#!/usr/bin/python
# -*- coding: utf-8 -*-

import pigpio
import time
import random

SERVO_X = 18 # GPIO
START_V = 500 # us
END_V = 2400 # us

def get_pulsewidth(ang):
    ang += 90.0
    if ang < 0.0:
        ang = 0.0
    if ang > 180.0:
        ang = 180.0
    w = (END_V - START_V) * (float(ang) / 180.0) + START_V
    return w

pi1 = pigpio.pi()

try:
    old_ang = 0
    for i in range(10):
        while True:
            ang = random.randint(0, 18) * 10 - 90
            if ang != old_ang:
                break

        w = get_pulsewidth(ang)
        print "ang = %f , pulse width = %f" % (ang, w)
        pi1.set_servo_pulsewidth(SERVO_X, w)
        time.sleep(0.4)
        pi1.set_servo_pulsewidth(SERVO_X, 0)
        time.sleep(0.1)
        old_ang = ang

except KeyboardInterrupt:
    pass

time.sleep(1)
pi1.set_servo_pulsewidth(SERVO_X, get_pulsewidth(0))
time.sleep(0.5)
pi1.set_servo_pulsewidth(SERVO_X, 0)
time.sleep(1)
print "Done."
pi1.stop()