RasPiRobot Board V2: Expand Your Raspberry Pi Into a Powerful Robot Controller

Compatible with Raspberry Pi 2 and later models.

The RasPiRobot Board V2 is a ready‑to‑use expansion board that transforms your Raspberry Pi into a fully‑featured robotic controller. Sold fully assembled, it includes a switch‑mode power supply, allowing you to power the Pi and your robot from a variety of battery packs.

Mounting directly onto the Pi’s GPIO header, the board offers bi‑directional control of two DC motors via an L293D H‑bridge driver and independent PWM speed control for each motor. Its integrated 5 V/2 A supply lets you run a fully loaded Raspberry Pi and motors from a 6‑cell AA battery pack (battery not included).

Where to Buy

In the United States, the RasPiRobot Board is available from Adafruit for $29.95. In the United Kingdom and worldwide, Seedstudio offers it for approximately £15 (prices vary with exchange rates). It is also available on Amazon.co.uk for £17.50.

Key Features

• Compatible with Raspberry Pi models A, A+, B, and B+.
• Open‑source hardware design.
• Comprehensive open‑source Python library with examples – available on GitHub: raspirobot.com.
• Fully assembled – no soldering required.
• Bi‑directional control of two motors.
• Variable PWM power control – independently adjust motor speed and use lower‑voltage motors.
• Integrated switch‑mode power supply: delivers up to 2 A at 5 V, enabling operation from 6 × AA batteries.
• Dedicated range‑finder header for HC‑SR‑04 ultrasonic sensors.
• 5 V I²C header, pin‑compatible with Adafruit displays.
• Two buffered open‑collector outputs.
• Two status LEDs.
• Two push‑button inputs.
• Screw terminals for motors and battery.
• Through‑headers exposing all GPIO pins.

Documentation

The RRB2 builds on feedback from its predecessor to deliver improved reliability and usability.

How It Works

The board is powered by a 6 V–12 V DC battery pack. While 4 × AA batteries can theoretically supply 6 V, battery voltage often drops quickly; therefore we recommend at least 6 × AA batteries (rechargeable or heavy‑duty) or a 7.2 V LiPo pack.

The RRB2 supplies 5 V at up to 2 A directly to the Raspberry Pi and the motors, eliminating the need for an external power supply.

Most 6 V motors will operate reliably at 5 V.

Installing the Python Libraries

On your Raspberry Pi, run the following commands from a terminal:

$ wget https://github.com/simonmonk/raspirobotboard2/raw/master/python/dist/rrb2-1.1.tar.gz
$ tar -xzf rrb2-1.1.tar.gz
$ cd rrb2-1.1
$ sudo python setup.py install

Connect the RRB2 to your Pi first. For initial testing you can power the board via the Pi’s USB power connector; no batteries or motors are required at this stage.

Open a Python 2 console (Python 3 is not supported) with sudo python and execute the following commands to verify the board’s LEDs and switch:

from rrb2 import *
rr = RRB2()
rr.set_led1(1)
rr.set_led1(0)
rr.set_led2(1)
rr.set_led2(0)
rr.sw1_closed()

The last line should return False because no switch is connected.

Connecting a Battery and Motors

To build a mobile robot, pair the RRB2 with a chassis such as the Magician Chassis (widely available on eBay) or a comparable low‑cost kit. These kits typically provide a laser‑cut frame, gear motors, a battery box, and mounting hardware.

After assembling the chassis, secure the Raspberry Pi and the RRB2 on the frame. The motor leads should be routed to the L and R screw terminals; reversing the leads will reverse motor direction, so double‑check the wiring.

Important: Do not power the Raspberry Pi from both the battery pack and the USB power connector simultaneously; choose one source only.

Leave the wheels off during initial setup to prevent unintended movement. When you connect the battery pack to the third pair of screw terminals (+V outside), the Pi’s power LED should illuminate, and the RRB2 LEDs will light as well.

For wireless control, consider adding a USB Wi‑Fi dongle to enable SSH access over your network.

API Reference

The library provides an RRB2 class. All Python scripts that import this library must be executed with super‑user privileges. For detailed usage, refer to the official documentation.