12F675 and LM35 coding issue

[Acetronics2]

Hi, Bobbo

Your main problem was scaling temps before displaying ...

try this one :

'****************************************************************
 '*  Author  : [select VIEW...EDITOR OPTIONS]                    *
'*  Notice  : Copyright (c) 2010 [select VIEW...EDITOR OPTIONS] *
'*          : All Rights Reserved                               *
'*  Date    : 05/03/2010                                        *
'*  Version : 1.0                                               *
'*  Notes   :                                                   *
'*          :                                                   *
'****************************************************************
'*  Name    : Temp 675'Using PIC 12F675 with White LED connected to Pin 7, Blue LED on Pin 6, 
'Red LED on pin 7. Vdd is supplied as a regulated 5v to pin 1, Ground to pin 8.
'LM 35 connected to Vdd and Ground + Centre pin connected to Pin 3 (AN3)
'Pin 4 disconnected - Have tried connecting to Vdd with 10K res and turning MCLR_on with no sucess 
                                               
@ device pic12F675,INTRC_OSC,wdt_on,pwrt_on,protect_off,MCLR_off

'DEFINE CHAR_PACING 1000
DEFINE OSC 4                                      'Set internal osc. To 4MHz

'---------Define ADCin Parameters   
DEFINE ADC_BITS 10 'set number of bits in result
DEFINE ADC_CLOCK 3 'set clock source (3=rc)
DEFINE ADC_SAMPLEUS 50 'Set sampling time in uS

ANSEL  = %00111000 ' Set ADC clock = Frc, GPIO.4, 1 = A/D 
ADCON0 = %10001100 ' Right justify, use Vdd as Vref          ' Select channel 3 !!! 
                   
CMCON = 7


'---------Define Vairables         
samples VAR WORD        ' Multiple A/D sample accumulator
dummy   var word        ' DIV32 intermediate value
sample  VAR BYTE        ' Holds number of samples to take
temp    VAR BYTE        ' Temperature storage  ... might be a WORD !!! ( 0 - 1023 !!! )

CLEAR           ' clear Variables

LED0	Con	0	' GPIO.0 = White LED
LED1    CON 1   ' GPIO.1 = Blue LED              
LED2    CON 2   ' GPIO.2 = Red LED   
               
'--------Configuring I/O PORTS
GPIO = 0
TRISIO = %010000   'set GPIO.0, GPIO.1, GPIO.2 as output (LEDs) & GPIO.4 as input

'---------Main Program 
'Flash White LED on Start

HIGH LED0
Pause 500
LOW LED0       
              
While 1

 TEMP_READ:                                      'Subroutine to measure temp   input = 10 mv/°C ~250 mv 

            temp = 0                            'Clear temp register
            samples = 0                         'Clear samples register
             
            FOR sample = 1 TO 20                'Take 20 samples
                ADCIN 3, temp                   ' Read AN3 into temp variable    result is ~ 50  ( .25 / 5 * 1024 )
                samples = samples + temp      
                PAUSE 12                       ' Wait 1/4 seconds per display ... (20 x 12 ms )
            NEXT sample
                                     
                temp = samples/20               'Average over 20 samples (Every 5 seconds)   result is ~ 50
'                temp=(temp* 10)/2               ' Result is 250 ... may overflow !!! so, the mult is no use !!!

'*******************************************************************************
' Trim to scale
'********************************************************************************

  Dummy = 500 * temp                            ' 500 = 5000 mv full scale  / 10 mv per degree
  temp = DIV32 1024                               ' Number is Deg C Now ...

'********************************************************************************

 SELECT CASE temp

    CASE is < 20    'Less than 20deg - White LED                                             
  
    HIGH LED0
    LOW LED1
    LOW LED2
 

    CASE is < 31        'Between 20deg and 30deg - Blue
    
    LOW LED0
    HIGH LED1
    LOW LED2
  

    CASE is < 45         'Greater than 30deg - but less than 45 deg Red
    
    HIGH LED2
    LOW LED1
    LOW LED0
    
    CASE Else              ' Too cold !!! or dangerously hot ... let's blink everyting !!!
    
    HIGH LED0
    HIGH LED1
    HIGH LED2
    
    PAUSE 250
    
    LOW LED0
    LOW LED1
    LOW LED2
    
 END SELECT
 
wend

END

Interesting parts have been explained ...

now, have a good bath ... you've sweat a lot on this one ... ROFL.