Orion — motorized winch

Orion is a DMX-controlled kinetic fixture: a TMC2209-driven winch (LED Lifter v5 board) with sensorless homing, an adaptive stall-detection calibration wizard, and optional LED outputs rendered alongside the motor. Status: alpha.

Safety first. Orion moves loads overhead. RavLight provides stall detection, soft limits and watchdogs, but rigging, load ratings and safeties are the operator's responsibility. Never stand under a moving load, and always use secondary suspension where people are below.

Motor stack

A TMC2209 driver, configured over single-wire UART, with step generation by FastAccelStepper. Homing is sensorless: StallGuard4 reads the motor's back-EMF load signal, so the winch finds its home position by gently driving into the mechanical stop — no endstop switch required. Mechanical calibration (drum diameter, steps per revolution, gear ratio) converts steps to real distance, with a cm/inch selector in the UI.

Setup wizard

A guided 7-step wizard in the fixture section walks a new rig from zero to calibrated:

Mechanical — drum diameter, steps/rev, gear ratio.
Motor electrical — run/hold currents and speed/acceleration limits.
Homing direction — which way is "toward home" for your rig.
Home position — manual-first: jog to the reference point and set it, before trusting sensorless homing.
Travel limits — soft limits the motor will never cross.
Profile sweep — automatic StallGuard characterization (below).
Safety — watchdog and recovery behavior.

StallGuard profile sweep

StallGuard readings vary with speed and direction, so a fixed threshold either misses real stalls or trips on phantom ones. The sweep runs the motor through 8 speed bins × 2 directions, records the load signal profile, and auto-derives an operational stall threshold. A confidence selector sets how many standard deviations of margin you want — from Aggressive (2σ) for fast stall response to Very tolerant (5σ) for mechanically noisy rigs that would otherwise false-trigger.

Operating options

Manual mode — bypasses all stall safety, for rigs whose load profile can't be measured reliably. Use with care.
Auto-home at boot — for direct-drive rigs where the load drops when power is removed; the fixture re-homes itself before accepting positions.
Keep home after stall — for worm-gear rigs that physically cannot lose position; skips re-homing after an operational stall.
Stall recovery — auto-rehome (re-run homing in place, max 3 retries) or drop & rehome, chosen per rig.

DMX control

Personalities of 4–6 channels: position in 8-bit or 16-bit (coarse + fine) flavors, plus speed, acceleration and a function channel (home, e-stop, clear fault and similar commands triggered from the console). Position maps between the calibrated travel limits.

DMX-loss watchdog

If the DMX source disappears (per-universe detection), Orion executes a configured action: e-stop, return home, or do nothing (hold position). Pick per installation — a hanging prop over a stage wants different behavior than a warehouse test bench.

Optional LED outputs

The LED Lifter v5 board exposes 4 optional pixel outputs (GPIO 4, 5, 15, 16) rendered Elyon-style alongside the motor — a lit element on the moving load, driven from the same universe pool. Board details on the boards page.