ANT - EVENT_RX_FAIL

[polarstate]

I am seeing some very strange behavior when using an ANT channel with the sd_ant_acknowledge_message_tx call to guarantee message deliveries between a master and slave.

The behavior I have implemented on both the master and slave is as follows:

If event->eventCode == EVENT_TRANSFER_TX_COMPLETED send a new message.

else if event->eventCode == EVENT_TRANSFER_TX_FAILED resend the same message.

This setup mostly works fine, however whenever a slave receives an EVENT_RX_FAIL, the master may receive a message other than the last message sent to the softdevice.

I have attempted to clear the pending transfer on the EVENT_RX_FAIL event, but this does not stop incorrect messages from being sent.

Has anyone had any experience with this type of error before? Any help would be appreciated.

[polarstate]

The behavior I was seeing actually was a result of a single master being connected to two different slaves over the same channel. When one slave would get an EVENT_RX_FAIL, it would have been because the other slave had successfully transmitted. This is why the master seemed to get an out of sequence message when the first slave received an EVENT_RX_FAIL.

Hope this helps anyone who stumbles across this issue in the future :)