us-100 ultrasonic theremin on microbit. Uses fizban99's code to get distance.

microbit theremin

from microbit import uart, pin14, pin15, pin2, pin1, pin0, sleep, display
from sys import print_exception
import music
#This is a simplified version of the library here: 
# https://github.com/fizban99/microbit_us100
#
# TODO: Perhaps see the above for exception handling.

class US100:

    def __init__(self, tpin=pin15, rpin=pin14):
        self.tx_pin = tpin
        self.rx_pin = rpin

    def distance_mm(self):
            uart.init(baudrate=9600, bits=8, parity=None, stop=1, tx=self.tx_pin, rx=self.rx_pin)
            sleep(1)
            uart.write(b'\x55')
            t = 0
            buf = bytearray(2)
            while not uart.any() and t < 1000:
                t = t + 1
                sleep(5)
            if t < 1000:
                uart.readinto(buf, 2)
            uart.init(115200)
            dist = buf[0] * 256 + buf[1]
            if dist > 1100:
                dist = -1
            return dist

sonar=US100(pin1, pin2)
while True:
    d = sonar.distance_mm()
    music.pitch(d, -1, pin0, False)
    sleep(20)