Display¶

The micro:bit display is a 5 × 5 grid of red LEDs that can show text, numbers, images and individual pixels at 10 brightness levels.

Possible uses:

• messages and scores
• sensor readings
• icons
• simple animations

Connect it¶

The display is built into the micro:bit, so we don't need to connect anything.

• Each example is a main.py file. See Your First Program for how to create, upload and run it.
• Pixels are located by (x, y) coordinates. (0, 0) is the top left and (4, 4) is the bottom right.
• Brightness goes from 0 (off) to 9 (brightest).

Set it up¶

The display is part of the microbit library. We import it at the top of every program:

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from microbit import *

Methods¶

display.scroll()¶

Scrolls text across the display from right to left.

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from microbit import *

# Main loop
while True:
    display.scroll("Hello world!")

display.show() — text and numbers¶

Shows characters one at a time instead of scrolling them.

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from microbit import *

# Main loop
while True:
    display.show(3.14159)

display.show() — images¶

The micro:bit has a range of built-in images, such as Image.HEART, Image.HAPPY and Image.ARROW_N.

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from microbit import *

# Main loop
while True:
    display.show(Image.HEART)

Image() — custom images¶

Make your own image with a string of 25 brightness values: five rows of five digits, with each row ending in a colon (:).

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from microbit import *

# Setup
boat = Image("05050:"
             "05050:"
             "05050:"
             "99999:"
             "09990")

# Main loop
while True:
    display.show(boat)

display.clear()¶

Turns every pixel off.

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from microbit import *

# Main loop
while True:
    display.show(Image.YES)
    sleep(1000)
    display.clear()
    sleep(1000)

display.set_pixel()¶

Sets the brightness of a single pixel.

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from microbit import *

# Main loop
while True:
    display.set_pixel(2, 2, 9)

display.get_pixel()¶

Reads the brightness of a single pixel.

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from microbit import *

# Setup
display.set_pixel(2, 2, 5)

# Main loop
while True:
    print(display.get_pixel(2, 2))
    sleep(1000)

display.off() and display.on()¶

Turns the whole display off and back on. The image is remembered while the display is off.

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from microbit import *

# Setup
display.show(Image.HAPPY)

# Main loop
while True:
    display.off()
    sleep(1000)
    display.on()
    sleep(1000)

display.is_on()¶

Checks whether the display is on.

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from microbit import *

# Main loop
while True:
    print(display.is_on())
    sleep(1000)

Documentation¶

Documentation is the official guide written by the people who made the code library, and we can use it to look up every method and its parameters, including ones that aren't covered on this page.

• BBC micro:bit MicroPython — display
• BBC micro:bit MicroPython — Image

Exercises¶

Starter files are in the display folder of your tutorial files. Solutions are on the Exercise Solutions page.

Exercise 1¶

Starter: display/ex1_show_message

Can you make it show a different message? For example:

Exercise 2¶

Starter: display/ex2_show_delay

Can you change the time between each character? For example:

Exercise 3¶

Starter: display/ex3_show_no_loop

Using the display.show() parameters in the methods table, can you show the same message repeatedly without the while True loop? For example:

Exercise 4¶

Starter: display/ex4_heartbeat

Can you change the animation so it looks more like an actual heartbeat? For example:

Exercise 5¶

Starter: display/ex5_clock

Can you use the built-in images to show a clock face moving from 1 o'clock to 12 o'clock? For example:

Exercise 6¶

Starter: display/ex6_spinning_square

Can you use the built-in images to show a spinning square? For example:

Exercise 7¶

Starter: display/ex7_no_sleep

The starter code lights each pixel in turn, down each column. What happens if you remove sleep(50)? Why do you think this happens?

Exercise 8¶

Starter: display/ex8_rows

The starter code moves a pixel down each column. Can you change it so the pixel moves across the rows instead? For example:

Exercise 9¶

Starter: display/ex9_glasses

Can you create this smiley face with glasses? Custom images using Image() will help.