Peter BarkerandClaude Opus 4.8
5810830961
The rangefinder_quality_test.lua example (driving the Sub RngfndQuality autotest) pushes a distance/quality/status through the scripting range finder driver interface, waits UPDATE_PERIOD_MS, then reads it back through the client interface and checks it matches. The value is copied from the driver state to the client-facing state by a periodic task on the main loop, which is a different thread to the scripting VM. Under host load (e.g. parallel autotest) or high SIM_SPEEDUP that copy can land after the read, so the client still reports the previous test's value and the script emits a spurious failure -- reproduced at --speedup=40, where the 28m test read back 27m and reported "#complete#: !!failure!!". Retry the read up to MAX_EVAL_RETRIES times (UPDATE_PERIOD_MS apart) before declaring a mismatch, so a slow cross-thread copy is waited out while a genuine mismatch still fails once the retries are exhausted. With this RngfndQuality passes 20/20 at --speedup=40 and 100 (was ~1 in 6 failing). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
AP_Scripting
Enabling Scripting Support in Builds
Scripting is automatically enabled on all boards with more than 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.
Lua Source Code
The Lua 5.3.6 source code is vendored in lua/. This is a customized
version of the official
distribution. Where possible,
differences have been marked of the code.
Lua (not including modifications) is distributed under the terms of the MIT license.