i have a pixhawk 4 and pi 4b setup. from what i read here with this setup i should be able to connect servos to the 1st, 2nd, and 3rd fmu pwm out pins on my pixhawk. however, i can only control the servo that is connected to the 1st pin. pins 2 and 3 send no signal whatsoever. when i try to send a command to pin 2, i get the error “Info: ServoRelayEvent: Channel 10 is already in use”. also like i mentioned in the title, the 1st pin makes the servo run at max while it boots until i send a comand to it in q ground control so the servo closes the gripper but continues applying force, which could break the gears of my servo or overheat it. the only way i can stop this is by unplugging the servo and waiting until qground control connects and then sending a command to the servo which makes it start to work normally.
Hi @bobo -
See this page for a list of how to set the servo function for normal behavior for each channel. With ArduSub, you’ll want to set the Servo#_Function to what is listed in that table for “SERVO#_FUNCTION Parameter.”
You can adjust the appropriate Servo#_TRIM to change the signal that will be sent after startup, if it doesn’t match what you prefer.