1. Number chooser

A number chooser can be used for a variety purposes, including, sending data, via radio, to other microbits.

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1.1. Number chooser: simple version

The code below, sets a variable, num, to a starting number, 5.

When the A-button is pressed, num is increased by 1.

To make sure num doesn’t just keep increasing without limit, if it is reaches 9 when the A-button is pressed, it is reset to 0.

from microbit import *

num = 5
display.show(num)
while True:
    if button_a.is_pressed():
        num += 1
        if num > 9:
            num = 0
        display.show(num)
    sleep(200)

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1.2. Number chooser: by function

The code below chooses a number from 0 to 9. These limits are set in the select_number function.

In the main while-loop, the function, select_number, is called to choose a number, num, which is then displayed.

The function, select_number, starts the variable, counter, at 5.

The while-loop keeps running until the B-button is pressed, then the variable, counter, is returned.

In the while-loop, A-button pressing is used to increase the variable, counter, until it gets to its biggest allowed value, 9, then it restarts at 0.

from microbit import *


def select_number():
    counter = 5
    display.show(counter)
    while button_b.was_pressed() is False:
        if button_a.is_pressed():
            num += 1
            if counter > 9:
                counter = 0
            display.show(counter)
        sleep(200)
    return counter


while True:
    num = select_number()
    display.scroll(num)
    sleep(200)

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Tasks

1. Add the parameters, min_num and max_num, to the select_number function so that the numbers are not limited to 0 to 9. Test with numbers 10 to 19. Modify the initial counter value to be the average of the min_num and max_num values. Add a short delay to display.show so the counter values are shown faster.

2. Add a start_num parameter to select_number, so it looks like: select_number(start_num, min_num, max_num).

Q1

Add the parameters, min_num and max_num, to the select_number function so that the numbers are not limited to 0 to 9. Test with numbers 10 to 19. Modify the initial counter value to be the average of the min_num and max_num values. Add a short delay to display.show so the counter values are shown faster.

from microbit import *


def select_number(min_num, max_num):
    counter = int((min_num + max_num)/2)
    display.show(counter, delay=200)
    while button_b.was_pressed() is False:
        if button_a.is_pressed():
            counter += 1
            if counter > max_num:
                counter = min_num
            display.show(counter, delay=200)
        sleep(200)
    return counter


while True:
    num = select_number(10, 19)
    display.scroll(num)
    sleep(200)

Q2

Add a start_num parameter to select_number, so it looks like: select_number(start_num, min_num, max_num)

from microbit import *


def select_number(start_num, min_num, max_num):
    counter = start_num
    display.show(counter, delay=200)
    while button_b.was_pressed() is False:
        if button_a.is_pressed():
            counter += 1
            if counter > max_num:
                counter = min_num
            display.show(counter, delay=200)
        sleep(200)
    return counter


num = 14
while True:
    num = select_number(num, 10, 19)
    display.scroll(num)
    sleep(200)