Micro Bit An Introduction

Mirobit is a device that originated with the BBC in the UK. This device is available to students in the UK for computer education. The goal is to provide an affordable way to teach students computer technology and programming.

A Micro Bit is about the size of a credit card. It measures 5 by 4 centimeters. Don't let the size fool you. It is a powerful device. At the core is a microcontroller. 

I've covered microcontrollers in previous issues. One issue covered the use of a microcontroller on the mBot to control LED lights (June 1, 2018). Another covered the use of a virtual Arduino microcontroller to control electronic components in TinkerCAD(April 30, 2018).

The microcontroller on the Micro Bit is comparable to other microcontrollers. Skills learned on the Micro Bit are applicable to other devices using similar microcontrollers. 

The Micro Bit uses a 32bit ARM processor. The processor has 16Kb of RAM. The speed is clocked at 16KHz. These specifications are much less than those of modern computers. By comparison, a typical computer has RAM measured in Gigabytes. Typical computers have 4, 8, or 16 gigabytes of RAM. Instructions are processed in the Gigahertz range. A typical computer will operate at 1.6, 2.1, or 2.7 gigahertz.

The specifications of the ARM processor remind me of my first computer. The specifications were almost the same. It was much slower with an 8-bit processor. The state of the art at the time. The goal of a microcontroller is not speed or storage. A microcontroller is designed to perform a set of repetitive tasks. 

Microcontrollers are found in almost any modern electrical device. There are microcontrollers in your watch, computer, thermostat, and car. Microcontrollers are becoming more common. They are part of devices that take advantage of IOT, Internet of Things

The Internet of Things is anything that is controllable through devices like a smartphone. An example of an IOT is a modern thermostat that is controlled by your smartphone. Devices like Alexa from Amazon control microcontrollers on devices like light bulbs. These devices interact with Alexa to receive instructions and respond to those instructions.

A closer look at the Micro Bit

The imprinted circuit board on the Micro Bit contains buttons to trigger events. It has an accelerometer and a compass. The accelerometer is used to detect motion. The campus is used to determine the orientation of the Micro Bit. Bluetooth technology is included. Bluetooth is used to communicate with other Micro Bit devices.

One side of the Micro Bit has a series of LEDs. These LEDs are arranged into rows and columns. The 25 LEDs are programmable for displaying information. The five by five grid is used to display scrolling information or simple designs. 

Programs are sent to the Micro Bit through a USB connector. The program executes each time the Micro Bit is activated or reset. New instructions must be uploaded if we want it to perform different actions. 

The Micro Bit is too small to have a battery. It does have a battery connector and USB option to supply power. The battery connector supplies 5 volts. The voltage provided by the USB is also 5 volts. The basic Micro Bit usually doesn’t include a USB cable. Kits come with a USB cable and other components. I recommend getting a kit whenever possible.

The price of the Micro Bit is very affordable. A Micro Bit starts at about $20 US dollars. It’s almost the price of some of those required school supply items. There are school sets that are priced around $150 to $200 for a set of 10. These kits contain several connectors and guides. There are a variety of resellers out there. 

Before purchasing you might want to see what the Micro Bit is all about. There is a Micro Bit simulator at microbit.org. The similar if a good way to evaluate what the Micro Bit does. Most of the functions available on the physical device are in the simulator. The simulator is a way to evaluate programs developed for the physical device. 

In this week’s issue, we use the simulator to develop a variety of projects. These projects are aimed at giving you a foundational use of the Micro Bit and coding environment. The coding environment uses the familiar block coding format.