Is there a way to utilize custom sensors that APM does not support?
Either directly or indirectly, I need a way to know what the health of a gas engine (temperature, RPM, etc).
Here are some possible ways I can think of.
1) Interface Arduino with Pixhawk. Use Arduino with widely available temperature and RPM sensors to read the values and transmit to Pixhawk. The problem is that Mission Planner doesn't display these values on the Flight Data screen.
2) Arduino have seperate radio system transmitting engine data. Not good since it means having an extra set of radios which increases battery consumption.
3) On board LED display for Arduino sensor readings Asides from FPV and gimbal cameras, I could have a smaller, low power camera connected to the Pixhawk that captures the readings from the LED display. Ain't pretty.
4) The hard way. Develop new APM code to read values from sensors I need and develop Mission Planner code to display those values somehow. My coding skills are no where near the level of being able to do that so this is a no.
I am in a similar situation as you, what did you decide? My current plan (quick fix) is to just use an existing mavlink message to send my data to the GroundStation and display my custom sensor data as some other existing value in the "Value Widget Setup" in QGC. Downside is that the label will be incorrect, but it is a quick solution.