Raspberry Pi Pico USB Joystick Controller for car Simrig

A comprehensive USB HID Joystick implementation for Raspberry Pi Pico with support for buttons, shifters, and analog pedals.

Vibe coded due to not having free time at all / spending such time on said Simrig HW :))

Features

• Direct Mapped Buttons - Physical buttons directly mapped to joystick buttons with debouncing (hazards, DSC, handbrake...)
• Edge-Triggered Buttons - Momentary pulse (300ms) on state change (light switch)
• Combo Button Groups - Two-pin combinations with 200ms detection window (E46 window switches)
• H-Pattern Shifter - Analog stick shifter with reverse gear detection (Logitech or any other)
• Analog Pedals - 16-bit precision pedals via ADS1115 ADC with auto-calibration
• EEPROM Storage - Pedal calibration saved automatically
• Calibration Reset - Hold button to reset pedal calibration

Hardware Requirements

• Raspberry Pi Pico
• ADS1115 16-bit ADC module (for pedals)
• Buttons/switches for input (pull-up mode)
• Shifter with potentiometers (G2x shifter)
• Pedals with potentiometers (G2x pedals)

Required Libraries

Install these libraries via Arduino IDE Library Manager:

1. ezButton - Button debouncing library
2. Joystick (by earlephilhower) - USB HID Joystick for RP2040
3. ADS1115_WE - ADS1115 ADC library (only if using pedals)

Pin Assignments

Default Configuration Example

Component	GPIO Pin	Function
I2C SDA	GP20	ADS1115 Communication
I2C SCL	GP21	ADS1115 Communication
Shifter X	GP26 (ADC0)	Analog X-axis
Shifter Y	GP27 (ADC1)	Analog Y-axis
Reverse	GP22	Digital input (HIGH=Reverse, LOW=6th)

Note: Direct buttons, edge buttons, and combo groups are configured in the code arrays.

Configuration Guide

1. Enable/Disable Features

#define ENABLE_SHIFTER true   // Set to false to disable shifter
#define ENABLE_PEDALS true    // Set to false to disable pedals

2. Direct Buttons

DirectButton directButtons[] = {
  {2, 9},    // Pin GP2 -> Joystick Button 9
  {3, 10},   // Pin GP3 -> Joystick Button 10
  // Add more buttons here
};

3. Edge-Triggered Buttons

EdgeButton edgeButtons[] = {
  {13, 16}   // Pin GP13 -> Button 16 (300ms pulse on state change)
};

4. Combo Button Groups

ComboGroup comboGroups[] = {
  {5, 6, 1, 2, 3, 4},   // Pins GP5, GP6 -> Buttons 1-4
  // pin1, pin2, btn_p1_only, btn_combo_12, btn_p2_only, btn_combo_21
};

Combo Logic:

• Press Pin1 alone for 200ms → Button 1
• Press Pin1, then Pin2 within 200ms → Button 2
• Press Pin2 alone for 200ms → Button 3
• Press Pin2, then Pin1 within 200ms → Button 4

5. Shifter Configuration

ShifterConfig shifter = {
  26,    // X_AXIS_PIN (GP26/ADC0)
  27,    // Y_AXIS_PIN (GP27/ADC1)
  22,    // REVERSE_PIN (GP22)
  320,   // X_LEFT_THRESHOLD
  600,   // X_RIGHT_THRESHOLD
  650,   // Y_TOP_THRESHOLD
  250,   // Y_BOTTOM_THRESHOLD
  {17, 18, 19, 20, 21, 22, 23, 24}  // Joystick buttons for gears 0-7
};

Gear Mapping:

     1   3   5
     |   |   |
     2   4   6/R

Gear 0 = Neutral (no button pressed)
Gear 7 = Reverse (bottom-right + HIGH on reverse pin)

6. Pedal Configuration

PedalConfig pedals[NUM_PEDALS] = {
  {0, 3, 5},  // ADS1115 A0 -> Rx axis, 5% deadzone
  {2, 5, 3},  // ADS1115 A2 -> Rz axis, 3% deadzone
  {1, 4, 3}   // ADS1115 A1 -> Ry axis, 3% deadzone
  // channel, joystick_axis, deadzone_percent
};

Wiring Guide

Shifter Connection

Pedal Connection (ADS1115)

ADS1115 Module          Raspberry Pi Pico
──────────────          ─────────────────
VDD ───────────────────> 3.3V
GND ───────────────────> GND
SDA ───────────────────> GP20
SCL ───────────────────> GP21

Potentiometer            ADS1115
───────────────────────  ───────
Pedal 1 ────────────────> A0
Pedal 2 ────────────────> A1
Pedal 3 ────────────────> A2

Button Connections

All buttons use internal pull-up resistors:

Button/Switch           Raspberry Pi Pico
─────────────          ─────────────────
One side ──────────────> GPxx (configured pin)
Other side ────────────> GND

Pressed = LOW (connected to GND)
Released = HIGH (pulled up internally)

Usage

First Time Setup

1. Upload the code to your Raspberry Pi Pico
2. Connect your hardware according to the wiring guide
3. The pedals will auto-calibrate as you use them
4. Calibration is saved to EEPROM after 60 seconds of no changes

Pedal Calibration

Automatic Calibration:

• Press each pedal fully a few times
• The min/max values are automatically learned
• Saved to EEPROM after 60 seconds

Manual Reset:

• Hold the first direct button (directButton[0]) for 10 seconds
• All pedal calibration will reset to defaults
• Release button and recalibrate by pressing pedals

Shifter Calibration

The shifter uses threshold values that you can adjust in the configuration:

• X_LEFT_THRESHOLD, X_RIGHT_THRESHOLD - Left/Center/Right positions
• Y_TOP_THRESHOLD, Y_BOTTOM_THRESHOLD - Top/Bottom positions