PicoFFB

Force feedback controller firmware for the RP2040 (Raspberry Pi Pico) targeting brushed DC motors with quadrature encoders.

USB VID/PID: 1209:0FFC — composite CDC serial + HID FFB wheel. v0.3.0

Pinout

GPIO	Signal
0	Motor L forward PWM
1	Motor L reverse PWM
2	Motor R forward PWM
3	Motor R reverse PWM
4	Motor enable (active high)
5	Fan PWM (SSR)
9	Encoder A
10	Encoder B
16	WS2812 status LED
26	Throttle ADC (pedal 0)
27	Brake ADC (pedal 1)
28	Clutch ADC (pedal 2)
29	Temp sensor ADC (thermocouple/NTC)
BOOTSEL	Press to recenter wheel

Features

• USB HID Force Feedback — 11 effect types, 40 simultaneous effects, full PID descriptor
• FFB Engine — spring, damper, friction, inertia, constant, ramp, periodic (sine/square/triangle/saw), envelope
• Dual Motor PWM — H-bridge control, per-motor gain, power curve, ~30kHz silent PWM
• PIO Quadrature Encoder — hardware-level decoding via RP2040 PIO+DMA
• Endstops — soft limits at maxdeg/2, configurable strength
• 3× ADC Pedals — throttle/brake/clutch with calibration
• Thermal Protection — software estimate or real sensor (thermocouple/NTC), fan curve, auto power limiting
• Flash Config — dual-block CRC storage, all settings persist across reboot
• WS2812 LED — temperature-based color (green/orange/red)
• Serial Protocol — OK/ERR/JSON commands, 100ms telemetry stream
• Companion App — native GUI for tuning, profiles, live telemetry

Build

$env:PICO_SDK_PATH = "$env:USERPROFILE\.pico-sdk\sdk\2.3.0"
cmake -G "Ninja" -B build -S .
cmake --build build

Flash build/PicoFFB.uf2 via bootloader (hold BOOTSEL, plug USB).

Quick Start

1. Flash firmware
2. Open serial terminal at 115200 baud
3. Type center to calibrate wheel center
4. Type save to persist

For full configuration, use the companion app:

pip install customtkinter pyserial
python companion/companion_app.py

Shell Commands

FFB & Motor

ffb on/off | motor <v> | center | max <v> | curve <v> | gainl/r <v>

Encoder & Endstops

ppr <v> | maxdeg <v> | estopstr <v>

Effect Scalers

sspring/sdamper/sfriction/sinertia <v>

Pedals

calmin <0-2> | calmax <0-2> | calib <0-2> | pedal_enabled <0/1>

Thermal

thermalsrc <0-2> | tc_type <0-2> | tc_slope/tc_offset <v> ntc_r25/ntc_beta/ntc_rfixed <v> | ntc_invert <0/1> fanmin/fanstart/fanmax <v> | thstart/thramp <v> | temp

System

motor_enabled <0/1> | save | debug on/off | tel on/off | status | ver | dump

Serial Protocol

See ./PROTOCOL.md for full protocol documentation. Telemetry streams at 100ms via tel on. All command responses prefixed OK/ERR.

Reference

• FFBHub/ — prior RP2040 FFB firmware (descriptor donor)
• OpenFFBoard/ — upstream STM32 firmware (effect math reference)