Now that I have a proper working test tool for send/receive messages from to ST16 (or ST10, 24) I can check the reactions of the ST16 on different values in telemetry.
Independent from vehicle type the reactions on error flags in byte 38:
Error flags | 0000 0001 | Aircraft Battery Voltage Low!\nAlert: Maximum Height Decreased to 60 meters / 197 feet |
| 0000 0010 | Aircraft Battery Voltage Critically Low! Land Immediately.\nAlert: Home Mode Will Land Directly Above Current Location. |
| 0000 0100 | Alert: Aircraft Unable to Fly At or Above 8,000 Feet MSL. |
| 0000 1000 | |
| 0001 0000 | Alert: Aircraft Unable to Fly At or Above 8,000 Feet MSL. |
| 0010 0000 | After 3s: Compass warning!!! - Please land in Angle Mode immediately, then do compass calibration. |
| 0100 0000 | |
| 1000 0000 | Warning No Fly Zone, please contact [email protected] and provide the following GPS Coordinates to dispute this location or suggest no fly zones. |
Edit: @Pöllö
The only important Error flags are Voltage warning level 1 and 2.
Strange: If both are set, nothing happens at ST16. It should be
either 1 or 2!
Also I found a message from ST16 depending on OBS switch. This message will be initiated when Sonar flags in IMU status and Pressure/compass status are set to 1.
header1 | header2 | len | MsgType | PL1 | PL2 | CRC8 |
55 | 55 | 04 | $14 = 20 | 05 | 00 | 10 |
55 | 55 | 04 | 14 | 05 | 01 | 17 |