import RPi.GPIO as GPIO   # Import the GPIO library.
import time               # Import time library
from gpiozero import CPUTemperature


GPIO.setmode(GPIO.BCM)  # Set Pi to use pin number when referencing GPIO pins.
                          # Can use GPIO.setmode(GPIO.BCM) instead to use
                          # Broadcom SOC channel names.

GPIO.setup(2, GPIO.OUT)  # Set GPIO pin 2 to output mode.
pwm = GPIO.PWM(2, 50)   # Initialize PWM on pwmPin 50Hz frequency

# main loop of program

cpu = CPUTemperature()
print(cpu.temperature)



print("\nPress Ctl C to quit program \n")  # Print blank line before and after message.
dc=0                               # set dc variable to 0 for 0%
pwm.start(dc)                      # Start PWM with 0% duty cycle

try:
  while True:                      # Loop until Ctl C is pressed to stop.
    if (cpu.temperature > 75):
      dc = (((cpu.temperature - 75)*14)+30)
    if dc > 100:
        dc = 100
    if (cpu.temperature < 70):
      dc = 0
    pwm.ChangeDutyCycle(dc)
    time.sleep(2.0)             # wait 2 seconds
#    print(dc," PWM")
#    print(cpu.temperature," C")
except KeyboardInterrupt:
  print("Ctl C pressed - ending program")

pwm.stop()                         # stop PWM
GPIO.cleanup()                     # resets GPIO ports used back to input mode