The BBC micro:bit

The BBC micro:bit is a pocket-sized computer that you can code, customise and control to bring your digital ideas, games and apps to life.

Published: 6 July 2015

Measuring 4cm by 5cm, and designed to be fun and easy to use, users can create anything from games and animations to scrolling stories at school, at home and on the go - all you need is imagination and creativity.

The BBC micro:bit is completely programmable. That means each of its LEDS can be individually programmed as can its buttons, inputs and outputs, accelerometer, magnetometer and Bluetooth Smart Technology.

  • Size: approx. 5cm x 4cm
  • Weight: 8g
  • Microprocessor: 32-bit ARM® Cortex™ M0 CPU
  • A 5x5 LED matrix with 25 red LEDs to light up. Each LED is individually programmable and can display animated patterns, scrolling text and alphanumeric characters
  • Two programmable buttons. The micro:bit can detect either of its two buttons being pressed and unpressed, and can be programmed to act on that or send the information to another device. Use them as a games controller, or control music on a smartphone.
  • On-board motion detector or 3-AXIS digital accelerometer that can detect movement and tell other devices you’re on the go. It measures on 3 axes, X, Y, Z, and sends back the data in milli-gs. The micro:bit can react to this data and tell other devices it is moving. The device will also detect a small number of standard actions, eg shake, tilt and freefall. Turn the micro:bit into a spirit level. Use it for motion-activated games. Have your micro:bit light up when something is moved.
  • A built-in compass, 3D magnetometer to sense which direction you’re facing and your movement in degrees. This data can be used by the micro:bit in a program or be sent to another device. The magnetometer could also detect the presence of certain metals and magnets.
  • Bluetooth® Smart Technology (previously called Bluetooth Low Energy) to wirelessly communicate with other Bluetooth Smart devices and exchange data and commands. Connect the micro:bit to other micro:bits, devices, phones, tablets, cameras and everyday objects all around. Play games, share creations or join forces to create multi-micro:bit masterpieces. Take a selfie. Pause a DVD or control your playlist.
  • Five Ring Input and Output (I/O) including power (PWR) and ground (GRD). PWR, GRD, I/O x 3. Each I/O ring is programmable to be either analogue or digital. The rings are suitable for crocodile clips or 4mm banana plugs, meaning an external sensor can be connected to measure things like temperature, moisture, proximity to other devices. The micro:bit reads values from the sensor and acts on them or sends them to another device. The micro:bit can also send control commands to the rings – these could be used to control things like a motor or robot. The PWR and GRD rings supply 3 volts and could be used to power a separate device.
  • Edge Connector: 20 pins, 1.27mm pitch and extend 7.62mm from board edge suitable for standard connectors. This allows the micro:bit to be connected to another device, eg Arduino, Galileo, Kano and Raspberry Pi through a standard connector.
  • Micro-USB contoller: This is controlled by a separate processor and presents the micro:bit to a computer as a memory stick. This means the program can be dragged onto the micro:bit in the same way a file is dragged onto a memory stick.
  • 2xAAA battery pack
  • System LED x 1 (yellow)
  • System push button switch x 1

The BBC micro:bit is programmed through a web-based editing environment. This environment supplies various editors on which to write programs, and saves those programs to be retrieved later. The editors will support Microsoft’s Touch Develop language, JavaScript, Python, C++ and Blocks (a visual programming language). The user writes the programs for the micro:bit in their preferred language and these are sent to a server that ‘compiles’ them into the code the micro:bit understands. This is then downloaded to the user to easily drop onto the micro:bit. The web-based environment can also be used on a smartphone and tablet. When using a Bluetooth Smart Technology enabled smartphone or tablet the program can be ‘flashed’ onto the micro:bit over Bluetooth Smart Technology.

Once programmed, the BBC micro:bit operates on its own using the battery. However, it can also operate in what is called a tethered mode. When attached to another computer – for example a laptop, Raspberry Pi, smartphone or tablet – the micro:bit can be used as an external device by that computer. So it can be turned on and off, any sensors attached to it can be read and written to and messages can be displayed on it.

The BBC micro:bit can also control things happening on those devices, for example play, pause or stop a video player. The micro:bit can be ‘tethered’ either through the USB via a cable or using Bluetooth Smart Technology. Using Bluetooth Smart Technology, the connection is wireless and the micro:bit uses a special set of services written for it. All of these actions and Bluetooth Smart services can be programmed by the user through the editors. In its tethered mode, the micro:bit can be attached to the internet through the device it is tethered to. This means the micro:bit can use web-based services and communicate to other devices across the internet. In this way, the micro:bit is an Internet of Things device; it can, with permission,  communicate to other Internet of Things objects and share data and can control and be controlled by those other devices.