sitl-ops

name	sitl-ops
description	Operate ArduPilot SITL via MAVLink (start/stop/status, arm, takeoff, mode, param get/set) and report concise state for Discord or chat. Use when user asks to control SITL vehicle or query live vehicle telemetry/state.

SITL Ops (ArduPilot MAVLink)

Use this skill for SITL only operations.

Safety Defaults

• Target endpoint is local by default: udp:127.0.0.1:14550
• Do not send control commands unless user explicitly asks.
• For potentially risky commands (arm/takeoff/mode/param set), confirm intent if ambiguous.

Setup (one-time)

bash skills/sitl-ops/scripts/setup_venv.sh

Commands (via bundled script)

Use:

python3 skills/sitl-ops/scripts/sitl_mav.py --help

For Discord/chat command-style input, use dispatcher:

bash skills/sitl-ops/scripts/sitl_dispatch.sh "!sitl status"

State query

python3 skills/sitl-ops/scripts/sitl_mav.py status

Returns: mode, armed, battery, lat/lon/alt, roll/pitch/yaw, map_url (Google Maps pin).

Arm

python3 skills/sitl-ops/scripts/sitl_mav.py arm

Takeoff (meters)

python3 skills/sitl-ops/scripts/sitl_mav.py takeoff --alt 10

Important:

• Use MAV_CMD_NAV_TAKEOFF flow (sitl_mav.py takeoff) for liftoff from ground.
• Do not use only position-target commands for initial liftoff from disarmed/just-armed state (can trigger auto-disarm race and no climb).
• After takeoff command, wait 3–5s then run status to verify climb.

Mode change

python3 skills/sitl-ops/scripts/sitl_mav.py mode --name GUIDED

Parameter get/set

python3 skills/sitl-ops/scripts/sitl_mav.py param-get --name ARMING_CHECK
python3 skills/sitl-ops/scripts/sitl_mav.py param-set --name ARMING_CHECK --value 1

Discord handling style

When request comes from Discord, keep responses short:

• Action result (OK/NG)
• Key state line (mode/armed/battery/position)
• Error reason (if any)

Recommended Discord command mapping:

• !sitl start
• !sitl stop
• !sitl status
• !sitl arm
• !sitl takeoff 10
• !sitl mode GUIDED
• !sitl param get ARMING_CHECK
• !sitl param set ARMING_CHECK 1

Execution pattern:

1. Parse user message (if starts with !sitl)
2. Run bash skills/sitl-ops/scripts/sitl_dispatch.sh "<user_message>"
3. Return concise result + one-line state summary

Build/Dependency Recovery Playbook (mandatory when build fails)

When SITL build/start fails due missing Python package(s), attempt auto-recovery before reporting failure.

1. Capture last error log:

tail -n 120 /tmp/sitl_copter.log

2. If error contains you need to install empy, ModuleNotFoundError, or No such file or directory: 'mavproxy.py':

bash skills/sitl-ops/scripts/setup_venv.sh

3. If system python still complains (PEP668 / externally-managed env), run fallback install command:

python3 -m pip install --user --break-system-packages empy==3.3.4 pymavlink MAVProxy

4. Never delete build/ or run waf clean during routine recovery. Preserve incremental build cache.
5. Preflight-check mavproxy.py before sim_vehicle.py launch:

cd /home/hfuji/.openclaw/workspace/GitHub/ardupilot
./.venv/bin/mavproxy.py --help >/dev/null

If this fails, run:

./.venv/bin/python -m pip install MAVProxy

6. Ensure .venv/bin is on PATH when launching sim_vehicle (so mavproxy.py is found).
7. For restart-only cases (no source/config change), start with -N to skip rebuild:

cd /home/hfuji/.openclaw/workspace/GitHub/ardupilot
nohup env PATH="/home/hfuji/.openclaw/workspace/GitHub/ardupilot/.venv/bin:$PATH" ./Tools/autotest/sim_vehicle.py -N -v Copter -L Kawachi --out=100.76.194.34:14550 > /tmp/sitl_copter.log 2>&1 &

8. Only if binary missing or build actually required, run normal start (rebuild allowed):

cd /home/hfuji/.openclaw/workspace/GitHub/ardupilot
nohup env PATH="/home/hfuji/.openclaw/workspace/GitHub/ardupilot/.venv/bin:$PATH" ./Tools/autotest/sim_vehicle.py -v Copter -L Kawachi --out=100.76.194.34:14550 > /tmp/sitl_copter.log 2>&1 &

9. Re-check heartbeat and report result.

Notes

• Requires pymavlink in runtime (pip install pymavlink).
• setup_venv.sh installs pymavlink, empy==3.3.4, and MAVProxy.
• Dispatcher prefers ~/.openclaw/workspace/.venv/bin/python when present.
• Override Python with SITL_VENV_PYTHON=/path/to/python.
• !sitl start/stop uses sim_vehicle.py and supports:
  • SITL_AP_ROOT (default: /home/hfuji/.openclaw/workspace/GitHub/ardupilot)
  • SITL_AP_VENV_ACTIVATE (default: /home/hfuji/venv-ardupilot/bin/activate)
  • SITL_START_ARGS (default: -v Copter -L Kawachi --no-mavproxy)
  • SITL_LOG (default: /tmp/sitl_copter.log)
• Command endpoint auto-resolution (when SITL_MASTER unset):
  • if mavproxy.py is running: udp:127.0.0.1:14550
  • else if SITL TCP is listening: tcp:127.0.0.1:5760
• Override endpoint with SITL_MASTER=udp:127.0.0.1:14551 (or tcp).