Hardware Setup

Assemble your Donkeycar with the right components and build a functional autonomous RC vehicle

Overview

Building a Donkeycar requires assembling hardware components on an RC car chassis. This guide covers the recommended components and assembly process.

Recommended Hardware Components

Computing Platform

Raspberry Pi (Recommended)

• Raspberry Pi 4 (2GB+ RAM recommended)
• Raspberry Pi 3 B+ (minimum)
• Compatible with RaspberryPi OS
• Powers the car’s AI and control systems

The Raspberry Pi is the preferred on-board computer for Donkeycar. If you’re new to Raspberry Pi, set it up using Raspberry Pi Imager and familiarize yourself with raspi-config before building your car.

Camera Options

Donkeycar supports multiple camera types:

Raspberry Pi Camera (PICAM)

• CSI interface camera
• Low latency, reliable
• Most common choice
• Set CAMERA_TYPE = "PICAM" in config

USB Webcam

• Standard USB camera
• Easy to connect
• Set CAMERA_TYPE = "WEBCAM" in config

Advanced Options

• CSIC: High-speed CSI camera (e.g., Arducam)
• D435: Intel RealSense D435 with depth sensing
• OAKD: Luxonis OAK-D with depth and IMU
• CVCAM: OpenCV-compatible camera

Motor Controllers

PCA9685 PWM Driver (Most Common)

• 16-channel PWM controller
• I2C interface (address typically 0x40)
• Controls both steering servo and ESC (Electronic Speed Controller)
• Requires calibration of PWM pulse values

Alternative Controllers

• RoboHat MM1: Integrated controller for Raspberry Pi
• Direct PWM Pins: Using Raspberry Pi GPIO
• PiGPIO: Hardware PWM using pigpio daemon

Drive Train Types

Your configuration depends on your chassis:

Standard RC Car (PWM_STEERING_THROTTLE)

• Steering servo + ESC
• Most common setup
• Typical PWM range: 200-500 (12-bit values)

DRIVE_TRAIN_TYPE = "PWM_STEERING_THROTTLE"

Differential Drive (DC_TWO_WHEEL)

• Tank-style steering
• Two motors (left/right)
• Uses H-Bridge motor driver (L298N)

Other Options

• DC_STEER_THROTTLE: DC motor for steering
• SERVO_HBRIDGE_2PIN: Servo + 2-pin H-Bridge
• SERVO_HBRIDGE_3PIN: Servo + 3-pin H-Bridge
• VESC: VESC motor controller

Chassis

Recommended RC car platforms:

• Exceed Desert Monster: Popular choice
• Magnet 1/16 Scale Rally Car: Affordable option
• Traxxas: Higher-end, durable
• Custom 3D-printed chassis: For advanced users

Make sure your chassis has enough space for the Raspberry Pi, motor controller, and battery. A 1/10 or 1/16 scale RC car is ideal.

Additional Components

Required

• Power supply (5V for Pi, battery for motors)
• MicroSD card (16GB+ for Pi)
• Jumper wires and connectors

Optional Sensors

• IMU (Inertial Measurement Unit): MPU6050 or MPU9250
• LIDAR: RP or YD LIDAR for obstacle detection
• GPS: For path following
• Encoders: For odometry and speed measurement

Assembly Steps

Configuration Pin Mappings

Standard PWM_STEERING_THROTTLE Setup

PWM_STEERING_THROTTLE = {
    "PWM_STEERING_PIN": "PCA9685.1:40.1",   # Channel 1
    "PWM_STEERING_SCALE": 1.0,
    "PWM_STEERING_INVERTED": False,
    "PWM_THROTTLE_PIN": "PCA9685.1:40.0",   # Channel 0
    "PWM_THROTTLE_SCALE": 1.0,
    "PWM_THROTTLE_INVERTED": False,
    # Values below are set during calibration
    "STEERING_LEFT_PWM": 460,
    "STEERING_RIGHT_PWM": 290,
    "THROTTLE_FORWARD_PWM": 500,
    "THROTTLE_STOPPED_PWM": 370,
    "THROTTLE_REVERSE_PWM": 220,
}

Pin Format Explained

The pin format "PCA9685.1:40.0" means:

• PCA9685: Controller type
• 1: I2C bus number
• 40: I2C address (0x40 in hex)
• 0: Channel number (0-15)

Camera Configuration

# Camera selection
CAMERA_TYPE = "PICAM"

# Image resolution (affects processing speed)
IMAGE_W = 160
IMAGE_H = 120
IMAGE_DEPTH = 3  # RGB

# Camera orientation
CAMERA_VFLIP = False  # Vertical flip
CAMERA_HFLIP = False  # Horizontal flip

# Frame rate (should match DRIVE_LOOP_HZ)
CAMERA_FRAMERATE = 20

Verifying Your Setup

Troubleshooting

Camera not detected

• Verify cable connection to CSI port
• Enable camera in raspi-config
• Check: vcgencmd get_camera

I2C device not found

• Enable I2C in raspi-config
• Check wiring connections
• Verify 5V power to PCA9685

Motors not responding

• Check battery charge
• Verify ESC/servo connections to PCA9685
• Ensure V+ on PCA9685 is powered (5-6V)
• Test with original RC receiver first

Servo jitters or behaves erratically

• Add capacitor across PCA9685 power supply
• Check for loose connections
• Verify PWM frequency (typically 60Hz)

Next Steps

Once your hardware is assembled:

1. Create your car application with donkey createcar
2. Calibrate steering and throttle
3. Start driving and collecting data

Additional Resources

• Raspberry Pi Documentation
• PCA9685 Datasheet
• Donkeycar Discord Community