Does anyone know if they will work?
I’m thinking something like this:
https://www.helidirect.com/helicopters/electronics/governors-rpm/rpm-sensor.html
Along with this:
http://ardupilot.org/copter/docs/parameters.html#rpm-parameters
Jakob, those sensors are made for the eLogger (Eagle Tree electronics). I think they put out a PWM signal, but you could contact Eagle Tree and ask.
I use magnetic pickup sensors myself on both the piston and electric, with telemetry to the radio for headspeed. I prefer the magnetic because if the engine or motor quits in flight the alarm on the radio goes off at 50 rpm below normal headspeed, which is nice for autorotations. And when “fun flying” without the ground station still have headspeed on the radio display. I drill a hole in the autorotation gear and glue the magnet into the hole and make a little bracket to hold the magnetic pickup sensor.
Most modern RC radios support some type of telemetry with the proper modules and/or sensors.
I’m running UHF/OpenLRS and while telemetry is feasible, I get it all via the pixhawk telemetry and would prefer to keep it that way.
I guess it’s worth contacting Eagle Tree and ask what they’re PWM values refer to, but I suspect they wouldn’t be keen on answering that.
Alternatively get both and I could at least calibrate the Eagle Tree output against the magnetic sensor.
I played with one of those before (on a eLogger) and there’s a software application for it that you calibrate it with. I’m pretty sure it’s standard PWM output, and therefore should work for Pixhawk, just set the param for the sensor to PWM.