Ultraschallsensor

# Pins for ultrasonic sensor
trigger = Pin(3, Pin.OUT) # to trigger a sound impulse
echo = Pin(4, Pin.IN) # records the echo of the trigger pulse

 

## Read the distance of object in front of the robot with the ultrasonic sensor. Distance is returned in cm.
def ultra():
    distance = 0
    timepassed = 0
    signalon = 0
    signaloff = 0
    trigger.low()
    utime.sleep_us(2)
    trigger.high()
    utime.sleep_us(5)
    trigger.low()
    while echo.value() == 0:
        signaloff = utime.ticks_us()
    while echo.value() == 1:
        signalon = utime.ticks_us()
    timepassed = signalon - signaloff
    distance = round((timepassed * 0.0343) / 2, 2)
    # print("The distance from object is ", distance, "cm")
    utime.sleep_ms(100) # Wait necessary or program halts
    return distance