ANT Forum

I've converted the demo code to run using async uart interface and am having trouble getting an ANT-FS session to run properly. I have observed some odd behaviour that seems to be related to Tx queue. Specifically, with default queue size (2), the directory request from PC host would fail during directory download. Using Logic logic analyzer, and PC logs, the burst of directory failed at same spot. When I increased queue size, the failure changed to directory download rejected although at a different, later spot in the burst. In both cases, while the final burst packet appeared to be being placed in the queue, it was never transmitted.

Any suggestions on possible cause or what to try?      

Additional testing results.

Increasing buffer size to 16 allowed directory download but file downloads failed.

Increase buffer size to 32 allowed directory download and smallest demo file but that's all.      

Since failures are consistent, and related to the Tx buffer size, I would suspect that this may be related to timing of the serial burst packet transmissions. What size bursts are you sending? At which point in the burst did the transmission fail for the queue sizes that you have tried? Are you able to provide the traces from the logic analyzer?