Wiki / Devices
Power Functions (IR)
LEGO Power Functions (2007–2018) is the motor and battery system that followed the RCX era. The IR RC Receiver (8884) takes commands from the IR Speed Remote (8879) or IR Remote (8885) over infrared and switches up to 2 motor outputs, making the receiver a true optical control target.
Optical input — fully controllable
Unlike NXT, EV3, and WeDo, where the optics is only a sensor, the PF receiver is a true optical control target: any IR emitter sending the documented PF RC protocol can drive its motors. The principle is the same as VLL but with a 38 kHz carrier instead of baseband.
How to control it today
- Original PF remotes, or
- Arduino/ESP32 + IR LED sending the PF protocol (mature libraries exist; e.g.
LEGOPowerFunctions, and Arduino receiver demos). See Arduino · ESP32 + LED and Power Functions RC (IR). - 4 channels → 4 models at once; PWM 7 steps fwd/rev + brake/float.
The carrier is 38 kHz, so it requires an IR LED modulated at 38 kHz (a standard IR-remote emitter), not the bare on/off LED used for baseband VLL.
Links
- Receiver 8884 (Rebrickable · доп: LEGO.com) · remotes 8879 (Speed) / 8885 (Rebrickable · доп: LEGO.com). See Sets & bricks index.
- Spec PDF: Power Functions RC (IR) → philohome.com/pf.
- Code: Arduino-PowerFunctions (send) · ArduinoLegoIrReceiver (decode) · pf-recorder.