documentation, that payload is then assumed to have arrived and is removed from the PRX TX FIFO.

If the PTX doesn't receive the ACK, and retransmits its original packet, does the PRX remember that it sent a payload with its original ACK packet, and retransmit it?

Hope that's clear and that I haven't missed something obvious in the docs.

Thanks.

[Kenneth]

Hi, There is a PID (packet identifier) field in all packets, so the ESB protocol ensure that an ACK packet from the PRX is sent (and retransmitted) until the PID is updated from the PTX (indicating a new packet, and not a retransmit).

[Steve H]

Thanks, Kenneth. Does the retransmitted ACK packet include the payload each time? The documentation seemed to suggest that the payload was deleted from the PRX FIFO with the first ACK transmission.

[Kenneth]

Each time yes.

[Steve H]

Thanks, Kenneth, I'm clear about it now.