Controllino Posung PWM

PWM speed control for four Posung 24 V DC scroll compressors using a CONTROLLINO MINI.

Why software PWM on all four channels

The Controllino Mini only has three hardware PWM outputs (D1, D2, D5). This firmware drives all four compressor PWM inputs with matched 400 Hz software PWM (compressor 4 on D0) so behaviour is identical across units.

Contents

Path	Purpose
docs/PLAN.md	Implementation plan, pin map, power rules, commissioning
docs/WIRING.md	Signal / STB / level-shift wiring
src/posung_pwm_control.ino	Arduino sketch for CONTROLLINO MINI

Quick start

1. Install Arduino IDE + Controllino board package and the Controllino library.
2. Select board CONTROLLINO MINI.
3. Open src/posung_pwm_control.ino and flash over USB.
4. Wire per docs/WIRING.md (motor power separate; PWM/enable only on the PLC).
5. Serial Monitor at 115200 baud:

help
spd all 40
on 1
status
off all

Defaults (edit after checking your Posung datasheet)

• PWM frequency: 400 Hz
• Capacity 0–100 % → positive duty 20–80 %
• PWM pins: D1, D2, D5, D0
• Enable pins: D3, D4, D6, D7

Hardware notes

• Fuse each compressor on the +24 V power feed. Never route motor current through the Controllino.
• On the Mini, relays share D0–D5 — leave those relay terminals unused while PWM runs.
• If PWM IN is specified as 9–16 V only, use open-collector level shifting (see wiring doc) and set PWM_ACTIVE_HIGH accordingly.