petrosilius
1d810bfa6f
This script uses the scaled output from the antennatracker servos and map them to corresponding Pelco-D messages to be sent via a RS-485 interface to a motorized base (can be anything from motorized tracker to a PTZ camera). If your FCU doesnt offer a RS-485 interface by default, you can use or TTL-RS485- or USB-RS485-adapters. Pelco-D allows to control using either speed-/differential- or absolute-control control of the pan-/tilt-axis. Currently the script uses speed based control using by mapping the "ContinuousRotation" type servos outputs to the corresponding Pelco-D messages. The absolute control messages are implemented nevertheless for future use. The script assumes therefor at least the following parameters to be set: SCR_ENABLE = 1 SERVO_PITCH_TYPE = 2 # ContinuousRotation type servo SERVO_YAW_TYPE = 2 # ContinuousRotation type servo SERIALx_PROTOCOL = 28 # serial port used by luascript Additionally the PITCH2SRV and YAW2SRV tuning needs to be done as described by the antennatracker description. Also keep attention to the PITCH_MIN, PITCH_MAX and YAW_RANGE parameters to fit your Pelco-D hardware!
AP_Scripting
Enabling Scripting Support in Builds
Scripting is automatically enabled on all boards with at least 1MB of flash space. The following example enables scripting, builds the ArduPlane firmware for the Cube, and uploads it.
$ waf configure --board=CubeBlack
$ waf plane
$ waf plane --upload
To run SITL you can simply use the sim_vehicle.py script which will wrap the configuration, compilation,
and launching of the simulation into one command for you.
$ Tools/autotest/sim_vehicle.py -v ArduPlane
Once you have a vehicle flashed with scripting you need to set the SCR_ENABLE parameter to 1 to enable scripting and reboot.
Adding Scripts
The vehicle will automatically look for and launch any scripts that are contained in the scripts folder when it starts.
On real hardware this should be inside of the APM folder of the SD card. In SITL this should be in the working directory (typically the main ardupilot directory).
An example script is given below:
function update () -- periodic function that will be called
local current_pos = ahrs:get_location() -- fetch the current position of the vehicle
local home = ahrs:get_home() -- fetch the home position of the vehicle
if current_pos and home then -- check that both a vehicle location, and home location are available
local distance = current_pos:get_distance(home) -- calculate the distance from home in meters
if distance > 1000 then -- if more then 1000 meters away
distance = 1000; -- clamp the distance to 1000 meters
end
SRV_Channels:set_output_pwm(96, 1000 + distance) -- set the servo assigned function 96 (scripting3) to a proportional value
end
return update, 1000 -- request "update" to be rerun again 1000 milliseconds (1 second) from now
end
return update, 1000 -- request "update" to be the first time 1000 milliseconds (1 second) after script is loaded
Examples
See the code examples folder
Working with bindings
Edit bindings.desc and rebuild. The waf build will automatically re-run the code generator.