RPM Sensor on PMW - no idea how to use/connect

Hi Guys,

I am sitting on the subject for 3 -4 days now and have no idea how to solve it :

  • Pixhawk
  • PWM signal simulating signal from RMP sensor.


  • Ardupilot version 3.1.5 or
  • Ardupilot git with my own changes in the RMP_module to improve logging.
  • Missionplanner

Cable connected to AUX5 PWM.

  • always 0 RMP on the Missionplanner.
  • After add Logging in RPM_module log-file appears on the SD-card but its empty.

Tests :
After running some test on console with creating /dev/pwminput0 with pwm_imput tool and use
"pwm_imput test" - signal is read - as I try to crawl through the code I think this device is imput for RPM1
Many setups in the parameters RPM_X tried - no changes. (description of the params in the help is very thin)

Can any1 tell me what o do wrong ? - IMHO RMP for plane is one of the most important information when you are setting up the plane for particular assignment - especially on gas/glow engine.
I was trying to dig google but found almost no info,
Regards Jacek

Also interesting ho to integrate RPM sensor to the Pixhawk based system, but did not find any information. Could any one share some, how to setup hardware and software.