AutoDrive example

The driving loop machbus drive keyboard runs, with the terminal taken out so it is readable and runnable offline.

cargo run --example autodrive_keyboard

Look for:

• examples/autodrive_keyboard.rs

Expected output shape

=== AutoDrive: steering + speed behind one lifecycle ===

[refused] arm before any ECU answered: link_down
[engaged] status = ActiveNotLimited
[heartbeat] 5 guidance commands in 500 ms of driving
[released] status = Fault   stop = Some("operator_override")
[refused] engage while latched: stop_latched
[cleared] latch released; re-engage is allowed again

Each line is one of the four things that are easy to get wrong:

1. link_down — arming before any steering ECU answers is refused, and the refusal names the precondition. AutoDrive returns refusals rather than silently ignoring, because a client that asks to steer and is ignored cannot tell “commanded” from “declined”.
2. 5 commands in 500 ms — the 100 ms cadence (MIN_TX_INTERVAL_MS, the ISO 11783-7 §5.2.7.2 minimum). The command is the heartbeat the steering ECU times out on, so it goes out even when the setpoint has not changed.
3. Fault + operator_override — releasing the dead-man disengages and falls back to DriveCommand::halt(). Losing the dead-man must land in the same place; see the drive tool safety model.
4. stop_latched then cleared — the stop latches, so re-engaging is refused until an explicit, separate clear_stop(). Clearing a fault is not by itself consent to move.

The example feeds itself Agricultural Guidance Machine Info (PGN 0xAC00), because AutoDrive will not engage without a steering ECU answering — that refusal is the first line of output.

What this proves

• AutoDrive gates arm/engage on preconditions and reports which one failed.
• The command cadence is a heartbeat at the conformance minimum.
• A safe stop latches and needs a deliberate clear.

What this does not prove

Anything about closed-loop steering or speed control, path planning, operator supervision, actuator safety, real-machine timing, interoperability with a specific tractor, or whether a given tractor acts on an unauthenticated speed command at all — see AutoDrive → Do I need TIM?. machbus is not a safety system and is not certified.

See also

• AutoDrive (steering + speed) — the plugin.
• machbus drive safety model — the operator-input layer around it: dead-man, arm latch, and losing the controller.