FindDistance.py 文件源码

def get_distance(self):

        # clear trigger
        gpio.output(self.trigger, False)
        time.sleep(0.1)

        print('checking.....')
        # send pulse to trigger
        gpio.output(self.trigger, True)
        time.sleep(0.00001)
        gpio.output(self.trigger, False)


        # check echo for return signal
        while gpio.input(self.echo) == 0:
            self.pulse_start = time.time()

        while gpio.input(self.echo) == 1:
            self.pulse_end = time.time()

        pulse_duration = self.pulse_end - self.pulse_start
        distance = self.speed_of_sound / 2. * pulse_duration
        distance = round(distance, 2)
        distance /= 2.54    # inches

        # filter out things far away
        if distance > self.max_distance:
            distance = self.max_distance

        # filter out junk
        if distance < self.min_distance:
            disance = self.min_distance

        return distance