import smbus
import time
import RPi.GPIO as GPIO

#IO 
PWM_PIN  = 14
PWM_FREQ = 50
I2C_ADDR = 0x48

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)
GPIO.setup(PWM_PIN, GPIO.OUT)

pwm = GPIO.PWM(PWM_PIN, PWM_FREQ)
pwm.start(0)

bus = smbus.SMBus(1)
data_log = open("data_log.txt","w") 

try:
  for dc in range(0, 100, 1):
    pwm.ChangeDutyCycle(dc)

    # ADC 0
    bus.write_byte(I2C_ADDR, 0x40)
    bus.read_byte(I2C_ADDR)
    data = bus.read_byte(I2C_ADDR)

    outputString = str(dc) + "," + str(data) + "\n"
    print outputString

    data_log.write( outputString )

    time.sleep(1)

  data_log.close()

except KeyboardInterrupt:
	pass
pwm.stop()
GPIO.cleanup()