ANT Forum

I'm working on a sensor uses an ANTC7_Ver1 module that transmits at 20Hz. The host sends commands to the sensor in the reverse direction. I originally wrote my host on the PC and everything worked fine.

I wrote a similar host app for the iPad using thr Wahoo dongle. My app runs fine for a few minutes and then communication in the reverse direction fails and won't start working again until I restart my app. Restarting the app or using the PC version of the hosts works, so I do not believe the issues is on the sensor side.

I am still receiving messages in the app, and every 6th message I send a message in the reverse direction. I do not see any error messages. Is there a reason all reverse channel messages would start failing? It seems most likely that they will begin to fail after a burst message from the sensor to the host.

Any ideas?      

Was the channel assigned by any chance as Rx only? Sounds unlikely, as you mention you had the configuration working on a PC before, but may be worth double checking.

Is the message you are sending on the reverse direction broadcast or ack? Do you ever get other messages (EVENT_TX) after sending the reverse direction data message?

What kind of serial connection are you using between the module and your MCU? Is the module mounted on a PCB, or is it fly wired to the rest of the circuit?

     

I've setup ANTware II to monitor the communications using Scan Mode. I'm pretty sure the issue is on the iPad end, since I can see the return messages and then they just stop. I'm not opening the channel in Rx only since it works initially. But I'm wondering if the Wahoo API is filtering out my return messages or is setting the channel to Rx Only or changing the Tx power behind my back. The Wahoo API doesn't get full access to the ANT chip in the dongle (ie you can't change network 0), I'm wondering if there are other limitations I'm running into.

The reverse direction is broadcast.

Edit:
When the reverse communications is working, I receive EVENT_TX. Once it stops working, I no longer receive EVENT_TX. But I don't receive any error messages either. It seems the message is getting lost somewhere between my App and the ANT hardware in the dongle.      

Investigating further, I no longer believe it has anything to do with reverse messages. It's the Wahoo API that is failing. Any message I send to the dongle at too high a rate causes all further calls to [WFHardwareConnector sendAntMessage] to silently fail.

I assume this is a widely used function, so I don't see how it can be broken without a lot of people noticing. I assume I'm doing something somewhere else that causes the problem. Does anybody have experience with the Wahoo API that can chime in? Or does Wahoo offer any support for their API?      

Thanks for the additional information. It does sound like problems in the serial communication with the dongle. You should probably contact Wahoo directly for support with their API .      

Who wouldn't happen to have a technical contact a Wahoo would you? They don't seem to offer any support on their website.