This page is based on This RCGroups Post
See also this other RCG post.
The quad should have telemetry enabled by default
Devo 7e and other versions update info:
The telemetry is present in deviation firmware in the latest nightlies, currently. That means you may need to flash a recent nightly ( dec 2016 or newer) to make use of telemetry with the bayang protocol, and your flashed quadcopter.
Please back-up the model files, and perhaps other files just in case, when upgrading the transmitter firmware.
To enable telemetry , hit enter when selecting bayang protocol, the same as enabling telemetry for other protocols, such as DSMX
The protocol with telemetry enabled will only bind to a quad with telemetry capability. With telemetry off, it will bind to all quads, including factory firmware, and telemetry quads.
Telemetry data:
The quad sends battery voltage, battery voltage- compensated against throttle , packets received ( reception quality indicator ) , and battery low -led flash signal
Additionally, the tx generates telemetry reception stats.
Telemetry names:
Telemetry names are shared with the dsm2 protocol, and as such, their names are not very appropriate to describe the quantity they represent.
*Fades_L - led battery low flashing= 100 , otherwise 0
*Loss - TX's telemetry reception quality indicator in packets per seconds (max 200)
*Holds - quad's reception indicator in packets per seconds (max 200 )
*RxV -Volt1- real battery voltage
*Batt -Volt2- compensated battery voltage
Alarms: Some alarms could be setup for telemetry data. Make sure to fly in range of telemetry if you rely on them only. Telemetry range is smaller than the range of a tx with a PA module.
FadesL > 1 will create an alarm that sounds if the leds flash a low battery code
Batt ⇐ 3.40 is ok for low battery alarm - using voltage compensation settings from config.h
Rxv ⇐ 2.90 - real battery voltage - this would be more like a traditional lvc that sounds on max throttle sometimes
The real voltage goes down a lot, so it may not be very useful. An alarm of 2.8 - 3.0 could be used.
Additional:
Since the telemetry range is shorter compared to the tx range ( with PA ) , there is no point setting an alarm for quad reception strenght, as the telemetry will probably fail before that level is reached.
The quadcopter only sends telemetry after a packet is received from the transmitter. This is to avoid on-air clashes when the code hopping becomes unsyncronized. Because of this, the telemetry rate will go down when reception is poor on the quadcopter.
HACKs: