Hi I am building an AUV for my final year project. I have connected the pixhawk to the qgroundcontrol and I have also setup and calibrated my controller with it.
The first issue is that when I go to check the MAVLink Inspector, I do not see any Manual Control message topic. The RC_Channel values are also not changing an d neither are the Servo_Output_Raw values changing. I have already armed the vehicle before checking this. I also tried using a multimeter to check my actual pixhawk pins but the values remain constant and are not changing.
Secondly, I wrote a script that publishes my joy node inputs into cmd_vel topic after converting it on ros. I then had another script to convert these to RC override signals and publish it to the /mavros/rc/override topic. While this topic is able to echo my inputs from the joystick, the issue is that the actual pixhawk pins do not output other values and they just remain constant.
What could be the issue and what could I be doing wrong?
I have also attached a sample of the code that converts my cmd_vel values to mavros/rc/override values below and I am running this with the mavros px4.launch file
#!/usr/bin/env python3
import rospy
from geometry_msgs.msg import Twist
from mavros_msgs.msg import OverrideRCIn
class PX4Interface:
def __init__(self):
rospy.init_node('px4_interface')
self.rc_pub = rospy.Publisher('/mavros/rc/override', OverrideRCIn, queue_size=10)
rospy.Subscriber('/cmd_vel', Twist, self.cmd_vel_callback)
self.roll_channel = 0
self.pitch_channel = 1
self.throttle_channel = 2
self.yaw_channel = 3
self.mode_channel = 4
self.aux1_channel = 5
self.rc_min = 800 #1100
self.rc_mid = 900 #1500
self.rc_max = 1300 #1900
self.last_twist = Twist()
self.timer = rospy.Timer(rospy.Duration(0.1), self.timer_callback) # 10 Hz
def cmd_vel_callback(self, twist_msg):
self.last_twist = twist_msg
def scale_to_rc(self, value):
return int(self.rc_mid + (value * (self.rc_max - self.rc_min))) #/2
def timer_callback(self, event):
self.process_and_publish_rc(self.last_twist)
def process_and_publish_rc(self, twist_msg):
rc_msg = OverrideRCIn()
rc_msg.channels = [65535] * 18 # No override for all channels by default
# Convert `cmd_vel` to RC PWM values
roll = self.scale_to_rc(twist_msg.linear.y) # Assuming y is roll
pitch = self.scale_to_rc(twist_msg.linear.x) # Assuming x is pitch
throttle = self.scale_to_rc(twist_msg.linear.z)
yaw = self.scale_to_rc(twist_msg.angular.z)
# Ensure RC values are within bounds
rc_msg.channels[self.roll_channel] = max(self.rc_min, min(self.rc_max, roll))
rc_msg.channels[self.pitch_channel] = max(self.rc_min, min(self.rc_max, pitch))
rc_msg.channels[self.throttle_channel] = max(self.rc_min, min(self.rc_max, throttle))
rc_msg.channels[self.yaw_channel] = max(self.rc_min, min(self.rc_max, yaw))
# Publish to Pixhawk
self.rc_pub.publish(rc_msg)
def run(self):
rospy.spin()
if __name__ == '__main__':
node = PX4Interface()
node.run()