ANT Forum

Hello,
I am working on a project, which involves a batterie powered sensor with ANT+ chipset to communicate with the host unit, which is intended to display the sensor value (so somhow a standard application like Garmin <> heart rate sensor unit).

The sensor unit should only operate when the host unit is preset/activated in order to conserve batt-energy of the sensor unit. So I would like the sensor unit to go in a sleep-mode, if no host-unit is present/active.

Is there a way to activate the sensor-unit by the host-unit? Is that supported by the ANT+ and if yes, where do I find this in the docs?

Thank you a lot for your support.
Regards,
ChrisB)      

Hi Chris,

Unfortunately, there is not anything in the "ANT Message Protocol" to implement what you have suggested. Therefore, you would have to implement what you desire in your application.      

One of the difficulties with what you want is that at least one of the devices needs to be listening and radio receive is expensive in terms of current draw. If your host can handle it, you could try setting it up to search for sensors, then have sensor transmit a beacon periodically - say a few seconds every 20 - that the host would reply to when present thus letting the transmitter know to establish communication.