Speed actuators
A Speed actuator drives a bidirectional DC motor through an H-bridge. You command a signed percentage from −100% to +100%: the sign sets direction and the magnitude sets speed. 0% brakes/coasts to a stop.
Catalog types that use this control kind:
| Type | Typical use |
|---|---|
| DC Motor (H-bridge) | Bidirectional DC motor speed |
| Conveyor / Belt | Bidirectional conveyor or belt drive |
Both wire up as an H-bridge output (gpio-motor) — e.g. an L298N, TB6612FNG, or DRV8871.
Firmware requirement: H-bridge speed control needs gateway firmware 1.4.0 or newer. Update from Gateways → Update firmware first.
Add one
- Devices → Add device → Actuator, pick a type from the Motion family.
- Choose the gateway and accept the suggested IN1 / IN2 / EN pins.
- Save. The Control panel shows a centered −100…100% slider (left = reverse, right = forward).
Connection fields
| Field | Meaning | Default |
|---|---|---|
in1Pin / in2Pin |
H-bridge direction inputs | from pin recommendation |
enPin |
PWM enable/speed pin | from pin recommendation |
frequencyHz |
PWM frequency on the enable pin | 1000 Hz |
defaultState |
Safe state to fall back to (0 = stopped) | 0 |
Some H-bridge boards combine direction and speed differently (e.g. PWM on IN1/IN2 directly). The Synacl driver uses IN1/IN2 for direction + EN for PWM speed; wire your board to match, or tie EN high and adjust if your board is the two-PWM type.
Control it
- Device page / dashboard — drag the slider either side of center. Positive = forward, negative = reverse, center = stop. It commits on release. On a dashboard, add the Actuator widget.
- The command is
{ op: 'speed', pct: -100..100 }. The gateway maps the sign to direction (sets IN1/IN2) and the magnitude to PWM duty on EN (duty = round(|pct| × 255 / 100)).pct: 0stops the motor.
Automate it
- Rules — when the tank is full, run the conveyor at 60% forward; when empty, stop (set speed 0).
- Macros — speed is direct/rule-driven; there's no dedicated macro step for it (use a rule or the device-command path). For stepwise positioning use a Move actuator instead.
Safety
- On connection loss the gateway drives the motor to
defaultState(stopped). - Reversing at full speed is hard on motors and supplies — ramp through center in your rule/sequence if the load is heavy.
Troubleshooting
- Runs one way only → IN1/IN2 wiring or the board is a two-PWM type; check the wiring note above.
- No speed control, only on/off → EN isn't on a PWM-capable pin, or it's tied high on the board.
- Stalls / resets the board → motor inrush is browning out the supply; power the motor from a separate supply with a common ground.
See also the actuators overview and Move actuators.