MCP23017 Temperature Monitor

#! /usr/bin/python

#Imports
import smbus
import sys
import getopt
import time
import os

#Set up SMBus
bus = smbus.SMBus(0)  #for revision 2 board...use 1

#Set the I2C address
address1 = 0x20
address2 = 0x21

# Set both banks to outputs
bus.write_byte_data(address1,0x00,0x00)
bus.write_byte_data(address1,0x01,0x00)
bus.write_byte_data(address2,0x00,0x00)
bus.write_byte_data(address2,0x01,0x00)

#Bank mapping
bank1 = 1 #Port A on 0x20
bank2 = 2 #Port B on 0x20
bank3 = 3 #Port A on 0x21


#More Bank Mapping
def set_led(data,bank):
  if bank == 1:
   bus.write_byte_data(address1,0x12,data) #Bank 1 = MCP port A
  if bank == 2:
   bus.write_byte_data(address1,0x13,data) #Bank 2 = MCP port B
  if bank == 3:
   bus.write_byte_data(address2,0x12,data) #Bank 3 = MCP port A (second chip)
  return

  #Clear all Segments

  set_led(0,bank1)
  set_led(0,bank2)
  set_led(0,bank3)
  time.sleep(1)

def main():

  #Define supporting variable

  timelastchecked = 0

  #Main Program

  while 1:
    if time.time() >= timelastchecked:
      timelastchecked = time.time()+3 #Check every 3 seconds
      mytemp = ""
      firstchar = ""
      secondchar = ""
      thirdchar = ""
      f=os.popen("/opt/vc/bin/vcgencmd measure_temp") #Temperature command for terminal
      for i in f.readlines():
        mytemp += i
        firstchar = mytemp[5:-6] #removes 5 characters from the front of the string, and 6 from the back
        secondchar = mytemp[6:-5] #second character string
        thirdchar = mytemp[8:-3] #third character string
        while 1: #first segment
          if firstchar == '0': #If first digit is 1
            set_led(119,bank1)
          if firstchar == '1': #If first digit is 1
            set_led(20,bank1)
          elif firstchar == '2': #if not 1, try 2
            set_led(79,bank1)
          elif firstchar == '3': #if not 2, try 3
            set_led(182,bank1)
          elif firstchar == '4': #and so on...
            set_led(212,bank1)
          elif firstchar == '5':
            set_led(230,bank1)
          elif firstchar == '6':
            set_led(231,bank1)
          elif firstchar == '7': #and so on...
            set_led(52,bank1)
          elif firstchar == '8':
            set_led(247,bank1)
          elif firstchar == '9':
            set_led(244,bank1)

          while 1: #second segment
            if secondchar == '0':
              set_led(127,bank2)
            elif secondchar == '1':
              set_led(28,bank2)
            elif secondchar == '2':
              set_led(187,bank2)
            elif secondchar == '3':
              set_led(190,bank2)
            elif secondchar == '4':
              set_led(220,bank2)
            elif secondchar == '5':
              set_led(238,bank2)
            elif secondchar == '6':
              set_led(239,bank2)
            elif secondchar == '7':
              set_led(60,bank2)
            elif secondchar == '8':
              set_led(255,bank2)
            elif secondchar == '9':
              set_led(252,bank2)

            while 1: #third segment
              if thirdchar == '0':
                set_led(119,bank3)
              elif thirdchar == '1':
                set_led(20,bank3)
              elif thirdchar == '2':
                set_led(179,bank3)
              elif thirdchar == '3':
                set_led(182,bank3)
              elif thirdchar == '4':
                set_led(212,bank3)
              elif thirdchar == '5':
                set_led(230,bank3)
              elif thirdchar == '6':
                set_led(231,bank3)
              elif thirdchar == '7':
                set_led(52,bank3)
              elif thirdchar == '8':
                set_led(247,bank3)
              elif thirdchar == '9':
                set_led(244,bank3)
              time.sleep(2)
              main()


if __name__ == "__main__":
   main()