Sending command to MAVLINK MAV_CMD_DO_SET_SERVO via MAVROS

1

Can I send the PWM values for the motors that I used for my quadrotor to MAV_CMD_DO_SET_SERVO using MAVROS? I want to be able to set the speed at which the rotors spin manually.

2

Im currently at the same point. In the documentation it is said MAV_CMD_DO_SET_SERVO is supported. Even thou I would not recommend it for rotor speed!!!

I was planning to send PWM to AUX 5 in order to control a servo but I only get:
CMD: Unexpected command 183, result 3

Did u manage to use the command via MAVROS ?

3

Here is my start up and the response. Also the /diagnostic. But I cant figure out why it does not accept my command :slight_smile:

[ INFO] [1532619055.478486720]: MAVROS started. MY ID 1.240, TARGET ID 1.1
[ WARN] [1532619055.534155215]: GP: No GPS fix
[ WARN] [1532619055.545583955]: TM: Clock skew detected (-1532594540.554190397 s). Hard syncing clocks.
[ INFO] [1532619055.611560442]: IMU: Attitude quaternion IMU detected!
[ INFO] [1532619055.612270816]: IMU: High resolution IMU detected!
[ INFO] [1532619055.749501500]: CON: Got HEARTBEAT, connected. FCU: PX4 Autopilot
[ INFO] [1532619055.847462525]: IMU: Attitude quaternion IMU detected!
[ INFO] [1532619055.848405104]: IMU: High resolution IMU detected!
[ INFO] [1532619056.758370289]: VER: 1.1: Capabilities 0x000000000000e4ef
[ INFO] [1532619056.758512267]: VER: 1.1: Flight software: 010800ff (00000000F3E3ADAE)
[ INFO] [1532619056.758640717]: VER: 1.1: Middleware software: 010800ff (00000000F3E3ADAE)
[ INFO] [1532619056.758772548]: VER: 1.1: OS software: 071600ff (0000000000000000)
[ INFO] [1532619056.758896976]: VER: 1.1: Board hardware: 00000011
[ INFO] [1532619056.759019372]: VER: 1.1: VID/PID: 26ac:0011
[ INFO] [1532619056.759104005]: VER: 1.1: UID: 3036510e36373734
[ WARN] [1532619056.759928950]: CMD: Unexpected command 520, result 0
[ INFO] [1532619065.750967546]: HP: requesting home position
[ INFO] [1532619070.755120888]: WP: mission received
[ INFO] [1532619075.750572389]: HP: requesting home position
[ WARN] [1532619085.713035388]: GP: No GPS fix
[ INFO] [1532619085.750970183]: HP: requesting home position
[ WARN] [1532619092.754518791]: CMD: Unexpected command 183, result 3
[ INFO] [1532619095.750580280]: HP: requesting home position

Mavros:
[ INFO] [1532619055.611560442]: IMU: Attitude quaternion IMU detected!
[ INFO] [1532619055.612270816]: IMU: High resolution IMU detected!
[ INFO] [1532619055.749501500]: CON: Got HEARTBEAT, connected. FCU: PX4 Autopilot
[ INFO] [1532619055.847462525]: IMU: Attitude quaternion IMU detected!
[ INFO] [1532619055.848405104]: IMU: High resolution IMU detected!
[ INFO] [1532619056.758370289]: VER: 1.1: Capabilities 0x000000000000e4ef
[ INFO] [1532619056.758512267]: VER: 1.1: Flight software: 010800ff (00000000F3E3ADAE)
[ INFO] [1532619056.758640717]: VER: 1.1: Middleware software: 010800ff (00000000F3E3ADAE)
[ INFO] [1532619056.758772548]: VER: 1.1: OS software: 071600ff (0000000000000000)
[ INFO] [1532619056.758896976]: VER: 1.1: Board hardware: 00000011
[ INFO] [1532619056.759019372]: VER: 1.1: VID/PID: 26ac:0011
[ INFO] [1532619056.759104005]: VER: 1.1: UID: 3036510e36373734
[ WARN] [1532619056.759928950]: CMD: Unexpected command 520, result 0
[ INFO] [1532619065.750967546]: HP: requesting home position
[ INFO] [1532619070.755120888]: WP: mission received
[ INFO] [1532619075.750572389]: HP: requesting home position
[ WARN] [1532619085.713035388]: GP: No GPS fix
[ INFO] [1532619085.750970183]: HP: requesting home position
[ WARN] [1532619092.754518791]: CMD: Unexpected command 183, result 3

header:
seq: 118
stamp:
secs: 1532619200
nsecs: 479749153
frame_id: ‘’
status:

level: 0
name: "mavros: FCU connection"
message: "connected"
hardware_id: "/dev/ttyACM0:921600"
values: 
  - 
    key: "Received packets:"
    value: "49170"
  - 
    key: "Dropped packets:"
    value: "0"
  - 
    key: "Buffer overruns:"
    value: "0"
  - 
    key: "Parse errors:"
    value: "0"
  - 
    key: "Rx sequence number:"
    value: "34"
  - 
    key: "Tx sequence number:"
    value: "134"
  - 
    key: "Rx total bytes:"
    value: "2177802"
  - 
    key: "Tx total bytes:"
    value: "84796"
  - 
    key: "Rx speed:"
    value: "22179.000000"
  - 
    key: "Tx speed:"
    value: "890.000000"

  • level: 2
    name: “mavros: GPS”
    message: “No satellites”
    hardware_id: “/dev/ttyACM0:921600”
    values:

    key: "Satellites visible"
value: "0"
    • key: “Fix type”
      value: “0”
    • key: “EPH (m)”
      value: “99.99”
    • key: “EPV (m)”
      value: “99.99”

  • level: 0
    name: “mavros: Heartbeat”
    message: “Normal”
    hardware_id: “/dev/ttyACM0:921600”
    values:

    key: "Heartbeats since startup"
value: "145"
    • key: “Frequency (Hz)”
      value: “0.959986”
    • key: “Vehicle type”
      value: “Quadrotor”
    • key: “Autopilot type”
      value: “PX4 Autopilot”
    • key: “Mode”
      value: “MANUAL”
    • key: “System status”
      value: “Standby”

  • level: 0
    name: “mavros: System”
    message: “Normal”
    hardware_id: “/dev/ttyACM0:921600”
    values:

    key: "Sensor present"
value: "0x0027002F"
    • key: “Sensor enabled”
      value: “0x0021000F”
    • key: “Sensor helth”
      value: “0x0027002F”
    • key: “3D gyro”
      value: “Ok”
    • key: “3D accelerometer”
      value: “Ok”
    • key: “3D magnetometer”
      value: “Ok”
    • key: “absolute pressure”
      value: “Ok”
    • key: “rc receiver”
      value: “Ok”
    • key: “AHRS subsystem health”
      value: “Ok”
    • key: “CPU Load (%)”
      value: “61.1”
    • key: “Drop rate (%)”
      value: “0.0”
    • key: “Errors comm”
      value: “0”
    • key: “Errors count #1”
      value: “0”
    • key: “Errors count #2”
      value: “0”
    • key: “Errors count #3”
      value: “0”
    • key: “Errors count #4”
      value: “0”

  • level: 0
    name: “mavros: Battery”
    message: “Normal”
    hardware_id: “/dev/ttyACM0:921600”
    values:

    key: "Voltage"
value: "22.58"
    • key: “Current”
      value: “0.0”
    • key: “Remaining”
      value: “49.0”

  • level: 0
    name: “mavros: Time Sync”
    message: “Normal”
    hardware_id: “/dev/ttyACM0:921600”
    values:

    key: "Timesyncs since startup"
value: "1449"
    • key: “Frequency (Hz)”
      value: “9.999868”
    • key: “Last dt (ms)”
      value: “0.492667”
    • key: “Mean dt (ms)”
      value: “0.040468”
    • key: “Last system time (s)”
      value: “24659.926831000”
    • key: “Time offset (s)”
      value: “1532594540.519011736”

header: