LED screen

The BBC micro:bit LED screen consists of 25 red LED lights arranged in a 5X5 grid (5 LEDs across by 5 LEDs down).

BBC micro:bit with all 25 LEDs lit

 

Which LED?

You use x , y coordinates to specify a particular LED in the grid; where x is the horizontal position and y is the vertical position (0, 1, 2, 3, 4). To figure out the x, y coordinates, position your micro:bit horizontally, like a credit card (see picture above).

Here are the x, y coordinates for the LEDs in the 5X5 grid:

0, 0 1, 0 2, 0 3, 0 4, 0

0, 1 1, 1 2, 1 3, 1 4, 1

0, 2 1, 2 2, 2 3, 2 4, 2

0, 3 1, 3 2, 3 3, 3 4, 3

0, 4 1, 4 2, 4 3, 4 4, 4

The x, y coordinates for the LED in the centre of the grid are 2, 2. Starting from 0, 0 count over 2 columns and then down 2 rows.

Row, column - 1

Since the row and column numbers start at 0, an easy way to figure out the x, y coordinates is to subtract 1 from the row and column number (when counting from 1). In other words, to specify the LED in the 4th column 5th row, subtract 1 from each number to get coordinates 3, 4.

Coding the LEDs

JavaScript Blocks Editor

Turning a LED on/off

Use plot and unplot to turn an LED on or off.

Is a LED on/off?

Use the point function to find out if a LED is on or off.

Display images, strings and numbers

Instead of turning individual LEDs on or off, as above, you can display an image directly to the screen or show text/numbers on screen using the show number/show string function.

Python

See the images section of the documentation to learn more about programming the LEDs in Python for micro:bit.