from: http://www.geekfan.net/6317/ && https://www.dropbox.com/s/e04v8vnus1hwrm0/rpy_cpu_gpu_temp.py

rpy_cpu_gpu_temp.py

# Rollcode.com  
import commands 
import os   
import RPi.GPIO as GPIO  
import time  
    
LCD_RS = 25
LCD_E  = 24
LCD_D4 = 23 
LCD_D5 = 17
LCD_D6 = 18
LCD_D7 = 22
    
LCD_WIDTH = 16 
LCD_CHR = True
LCD_CMD = False
    
LCD_LINE_1 = 0x80
LCD_LINE_2 = 0xC0 
    
E_PULSE = 0.00005
E_DELAY = 0.00005
  
def get_cpu_temp(): 
    tempFile = open( "/sys/class/thermal/thermal_zone0/temp" ) 
    cpu_temp = tempFile.read() 
    tempFile.close() 
    return float(cpu_temp)/1000
    # Uncomment the next line if you want the temp in Fahrenheit 
    #return (1.8*cpu_temp)+32 
  
def get_gpu_temp(): 
    gpu_temp = commands.getoutput( '/opt/vc/bin/vcgencmd measure_temp' ).replace( 'temp=', '' ).replace( '\'C', '' ) 
    return  float(gpu_temp) 
    # Uncomment the next line if you want the temp in Fahrenheit 
    # return (1.8* gpu_temp)+32 
  
def main():   
       
    GPIO.setmode(GPIO.BCM)          
    GPIO.setup(LCD_E, GPIO.OUT)     
    GPIO.setup(LCD_RS, GPIO.OUT)    
    GPIO.setup(LCD_D4, GPIO.OUT)    
    GPIO.setup(LCD_D5, GPIO.OUT)    
    GPIO.setup(LCD_D6, GPIO.OUT)    
    GPIO.setup(LCD_D7, GPIO.OUT)    
       
    lcd_init()   
       
    # Here we show the message on the LCD screen   
    
    str_cpu = str(round(get_cpu_temp(), 2)) 
    str_gpu = str(get_gpu_temp()) 
      
    lcd_byte(LCD_LINE_1, LCD_CMD)   
    lcd_string("CPU: " + str_cpu + " C",1)   
    lcd_byte(LCD_LINE_2, LCD_CMD)   
    lcd_string("GPU: " + str_gpu + " C",1)   
       
def lcd_init():   
    lcd_byte(0x33,LCD_CMD)   
    lcd_byte(0x32,LCD_CMD)   
    lcd_byte(0x28,LCD_CMD)   
    lcd_byte(0x0C,LCD_CMD)     
    lcd_byte(0x06,LCD_CMD)   
    lcd_byte(0x01,LCD_CMD)     
       
def lcd_string(message,style):   
    # Send string to display   
    # style=1 Left justified   
    # style=2 Centered   
    # style=3 Right justified   
       
    if style==1:   
        message = message.ljust(LCD_WIDTH," ")     
    elif style==2:   
        message = message.center(LCD_WIDTH," ")   
    elif style==3:   
        message = message.rjust(LCD_WIDTH," ")   
         
    for i in range(LCD_WIDTH):   
        lcd_byte(ord(message[i]),LCD_CHR)   
       
def lcd_byte(bits, mode):   
    GPIO.output(LCD_RS, mode)    
         
    GPIO.output(LCD_D4, False)   
    GPIO.output(LCD_D5, False)   
    GPIO.output(LCD_D6, False)   
    GPIO.output(LCD_D7, False)   
    if bits&0x10==0x10:   
        GPIO.output(LCD_D4, True)   
    if bits&0x20==0x20:   
        GPIO.output(LCD_D5, True)   
    if bits&0x40==0x40:   
        GPIO.output(LCD_D6, True)   
    if bits&0x80==0x80:   
        GPIO.output(LCD_D7, True)   
         
    time.sleep(E_DELAY)       
    GPIO.output(LCD_E, True)     
    time.sleep(E_PULSE)   
    GPIO.output(LCD_E, False)     
    time.sleep(E_DELAY)         
         
    GPIO.output(LCD_D4, False)   
    GPIO.output(LCD_D5, False)   
    GPIO.output(LCD_D6, False)   
    GPIO.output(LCD_D7, False)   
    if bits&0x01==0x01:   
        GPIO.output(LCD_D4, True)   
    if bits&0x02==0x02:   
        GPIO.output(LCD_D5, True)   
    if bits&0x04==0x04:   
        GPIO.output(LCD_D6, True)   
    if bits&0x08==0x08:   
        GPIO.output(LCD_D7, True)   
         
    time.sleep(E_DELAY)       
    GPIO.output(LCD_E, True)     
    time.sleep(E_PULSE)   
    GPIO.output(LCD_E, False)     
    time.sleep(E_DELAY)   
    
if __name__ == "__main__":  
    main()