Lektion 11 - Ultraschallsensor anschließen

    
from microbit import *
from ssd1306 import draw_screen, initialize, clear_oled
from ssd1306_text import add_text
import gc

DISTANCE_CM_PER_BIT = 0.21
DISTANCE_OFFSET = 1.8

TRIG_PIN = pin0
ECHO_PIN = pin1
initialize()
clear_oled()
spi.init(baudrate=50000, bits=8, mode=0, miso=ECHO_PIN)

def distance():
    gc.disable()
    TRIG_PIN.write_digital(True)
    TRIG_PIN.write_digital(False)
    x = spi.read(200)
    high_bits = 0
    for i in range(len(x)):
        if x[i] == 0 and high_bits > 0:
            break
        elif x[i] == 0xff:
            high_bits += 8
        else:
            high_bits += bin(x[i]).count('1')    
    x = None
    gc.enable()
    gc.collect()
    return high_bits * DISTANCE_CM_PER_BIT + DISTANCE_OFFSET

while True:
    dist = distance()
    print(str(dist))
    add_text(2, 1, "Distanz: ")
    add_text(2, 3, str(dist))
    draw_screen()
    sleep(1000)