Pixhawk PWM AUX Control

[caio-freitas]

I've been trying to control a servo PWM motor with a Pixhawk 2.4.8, on AUX1, running PX4 v1.9.2 and ROS Kinetic, and all I could get was an Error LED from the Pixhawk.
This is the code:
`#include <ros/ros.h>
#include <mavros_msgs/CommandBool.h>
#include <std_msgs/String.h>
#include <mavros_msgs/ActuatorControl.h>
#include <mavros_msgs/CommandLong.h>
#include <mavros_msgs/CommandLongRequest.h>

std_msgs::String message;
mavros_msgs::ActuatorControl servocon;

int main(int argc, char **argv) {
ros::init(argc, argv, "servo_control");
ros::NodeHandle nh;
ros::Rate rate(20.0);
ros::ServiceClient command_client = nh.serviceClient<mavros_msgs::CommandLong>("/mavros/cmd/command");
int index=1;
float value=1900; // thruster value
int pulse_width = (value + 1) * 400 + 1100;
mavros_msgs::CommandLong srv;
srv.request.command = 184; //because it didn't accept mavros_msgs::CommandLong::CMD_DO_SET_SERVO;//
srv.request.param1 = index + 1; // servos are 1-indexed here
srv.request.param2 = pulse_width;
while (ros::ok()) {
bool result = command_client.call(srv);
ros::spinOnce();
rate.sleep();
}
return 0;
}
`

Does anyone know why it doesn't work or how to do it work?

MAVROS version and platform

Mavros: 0.29.2
ROS: Kinetic
Ubuntu: 16.04.5

Autopilot type and version

[ ] ArduPilot
[ X ] PX4

Version: ?3.7.1?

Node logs

It logs nothing

Diagnostics

header:
seq: 59
stamp:
secs: 1567798296
nsecs: 746577989
frame_id: ''
status:

level: 0
name: "mavros: FCU connection"
message: "connected"
hardware_id: "/dev/ttyUSB0:57600"
values: 
  - 
    key: "Received packets:"
    value: "1150"
  - 
    key: "Dropped packets:"
    value: "0"
  - 
    key: "Buffer overruns:"
    value: "0"
  - 
    key: "Parse errors:"
    value: "0"
  - 
    key: "Rx sequence number:"
    value: "121"
  - 
    key: "Tx sequence number:"
    value: "38"
  - 
    key: "Rx total bytes:"
    value: "54243"
  - 
    key: "Tx total bytes:"
    value: "16199"
  - 
    key: "Rx speed:"
    value: "2253.000000"
  - 
    key: "Tx speed:"
    value: "736.000000"

• level: 2
  name: "mavros: GPS"
  message: "No satellites"
  hardware_id: "/dev/ttyUSB0:57600"
  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/ttyUSB0:57600"
  values:

  key: "Heartbeats since startup"
  value: "32"
  

  • key: "Frequency (Hz)"
    value: "0.999983"
  • key: "Vehicle type"
    value: "Hexarotor"
  • key: "Autopilot type"
    value: "PX4 Autopilot"
  • key: "Mode"
    value: "MANUAL"
  • key: "System status"
    value: "Standby"

• level: 2
  name: "mavros: System"
  message: "Sensor helth"
  hardware_id: "/dev/ttyUSB0:57600"
  values:

  key: "Sensor present"
  value: "0x000E002F"
  

  • key: "Sensor enabled"
    value: "0x0021000F"
  • key: "Sensor helth"
    value: "0x000E002F"
  • key: "3D gyro"
    value: "Ok"
  • key: "3D accelerometer"
    value: "Ok"
  • key: "3D magnetometer"
    value: "Ok"
  • key: "absolute pressure"
    value: "Ok"
  • key: "rc receiver"
    value: "Fail"
  • key: "AHRS subsystem health"
    value: "Fail"
  • key: "CPU Load (%)"
    value: "33.1"
  • key: "Drop rate (%)"
    value: "0.0"
  • key: "Errors comm"
    value: "0"
  • key: "Errors count mavconn library. #1"
    value: "0"
  • key: "Errors count Pub/sub for Mavlink.msg #2"
    value: "0"
  • key: "Errors count Plugin loading functionality. #3"
    value: "0"
  • key: "Errors count Diagnostic mesages. #4"
    value: "0"

• level: 0
  name: "mavros: Battery"
  message: "Normal"
  hardware_id: "/dev/ttyUSB0:57600"
  values:

  key: "Voltage"
  value: "65.54"
  

  • key: "Current"
    value: "-0.0"
  • key: "Remaining"
    value: "-1.0"

• level: 2
  name: "mavros: Time Sync"
  message: "No events recorded."
  hardware_id: "/dev/ttyUSB0:57600"
  values:

  key: "Timesyncs since startup"
  value: "0"
  

  • key: "Frequency (Hz)"
    value: "0.000000"

Check ID

OK. I got messages from 1:1.

---

Received 481 messages, from 1 addresses
sys:comp list of messages
1:1 0, 1, 83, 36, 230, 32, 105, 74, 331, 77, 111, 141, 241, 147, 340, 245, 22, 24, 4, 30

[Ken-Thorburn]

Were you able to control an aux port with a mavros command? I just started researching the possibility today.

[dibukk95]

hai
i am also going through the same for last few days.but i am not able to control the aux via mavros.i tried diiferent msgs & various topics but still not able to do.if you figured it please share.

thanks in advance

[purvikpatel]

Hi @dibukk95
Did you find the solution ?

[ntrinite]

Bump for solution?

[tiralonghipol]

@caio-freitas hei, any news on this?