ANT Forum

My Bike Power protocol sensor CPU sends the configuration packets (network key, channel assign, channel ident, radio freq, channel period) and receives the RTS pulse and a reply packet from each. Then the CPU sends the open-channel packet (0x4B) and gets the RTS pulse, but about 10% of the time, the CPU does not receive the reply packet. With no channel open on the sensor, the ANT+ Display Simulator times out in its search for a device to pair. If the CPU repeats the send of the open-channel packet, all is well.

Most likely, of course, is that my code is at fault, but I have a few questions to help me debug.
1 - Is a 10% failure rate to be expected? All other packet types are acknowledged 100% of the time.
2 - How long should my code wait for an acknowledgement before resending?
3 - After the channel-open packet is sent from CPU to ANT successfully, is the acknowledgment packet from ANT to CPU guaranteed to arrive before the first EVENT_TX packet?
4 - What is the minimum time between the completion of the open-channel send and the first radio transmission?

Thanks.      

Is your serial communication functional after this? Are you able to get other messages through successfully?

You should be getting a response back to the open channel message, either a successful one (RESPONSE_NO_ERROR), or something indicating why it did not succeed. If you are not getting anything back, this would seem like there is a problem with the serial communication, or some other hardware issue.

Could you please post traces of the serial lines (Rx, Tx, RTS, SLEEP) during your channel configuration sequence, and particularly after sending the open channel message? Any activity on RTS after it toggles after the last message is received?