The rotary potentiometer in middle of the board is connected to pin 0. It shares this connection with the buzzer. You have to be a little careful when using them both in the same project but, as long as you separate their use in your programs, you can do it.
The potentiometer centres with a little click and reads from 1 to 851 for me.
This first, simple program shows how to read from the potentiometer. You can view the output in the REPL window.
from microbit import * while True: reading = pin0.read_analog() print(reading) sleep(50)
There are marks on the silkscreen of the board. If you sample the readings at each of these marks, you can work out a program for a pretty exact mapping. If you allow some tolerance, +-5 or 10, you can make it easy for your user.
A quick way to map the potentiometer reading to a smaller range is to divide. This one lets you pick out all of the different positions on the clock. That makes for a selection of 0 to 11.
from microbit import * clocks = [ Image.CLOCK12,Image.CLOCK1,Image.CLOCK2, Image.CLOCK3,Image.CLOCK4,Image.CLOCK5, Image.CLOCK6,Image.CLOCK7,Image.CLOCK8, Image.CLOCK9,Image.CLOCK10,Image.CLOCK11] # set pin8 to LOW for potentiometer pin8.write_digital(0) while True: reading = pin0.read_analog()//72 display.show(clocks[reading]) sleep(50)
This program uses the same principle as the last, except it lights up a number of the Neopixels according to the dial position.
from microbit import * import neopixel # Initialise neopixels npix = neopixel.NeoPixel(pin13, 6) red = (64,0,0) off = (0,0,0) # set pin8 to LOW for potentiometer pin8.write_digital(0) while True: reading = pin0.read_analog()//123 for pix in range(0, len(npix)): if pix<reading: npix[pix] = red else: npix[pix] = off npix.show() sleep(20)
A useful next task would be to take readings at the positions indicated on the board and work out some base codes to convert each one to a number from 0 to 6 (using zero for the min and 6 for the max positions). That would make a much improved version of the last program and a basis for using the potentiometer in future projects.