樹莓派超音波測距 = Raspberry + Ultrasonic HC-SR04 + MotoPiduino

一. 使用材料:
       1. Raspberry Pi
       2. MotoPiduino
       3. 超音波 HC-SR04
       4. S4A IO Board (option)

二. 接線:
      1. 把 HC-SR04 接到 MotoPiduino D10 及 D11 位置, (樹莓派 GPIO8(TRIGGER) 和 GPIO10(ECHO) 位置)
       或
      直接接到 S4A IO Board 的 D10 D11孔位

三. 接線方式如圖:
     
      

4. 編寫程式:

# -----------------------

# Import required Python libraries

# -----------------------

import time

import RPi.GPIO as GPIO

# -----------------------

# Define some functions

# -----------------------

def measure():

  # This function measures a distance

  GPIO.output(GPIO_TRIGGER, True)

  time.sleep(0.00001)

  GPIO.output(GPIO_TRIGGER, False)

  start = time.time()

  

  while GPIO.input(GPIO_ECHO)==0:

    start = time.time()

  while GPIO.input(GPIO_ECHO)==1:

    stop = time.time()

  elapsed = stop-start

  distance = (elapsed * 34300)/2

  return distance

def measure_average():

  # This function takes 3 measurements and

  # returns the average.

  distance1=measure()

  time.sleep(0.1)

  distance2=measure()

  time.sleep(0.1)

  distance3=measure()

  distance = distance1 + distance2 + distance3

  distance = distance / 3

  return distance

# -----------------------

# Main Script

# -----------------------

# Use BCM GPIO references

# instead of physical pin numbers

GPIO.setmode(GPIO.BCM)

# Define GPIO to use on Pi

GPIO_TRIGGER = 8

GPIO_ECHO    = 10

print "Ultrasonic Measurement"

# Set pins as output and input

GPIO.setup(GPIO_TRIGGER,GPIO.OUT)  # Trigger

GPIO.setup(GPIO_ECHO,GPIO.IN)      # Echo

# Set trigger to False (Low)

GPIO.output(GPIO_TRIGGER, False)

try:

  while True:

    distance = measure_average()

    print "Distance : %.1f" % distance

    time.sleep(1)

except KeyboardInterrupt:

  # User pressed CTRL-C

  # Reset GPIO settings

  GPIO.cleanup()

五. 相關資訊:

相關資訊: http://motoduino.com