VRC-USB Adapter for Raspberry Pi Pico

This project allows you to use your RC Car transmitter and receiver as a USB Gamepad. It is designed for VRC Pro, but works with any simulator that supports standard USB joysticks.

It converts the PWM signals from an RC Receiver into a USB HID Joystick device using a Raspberry Pi Pico (RP2040).

This is a port of the original ATmega32U4 project by kekse23.de. Most of this port was completed by AI.

Features

• Plug & Play: Identifies as "VRC-USB" in Windows.

• High Performance: Uses the RP2040's PIO/Interrupt capabilities for low-latency signal reading.

• 4 Channels: Supports Steering, Throttle, and two AUX channels.

• No Drivers Needed: Uses standard HID Gamepad drivers.

Hardware Required

• Raspberry Pi Pico/Waveshare RP2040-Zero (or any RP2040 based board).

• RC Receiver (Any standard PWM receiver bound to your transmitter).

• Male Futaba style connectors (Required to connect to your receiver).

Wiring

⚠️ IMPORTANT: The Raspberry Pi Pico GPIO pins are NOT 5V tolerant. You must power your RC Receiver using the Pico's 3.3V (3V3) pin. Do NOT use the 5V (VBUS) pin to power the receiver, as the 5V signal return can damage the Pico.

Raspberry Pi Pico

Function	RC Receiver	Pico Pin	GPIO Pin
Power	Red*	3V3 (OUT)	Pin 36
Ground	Black/Brown*	GND	Any GND
Steering	Signal Ch 1	Pin 34	GPIO 28
Throttle	Signal Ch 2	Pin 5	GPIO 3
Aux 1	Signal Ch 3	Pin 6	GPIO 4
Aux 2	Signal Ch 4	Pin 7	GPIO 5

RP2040-Zero

Function	RC Receiver	Pico Pin	GPIO Pin
Power	Red*	3V3 (OUT)	Pin 3V3
Ground	Black/Brown*	GND	Any GND
Steering	Signal Ch 1	Pin 28	GPIO 28
Throttle	Signal Ch 2	Pin 3	GPIO 3
Aux 1	Signal Ch 3	Pin 4	GPIO 4
Aux 2	Signal Ch 4	Pin 5	GPIO 5

Any Pico/RP2040 should also work as long as you connect to the correct pins. If those pins dont exist on your board, you can amend the .ino file and recompile. Info below.

Note: You only need to connect power and ground once, either channel 1 or channel 2 can supply the power/ground. The other channel only needs to be signal.

Note: Most modern receivers operate perfectly on 3.3V. If your receiver strictly requires 5V to turn on, you must use a voltage divider or logic level shifter on the signal wires to protect the Pico or use the original project based on a ATmega32U4 which is 5V tolerant.

Installation

Option 1: The Easy Way (UF2 File)

1. Download the VRC_Pico.uf2 file from the Releases page.

2. Hold the BOOTSEL button on your Pico while plugging it into your computer.

3. A drive named RPI-RP2 will appear.

4. Drag and drop the .uf2 file into that drive.

5. The Pico will reboot and appear as a Game controller named VRC-USB.

Option 2: Compile from Source

If you want to modify pinouts or logic:

1. Install the Arduino IDE.

2. Add the RP2040 board manager URL in Preferences:

  https://github.com/earlephilhower/arduino-pico/releases/download/global/package\_rp2040\_index.json

3. Install "Raspberry Pi Pico/RP2040" by Earle F. Philhower via Boards Manager.

4. Select your board: Raspberry Pi Pico.

5. Important Settings:

  * USB Stack: Select "Adafruit TinyUSB". May need to install the library first.

6. Upload the VRC_Pico.ino sketch.

Configuration & Calibration

In-Game (VRC Pro)

1. Open VRC Pro.

2. Go to Options -> Control Options.

3. Click Calibrate.

4. This will load the Windows Game Controllers screen. Click Properties, then Settings and finally Calibrate

5. Following the Calibration Wizard to ensure all motion ranges are at 100%, then save.

6. Once back in VRC Pro, check that ranges use 100%. If any are reversed, you can use the 'reverse steering/throttle' option to correct, or adjust on your transmitter.