Hi guys. I'd like to homologate the info about setting up motor RPM count into the Pixhawk. There is a bunch of stuff above in old posts but it's slightly ambiguous and is spread out now.
So to read RPM on mission planner (and to log to dataflash I hope also) we would connect a RPM pulse signal to AUX OUT 5 signal pin, we set RELAY_PIN to -1 to make sure that pin is not used for relay trigger, we set BRD_PWM_COUNT to 4, set RPM_TYPE to 1 leaving the other RPM parameters alone. We add the RPM1 display to the Mission Planner status view. And it should work...
Is that all correct?
If so I'm not reading RPM yet on MP. My pulse source is from a brushless RPM sensor module and gives me a 116.6Hz per 1000rpm out square wave (on a 14 pole motor). On my CRO the signal is reasonably clean.
In the older posts it's not 100% clear to me if the Pixhawk is expecting a scaled PWM signal of variable duty cycle like a servo signal, or if it's expecting pulses at a frequency proportional to the RPM, like I'm giving it.
Anybody confirm which is definitely right ?