Example: Autopilot Server ​
The Autopilot Server example creates two instances of MAVSDK, representing a client (GCS) and a server (Vehicle). The MAVSDK instances communicates with each other via UDP transmitting telemetry, publishing parameters, missions and takeoff commands.
INFO
This example shows how to use MAVSDK Server Plugins! This is a good starting point if you are looking to implement MAVLink services to a non-MAVLink compatible system.
Running the Example ​
The example is built and run in the normal way (as described here).
The example terminal output should be similar to that shown below:
INFO
This is from a debug build of the SDK. A release build will omit the "Debug" messages.
$ ./autopilot_server[04:44:24|Info ] MAVSDK version: v0.44.0 (mavsdk_impl.cpp:29)
[04:44:24|Info ] MAVSDK version: v0.44.0 (mavsdk_impl.cpp:29)
Connected!
[04:44:24|Error] Sending message failed (mavsdk_impl.cpp:278)
[04:44:24|Debug] Initializing connection to remote system... (mavsdk_impl.cpp:473)
Connected autopilot server side!
Sleeping thread
[04:44:24|Info ] New system on: 127.0.0.1:40799 (with sysid: 1) (udp_connection.cpp:194)
[04:44:24|Debug] New: System ID: 1 Comp ID: 1 (mavsdk_impl.cpp:475)
[04:44:24|Debug] Component Autopilot (1) added. (system_impl.cpp:372)
[04:44:24|Debug] New: System ID: 245 Comp ID: 190 (mavsdk_impl.cpp:222)
[04:44:24|Debug] Component Unsupported component (190) added. (system_impl.cpp:372)
[04:44:25|Debug] Discovered 1 component(s) (system_impl.cpp:520)
Discovered Autopilot from Client
[04:44:25|Debug] Autopilot Capabilities Request (system_impl.cpp:297)
Setting System
MissionRawServer created
[04:44:35|Debug] Setting interval for msg id: 245 interval_ms:1000 (telemetry_server_impl.cpp:38)
[04:44:35|Debug] Request Param CAL_GYRO0_ID (mavlink_parameters.cpp:756)
[04:44:35|Debug] Request Param CAL_ACC0_ID (mavlink_parameters.cpp:756)
[04:44:35|Debug] Request Param CAL_MAG0_ID (mavlink_parameters.cpp:756)
[04:44:35|Debug] Request Param SYS_HITL (mavlink_parameters.cpp:756)
[04:44:40|Warn ] command unsupported (512). (mavlink_commands.cpp:205)
[04:44:41|Debug] Falling back to gimbal protocol v1 (mission_impl.cpp:131)
[04:44:45|Debug] Request Param my_param (mavlink_parameters.cpp:756)
Found Param my_param: 1
Creating Mission
Uploading mission...
SystemID1
[04:44:45|Debug] Receive Mission Count in Server (mission_raw_server_impl.cpp:150)
Received Uploaded Mission!
mission_plan:
{
mission_items: [mission_item:
{
seq: 0
frame: 6
command: 16
current: 1
autocontinue: 1
param1: 0.5
param2: 1
param3: 0
param4: nan
Mission uploaded. x:
473981703
y: 85456490
z: 10
mission_type: 0
}, mission_item:
{
seq: 1
frame: 2
command: 178
current: 0
autocontinue: 1
param1: 1
param2: 5
param3: -1
param4: 0
x: 0
y: 0
z: nan
mission_type: 0
}, mission_item:
{
seq: 2
frame: 2
command: 204
current: 0
autocontinue: 1
param1: 2
param2: 0
param3: 0
param4: 1
x: 0
y: 0
z: 2
mission_type: 0
}, mission_item:
{
seq: 3
frame: 2
command: 205
current: 0
autocontinue: 1
param1: 20
param2: 0
param3: 60
param4: nan
x: 0
y: 0
z: 2
mission_type: 0
}]
}
Current Item Changed!
Current Item: mission_item:
{
seq: 0
frame: 6
command: 16
current: 1
autocontinue: 1
param1: 0.5
param2: 1
param3: 0
param4: nan
x: 473981703
y: [8545649004:44:45|Debug]
z: 10
mission_type: 0
}
current: 0, total: 1Current Item Changed! (
Current Item: mission_item:
{
mission_impl.cpp seq: 1
frame: 2
command: 178
current: 0
autocontinue: 1
param1: :1839)
Current: 0
Total: 1
param2: 5
param3: -1
param4: 0
x: 0
y: 0
z: nan
mission_type: 0
}
[Current Item Changed!
Current Item: mission_item:
{
seq: 2
frame: 2
command: 204
current: 0
autocontinue: 1
param1: 2
param2: 0
param3: 0
param4: 1
x: 0
y: 0
z: 2
mission_type: 0
}
Current Item Changed!
Current Item: mission_item:
{
seq: 3
frame: 2
command: 205
current: 0
autocontinue: 1
param1: 20
param2: 0
param3: 60
param4: nan
x: 0
y: 0
z: 2
mission_type: 0
}
Current Item Changed!
Current Item: mission_item:
{
seq: 0
frame: 6
command: 16
current: 1
autocontinue: 1
param1: 0.5
param2: 1
param3: 0
param4: nan
x: 473981703
y: 85456490
z: 10
mission_type: 0
}
04:44:45|Debug] current: 1, total: 1 (mission_impl.cpp:839)
Current: 1
Total: 1
Clear All Mission!
Clear Mission Request
[04:45:05|Debug] Setting interval for msg id: 33 interval_ms:1000 (telemetry_server_impl.cpp:38)
Arming...
Altitude: 0 m
[04:45:05|Debug] Set Param Request: MIS_TAKEOFF_ALT (mavlink_parameters.cpp:724)
Taking off...
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
Altitude: 10 m
...How it works ​
By creating two MAVSDK instances on separate threads, configuring them and then using different plugins on each, we are able to create a full MAVLink system (GCS <-> Vehicle) in one program.
Each plugin (and it's respective server plugin) implements a particular MAVLink service. By utilising the server plugins and client plugins we are able to create a full MAVLink system, without the need for a separate external autopilot.