I am using 3dr telemetry, I was able to send and receive the data from it using MP, but what if I have my own mission planner, and I want to send and receive data? How can I do that ?
I am creating a python code, which will receive data from the copter through telemetry and also send the data. I know the messages will be in the format of MAVLINK. Is there any specific API for that ?
Did you have a look at GitHub - ArduPilot/pymavlink: python MAVLink interface and utilities
1 Like
Can I use ROS for that as I didnt find any topic.
Moreover, I was trying to implement pymavlink
import time
from pymavlink import mavutil
class Commns:
def __init__(self, device, baud):
self.device = device
self.baud = baud
self.connection = None
def connect(self):
try:
self.connection = mavutil.mavlink_connection(self.device, baud=self.baud)
self.connection.wait_heartbeat()
print("Heartbeat from system (system %u component %u)" % (
self.connection.target_system, self.connection.target_component))
except Exception as e:
print("Error connecting to Pixhawk:", str(e))
def close(self):
if self.connection:
self.connection.close()
print("Connection closed.")
if __name__ == "__main__":
device = '/dev/ttyUSB0' # Adjust this to the appropriate device name
baud = 115200 # Typical baud rate for telemetry radios
# Create an instance of PixhawkConnector
connector = Commns(device, baud)
# Connect to Pixhawk
connector.connect()
# Do other tasks here...
# Close the connection when done
connector.close()
If I want to check my code on SITL what baud rate and device/port should be use ?
change device to ‘tcp:localhost:5762’ and you should be good. Port 5760 is normally SERIAL0 which Mission Planner will connect to when you start SITL, port 5762 is SERIAL1
You can use MAVROS if you’re using ROS
import time
from pymavlink import mavutil
class Connection:
# The connection class is used to connect the vehicle,
# further, more the class can also connect wit sitl for simulation and debug purposes.
def __init__(self):
self.connection = None
self.device = None
self.baud = None
self.connection_string = None
def init(self, device, baud):
# To connect with telemetry/devices
self.device = device
self.baud = baud
def init_sitl(self, connection_string):
# to connect with software in the loop
self.connection_string = connection_string
def connect(self):
try:
self.connection = mavutil.mavlink_connection(self.device, baud=self.baud)
self.connection.wait_heartbeat()
print("Heartbeat from system (system %u component %u)" % (
self.connection.target_system, self.connection.target_component))
except Exception as e:
print("Error connecting to Flight Controller:", str(e))
def connect_sitl(self):
try:
self.connection = mavutil.mavlink_connection(self.connection_string)
self.connection.wait_heartbeat()
print("Heartbeat from system (system %u component %u)" % (
self.connection.target_system, self.connection.target_component))
except Exception as e:
print("Error connecting to Flight Controller:", str(e))
def get_instance(self):
return self.connection
def close(self):
if self.connection:
self.connection.close()
print("Connection closed.")
class FlightController:
# Following class is used to perform the basic functions of vehicle
def __init__(self, vehicle):
self.vehicle = vehicle
def turn_on_motor(self):
# arm the motors
self.vehicle.arducopter_arm()
self.vehicle.motors_armed_wait()
print("Turning on Motors")
def turn_off_motor(self):
# disarm the motors
self.vehicle.arducopter_disarm()
self.vehicle.motors_disarmed_wait()
print("Turning off Motors")
def set_mode(self, mode):
# function to set the vehicle mode (i-e guided auto rtl etc)
mode_id = self.vehicle.mode_mapping()[mode]
self.vehicle.set_mode_apm(mode_id)
while True:
ack = self.vehicle.recv_match(type='COMMAND_ACK', blocking=True, timeout=10)
if ack and ack.command == mavutil.mavlink.MAV_CMD_DO_SET_MODE and ack.result == mavutil.mavlink.MAV_RESULT_ACCEPTED:
print("{} mode set successfully...".format(mode))
break
# Function to land the vehicle
def land_vehicle(self):
self.set_mode('LAND')
print("Landing...")
# Function to trigger Return to Launch (RTL)
def rtl_vehicle(self):
self.set_mode('RTL')
print("Returning to Launch...")
# Function to take off
def takeoff(self,altitude=5):
# Command the vehicle to take off
self.vehicle.mav.command_long_send(
self.vehicle.target_system,
self.vehicle.target_component,
mavutil.mavlink.MAV_CMD_NAV_TAKEOFF,
0,
0, 0, 0, 0, 0, 0, altitude
)
if __name__ == "__main__":
try:
device = 'com8' # port
baud = 115200 # baud
connecting_string = 'tcp:127.0.0.1:5762' # sitl connecting sting
connector = Connection()
connector.init_sitl(connecting_string)
connector.connect_sitl()
flight_controller = FlightController(connector.get_instance())
flight_controller.turn_on_motor()
flight_controller.set_mode('GUIDED')
flight_controller.takeoff()
except Exception as e:
print("Exception", e)
I am unable to takeoff in sitll ?
COMMAND_ACK {command : 22, result : 4, progress : 0, result_param2 : 0, target_system : 255, target_component : 0}
when I execute
ack = self.vehicle.recv_match(type='COMMAND_ACK', blocking=True, timeout=10)
I tried your code but just swapped the order in which you send the commands and it works:
flight_controller = FlightController(connector.get_instance()) flight_controller.set_mode('GUIDED') flight_controller.turn_on_motor() flight_controller.takeoff()
So first setting the mode and then arming the motors
Thanks it works. There is one more thing which is confusing me a little.
I want to make a waypoint mission, I know I have to use MAV_CMD_NAV_WAYPOINT, a list of waypoints will be created with this, and auto mode will be use to start waypoint mission.
What I don’t know is that how to upload the data in the flight controller, is there sample template you can tell me or guided?
I haven’t done waypoint uploads with Python before, but there are a sequence of steps to follow which is described here: Mission Protocol · MAVLink Developer Guide
I have written the code, for waypoint mission using pymavlink, which is working.
class Waypoint:
def __init__(self, vehicle):
self.vehicle = vehicle
self.target_locations = None
def init_target_locations(self, target_locations):
self.target_locations = target_locations
msg = dialect.MAVLink_mission_count_message(target_system=self.vehicle.target_system,
target_component=self.vehicle.target_component,
count=len(target_locations) + 2,
mission_type=dialect.MAV_MISSION_TYPE_MISSION)
self.vehicle.mav.send(msg)
# catch a message
message = self.vehicle.recv_match(blocking=True)
# convert this message to dictionary
message = message.to_dict()
# check this message is MISSION_REQUEST
if message["mavpackettype"] == dialect.MAVLink_mission_request_message.msgname:
# check this request is for mission items
if message["mission_type"] == dialect.MAV_MISSION_TYPE_MISSION:
# get the sequence number of requested mission item
seq = message["seq"]
# create mission item int message
if seq == 0:
# create mission item int message that contains the home location (0th mission item)
message = dialect.MAVLink_mission_item_int_message(target_system=self.vehicle.target_system,
target_component=self.vehicle.target_component,
seq=seq,
frame=dialect.MAV_FRAME_GLOBAL,
command=dialect.MAV_CMD_NAV_WAYPOINT,
current=0,
autocontinue=0,
param1=0,
param2=0,
param3=0,
param4=0,
x=0,
y=0,
z=0,
mission_type=dialect.MAV_MISSION_TYPE_MISSION)
# send takeoff mission item
elif seq == 1:
# create mission item int message that contains the takeoff command
message = dialect.MAVLink_mission_item_int_message(target_system=self.vehicle.target_system,
target_component=self.vehicle.target_component,
seq=seq,
frame=dialect.MAV_FRAME_GLOBAL_RELATIVE_ALT,
command=dialect.MAV_CMD_NAV_TAKEOFF,
current=0,
autocontinue=0,
param1=0,
param2=0,
param3=0,
param4=0,
x=0,
y=0,
z=target_locations[0][2],
mission_type=dialect.MAV_MISSION_TYPE_MISSION)
# send target locations to the vehicle
else:
# create mission item int message that contains a target location
message = dialect.MAVLink_mission_item_int_message(target_system=self.vehicle.target_system,
target_component=self.vehicle.target_component,
seq=seq,
frame=dialect.MAV_FRAME_GLOBAL_RELATIVE_ALT,
command=dialect.MAV_CMD_NAV_WAYPOINT,
current=0,
autocontinue=0,
param1=0,
param2=0,
param3=0,
param4=0,
x=int(target_locations[seq - 2][0] * 1e7),
y=int(target_locations[seq - 2][1] * 1e7),
z=target_locations[seq - 2][2],
mission_type=dialect.MAV_MISSION_TYPE_MISSION)
# send the mission item int message to the vehicle
self.vehicle.mav.send(message)
# check this message is MISSION_ACK
elif message["mavpackettype"] == dialect.MAVLink_mission_ack_message.msgname:
# check this acknowledgement is for mission and it is accepted
if message["mission_type"] == dialect.MAV_MISSION_TYPE_MISSION and \
message["type"] == dialect.MAV_MISSION_ACCEPTED:
# break the loop since the upload is successful
print("Mission upload is successful")
if __name__ == "__main__":
try:
connector = Connection()
# device = 'com8' # port
# baud = 115200 # baud
# connector.init(device, baud)
# connector.connect_telemetry()
connecting_string = 'tcp:127.0.0.1:5762' # sitl connecting sting
connector.init_sitl(connecting_string)
connector.connect_sitl()
flight_controller = FlightController(connector.get_instance())
waypoint_mission = Waypoint(connector.get_instance())
flight_controller.get_parameter_value('AUTO_OPTIONS')
flight_controller.set_parameter_value('AUTO_OPTIONS', 3, mavutil.mavlink.MAV_PARAM_TYPE_UINT8)
flight_controller.set_mode('GUIDED')
flight_controller.get_mode()
flight_controller.turn_on_motor()
flight_controller.takeoff()
target_locations = ((-35.361297, 149.161120, 50.0),
(-35.360780, 149.167151, 50.0),
(-35.365115, 149.167647, 50.0),
(-35.364419, 149.161575, 50.0))
waypoint_mission.init_target_locations(target_locations)
flight_controller.set_mode('AUTO')
gps = GPS(connector.get_instance())
gps.gps_3d_location()
# compass = Compass(connector.get_instance())
# compass.get_heading()
except Exception as e:
print("Exception", e)
there is one more guidance I need, how to set a flag for waypoint reach and how can I add actions in it?