servo3.py

#!/usr/bin/env python
#
# Demonstrates Servo control
#
# MUST use pin 18

import time

def setupServo():
    with open("/sys/class/pwm/pwm0/mode", "w") as f:
        f.write("servo")

def toggleServo(enabled):
    value = "0"
    if enabled:
        value = "1"

    with open("/sys/class/pwm/pwm0/active", "w") as f:
        f.write(value)


# Duty cycle can vary between 1-180
def setServoPosition(pos):
    if pos <= 0:
        pos = 1
    elif pos > 180:
        pos = 180

    with open("/sys/class/pwm/pwm0/servo", "w") as f:
        f.write(str(pos))

def servoTest():
    setupServo()
    toggleServo(True)

    while True:
        for i in range(0, 32, 1):
            print ("Servo position (degrees): ",i)
            setServoPosition(i)
            time.sleep(.2)

    toggleServo(False)

if __name__ == "__main__":
    servoTest()