servo.py

####################################################################
#
#   Copyright (c) 2013 MADE-BCN
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####################################################################

import time
import urllib2

##################################################
#   Utility functions to access the PWM mode on
#   pin 18 of the raspberry pi
##################################################
def set(prop, value):
    try:
        f = open("/sys/class/rpi-pwm/pwm0/" + prop, 'w')
        f.write(value)
        f.close()
    except:
        print("Error writing to: " + prop + " value: " + value)

def setServo(angle):
    set("servo", str(angle))

##################################################
#   Basic camera controller
##################################################
class CameraController():

    print "Camera Controller started."

    isLeaf = 1

    TICK = 6 # minimum degree of movement for servo.
    HOME = 90 # HOME position of the servo.

    position = HOME
    percentage = 50

    print "initial position: ", position, type(position)

    set("delayed", "0")
    set("mode", "servo")
    set("servo_max", "180")
    set("active", "1")
    setServo(position)

    newPosition = int(urllib2.urlopen("http://geekfreak.com:8080/").read())

    if newPosition < 0:
        newPosition = 0

    if newPosition > 180:
         newPosition = 180

    position = newPosition
    percentage = 100 - (100 * float(position)/float(180))
        
    print position
    setServo(position)