Tag:

Micropython

Micro:bit compass example in micropython

by shedboy71 26th September 2016

The micro:bit also has a compass (magnetometer)

The compass has to be calibrated before it can give accurate readings. Calibration involves moving a dot to make a circle on the matrix. Once this is complete you get a smiling face image displayed to show you that you have successfully completed the calibration.

Again you will need to click on the REPL button in the mu editor prior to flashing the micro:bit

Move the Micro:bit about and you should see different values in the console, 0 is equivalent to North

Code

[codesyntax lang=”python”]

from microbit import *

compass.calibrate()
while True:
    bearing = compass.heading()
    print(bearing)
    sleep(100)

[/codesyntax]

Further Ideas

As part of an experiment you could use the display object to display one of the corresponding images

Image.ARROW_N, Image.ARROW_NE, Image.ARROW_E, Image.ARROW_SE, Image.ARROW_S, Image.ARROW_SW, Image.ARROW_W, Image.ARROW_NW

Python

Micro:bit accelerometer Micropython example

by shedboy71 26th September 2016

The micro:bit has an accelerometer on board, you can see this in the picture below

microbit

When you flash the program, you should see a reading of the accelerometer x axis being printed at the bottom of the Mu application. You can move the Micro:bit around and the values should change

Code

[codesyntax lang=”python”]

from microbit import *

while True:
    x = accelerometer.get_x()
    print(x)
    sleep(1000)

[/codesyntax]

You can also use the get_y and get_z() methods to find out the readings on the other axes. here is an example showing this

[codesyntax lang=”python”]

from microbit import *
while True:
x = accelerometer.get_x()
y = accelerometer.get_y()
z = accelerometer.get_z()
print (“x: ” + str(x) + ” y: ” + str(y) + ” z: “+ str(z))
sleep(1000)

[/codesyntax]

Python

Random image on the Micro:bit using Micropython

by shedboy71 26th September 2016

The Image class also has the following built-in instances of itself included as its attributes (the attribute names indicate what the image represents). In this example we will randomly display an image on the led matrix when the button a is pressed

Code

[codesyntax lang=”python”]

from microbit import *

import random

image_array = [Image.HEART, Image.HEART_SMALL, Image.HAPPY, Image.SMILE, Image.SAD,
Image.CONFUSED, Image.ANGRY, Image.ASLEEP, Image.SURPRISED, Image.SILLY, Image.FABULOUS,
Image.MEH, Image.YES, Image.NO, Image.CLOCK12, Image.CLOCK11, Image.CLOCK10, Image.CLOCK9,
Image.CLOCK8, Image.CLOCK7, Image.CLOCK6, Image.CLOCK5, Image.CLOCK4, Image.CLOCK3,
Image.CLOCK2, Image.CLOCK1, Image.ARROW_N, Image.ARROW_NE, Image.ARROW_E, Image.ARROW_SE,
Image.ARROW_S, Image.ARROW_SW, Image.ARROW_W, Image.ARROW_NW, Image.TRIANGLE,
Image.TRIANGLE_LEFT, Image.CHESSBOARD, Image.DIAMOND, Image.DIAMOND_SMALL, Image.SQUARE,
Image.SQUARE_SMALL, Image.RABBIT, Image.COW, Image.MUSIC_CROTCHET, Image.MUSIC_QUAVER,
Image.MUSIC_QUAVERS, Image.PITCHFORK, Image.XMAS, Image.PACMAN, Image.TARGET, Image.TSHIRT,
Image.ROLLERSKATE, Image.DUCK, Image.HOUSE, Image.TORTOISE,Image.BUTTERFLY,
Image.STICKFIGURE, Image.GHOST, Image.SWORD, Image.GIRAFFE, Image.SKULL,
Image.UMBRELLA, Image.SNAKE]

while True:
    if button_a.is_pressed():
        display.show(random.choice(image_array))
        sleep(1000)
    else:
        display.clear()

[/codesyntax]

Python

Image examples for the Micro:bit using Micropython

by shedboy71 26th September 2016

Here we show you how to create a custom image on the led matrix, we use the Mu editor – http://codewith.mu/

[codesyntax lang=”python”]

from microbit import *
im = Image(‘99999:90009:90009:90009:99999:’)
display.show(im)

[/codesyntax]

You can vary the brightness by changing the value of the digits from 0 – 9.

[codesyntax lang=”python”]

from microbit import *
im = Image(‘99999:96369:96369:96369:99999:’)
display.show(im)

[/codesyntax]

A simple animation example

[codesyntax lang=”python”]

from microbit import *

imgs = [
Image(‘90000:00000:00000:00000:00000:’),
Image(‘00000:09000:00000:00000:00000:’),
Image(‘00000:00000:00900:00000:00000:’),
Image(‘00000:00000:00000:00090:00000:’),
Image(‘00000:00000:00000:00000:00009:’)
]

display.show(imgs, delay=1000,loop=True)

[/codesyntax]
You can also set a pixel and move it around

[codesyntax lang=”python”]

from microbit import *

img = Image('00000:00000:00900:00000:00000:')
display.show(img)
sleep(1000)

while True:
img = img.shift_up(2)
display.show(img)
sleep(1000)
img = img.shift_right(2)
display.show(img)
sleep(1000)
img = img.shift_down(2)
display.show(img)
sleep(1000)
img = img.shift_left(2)
display.show(img)
sleep(1000)

[/codesyntax]
shift_left(n)

Return a new image created by shifting the picture left by n columns.

shift_right(n)

Same as image.shift_left(-n).

shift_up(n)

Return a new image created by shifting the picture up by n rows.

shift_down(n)

Same as image.shift_up(-n).