Raspberry Pi

Raspberry Pi
 is a Linux-based computer at the amazing price of about £28 or 35 Euros for the Pi 3 model B. It's not quite as fast as more typical desktop computers but has good graphics. 

There are several models of Raspberry Pi, the most recent as of September 2016 being the Pi 3 Model B which has the following characteristics:
  • A 1.2GHz 64-bit quad-core ARMv8 CPU
  • 802.11n Wireless LAN
  • Bluetooth 4.1
  • Bluetooth Low Energy (BLE)
  • 1GB RAM
  • 4 USB ports
  • 40 GPIO pins
  • Full HDMI port
  • Ethernet port
  • Combined 3.5mm audio jack and composite video
  • Camera interface (CSI)
  • Display interface (DSI)
  • Micro SD card slot (now push-pull rather than push-push)
  • VideoCore IV 3D graphics core
Here are some links to sites and videos that explore the Pi but which are not robot-oriented:

Robotics with the Raspberry Pi

Before we go any further let me point out that the Arduino microcontroller board (not a micro computer like the Pi) has been around for a long time and uses less power than the Pi and so is also a possible choice for robots that do not need the additional computing power that the the Pi can provide.

The Pi certainly has the potential to be incorporated into a robot due to its size and input/output connectors. A board called the Gertboard (about £30 as a kit that you need to solder) expands the Pi's limited connectivity to the physical world, allowing for motor control, use of sensors etc. and also protects the Pi from damage. See http://www.raspberrypi.org/archives/1734.

The GrovePi board allows the Arduino Grove sensors (there are more than 100 different kinds) to be used with the Pi.

Visit my Python robotics page and read about the BrickPi and PiStorms shields that allows the Raspberry Pi to connect (via the shield) to Lego EV3 motor and sensors. BrickPi can be used with Python, Scratch or C.

GoPiGo is a cheap Raspberry Pi robot available for $85 HERE (does not include the Raspberry Pi). This is the robot kit I chose to buy or my first Pi robotics experiments because it has compatibility with the Pi camera (not included), it uses encoders to get feedback on the rotation of the wheels and its controller board seems to have decent expansion potential. The kit uses normal DC motors - I would have preferred a kit with servo motors. 

Pi2Go and Pi2Go-Lite are more cheap Raspberry Pi robots - just £30* for the Lite version HERE with soldering needed or £40* with the soldering done for you (not including the Pi). (* not including VAT)

Then there is the Pizazz at £28* not including batteries or the Pi.

The Initio is a larger, tougher Raspberry Pi powered robot at £78* not including batteries or the Pi.

ModMyPi.com is a good UK-based site for all things Pi.

Piborg.org (UK based) specialises in add-on boards for the Raspberry Pi and they also make the Diddyborg which  they claim is the most powerful robot available for the Pi. It should be, for the kit costs £180!

The Laika platform allows control of motors, switches, lamps, robots and more using Scratch, Python or C on your Raspberry Pi. The Laika requires external power, and a USB cable to connect to the Pi and a pack containing all these items (except the Pi) can be bought for £40 HERE. This kit enables the use of a single power source for your Raspberry Pi, the Laika system and any motors or other external requirement!

PI2GO-LITE is a fully integrated robot kit for Raspberry Pi. It costs just £30 but requires soldering. It includes:
  • 5V switching regulator that can supply a fully loaded Pi as well as all the motors etc. on the Pi2Go
  • 2 DC motors with high 120:1 gear ratio providing more controllable drive than the standard 48:1 gear ratio motors
  • 2 x IR Obstacle sensors with indicator LEDs – detect objects within 10cm
  • 2 x IR line sensors with indicator LEDs - program the Pi2Go to follow lines
  • Ultrasonic distance sensor - measure the distance to objects in front
  • Push button – non-dedicated switch use in you programs to change mode, switch off, or whatever you want
  • 2 pairs of white LEDs - can use software PWM to vary the brightness
  • 2 servo outputs - useful for driving the add on Pan/Tilt assembly

The Tiddlybot is based on the Raspberry Pi (see above) to which it adds robot powers like movement, a multi-colored light, and line-drawing and following. This can be used to help learn and teach programming as well as for playing games. The software allows things to work out the box.  Connect to any smartphone, tablet or PC then remote control Tiddles or program with the customised Blockly Interface.
The PiBot team seems to be responsible for the launch of the TiddlyBot above but PiBot has its own site with a useful guide to Raspberry Pi Robotics.