The Micro Bit (also referred to as BBC Micro Bit, stylized as micro:bit) is an open source hardware ARM-based embedded system designed by the BBC for use in computer education in the UK
Micro bit board measures 43 mm × 52 mm and, in its first production run included:
- Nordic nRF51822 – 16 MHz 32-bit ARM Cortex-M0 microcontroller, 256 KB flash memory, 16 KB static RAM, 2.4 GHz Bluetooth low energy wireless networking. The ARM core has the capability to switch between 16 MHz or 32.768 kHz.NXP/Freescale KL26Z – 48 MHz ARM Cortex-M0+ core microcontroller, that includes a full-speed USB 2.0 On-The-Go (OTG) controller, used as a communication interface between USB and main Nordic microcontroller. This device also performs the voltage regulation from the USB supply (4.5-5.25 V) down to the nominal 3.3 volts used by the rest of the PCB. When running on batteries this regulator is not used.
- NXP/Freescale MMA8652 – 3-axis accelerometer sensor via I²C-bus.
- NXP/Freescale MAG3110 – 3-axis magnetometer sensor via I²C-bus (to act as a compass and metal detector).
- MicroUSB connector, battery connector, 25-pin edge connector.
- Display consisting of 25 LEDs in a 5×5 array.
- Three tactile pushbuttons (two for applications, one for reset)
I/O includes three ring connectors (plus one power one ground) which accept crocodile clips or 4 mm banana plugs as well as a 25-pin edge connector with two or three PWM outputs, six to 17 GPIO pins (depending on configuration), six analog inputs, serial I/O, SPI, and I²C.Unlike early prototypes, which had an integral battery, an external battery pack (AAA batteries) can be used to power the device as a standalone or wearable product. Health and safety concerns, as well as cost, were given as reasons for the removal of the button battery from early designs.
The available hardware design documentation consist of only the schematic and BOM distributed under the Creative Commons By Attribution license, no PCB layout is available. The compatible reference design by Micro:bit Educational Foundation, however, is fully documented.
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. With 25 red LEDs to light up, simply switch it on, code it, light it up and tell it what you want it to do. Create anything from games, animations and scrolling stories - all you need is imagination and creativity. Other features include a built-in compass, motion detector, BLE and rings to connect sensors, so you can plug the BBC micro:bit into your life.
There are two official code editors on the micro:bit foundation web site:
micro bit coding or micro bit programing
Groundbreaking initiative to inspire digital creativity and develop a new generation of tech pioneers
Board layout - front
1. Button A (left button with edge connector at the bottom) – labelled A on the board
2. Button B (right button with edge connector at the bottom) – labelled B on the board
3. P0 (left large pin (crocodile clip port) with edge connector at the bottom) - labelled 0 on the board
4. P1 (middle large pin (crocodile clip port) with edge connector at the bottom) - labelled 1 on the board
5. P2 (right large pin (crocodile clip port) with edge connector at the bottom) - labelled 2 on the board
6. +3V - labelled 3V on the board. This is 3V PWR OUT
8. P3 – P22 pins from left to right with edge connector at the bottom. Referred to as Pins when referencing that part of the board. Text will talk about 'pins' when referring to individual connections or the general way of connecting to the board – not labelled on the front of the board
9. LED matrix referred as the 'screen' - not labelled on the board
10. LED coordinates starting at 0,0 top left corner - not labelled on the board
The order of the large pins as follows: P0 P1 P2 3V GND labelled 0, 1, 2, 3V GND on the board
Board layout - back
1. USB Plug (Micro-USB plug) – labelled USB on the board
2. Button R (reset button) – labelled Reset on the board
3. Status LED – not labelled on the board
4. Battery socket – labelled Battery on the board
There are additional copper pins on the back of the board that will not be connected to anything. These are to facilitate labelling, while ensuring that a board plugged in the wrong way around doesn't damage any external accessory.
3. Bluetooth Smart Technology Antenna
4. AAA Battery Holder - not labelled on the board
5. Processor (Cortex M0)
6. P3 – P22 plus P0, P1 and P2 pins from left to right with edge connector at the bottom. Referred to as 'pins' when labelling that part of the board. Text will talk about 'pins' when referring to individual connections or the general way of connecting to the board – labelled PINS on the board
The runtime includes:
- A simple, unified OO model for the device
- A lightweight, non-pre-emptive fibre scheduler
- Managed types for immutable strings and bitmapped images
- A message bus for shipping software and hardware events (eg button presses, device in freefall, scroll text complete)
- LED matrix display driver
- A simple image manipulation library
- Electronic compass driver
- Accelerometer driver
- Button sensor
- Inference-based digital and analogue I/O abstractions
- Bluetooth Smart Technology over-the-air programing
- Bluetooth Smart Technology peripheral mode exposure of runtime components
- Capacitive sense pins
BBC micro:bit edge pinout
- Official website
- BBC micro:bit technical specifications
- hands-on with BBC's Micro Bit (original prototype)
- BBC micro:bit at Microsoft Research
- BBC micro:bit repository on GitHub
Part content from wikipedia.org