Create ultrasonic_client.py

raspberryPi/ultrasonic_client.py

@@ -0,0 +1,62 @@
+"""
+Reference:
+Ultrasonic Distance Measurement Using Python – Part 2
+http://www.raspberrypi-spy.co.uk/2013/01/ultrasonic-distance-measurement-using-python-part-2/
+    
+"""
+
+from socket import *
+import time
+import RPi.GPIO as GPIO
+
+
+GPIO.setwarnings(False)
+
+# create a socket and bind socket to the host
+client_socket = socket(AF_INET, SOCK_STREAM)
+client_socket.connect(('192.168.1.100', 8002))
+
+def measure():
+    """
+    measure 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
+
+# referring to the pins by GPIO numbers
+GPIO.setmode(GPIO.BCM)
+
+# define pi GPIO
+GPIO_TRIGGER = 23
+GPIO_ECHO    = 24
+
+# output pin: Trigger
+GPIO.setup(GPIO_TRIGGER,GPIO.OUT)
+# input pin: Echo
+GPIO.setup(GPIO_ECHO,GPIO.IN)
+# initialize trigger pin to low
+GPIO.output(GPIO_TRIGGER, False)
+
+try:
+    while True:
+        distance = measure()
+        print "Distance : %.1f cm" % distance
+        # send data to the host every 0.5 sec
+        client_socket.send(str(distance))
+        time.sleep(0.5)
+finally:
+    client_socket.close()
+    GPIO.cleanup()