to densimitre: can you please teanslate it?

[kate]

hi! ive seen your code about 16f84a working with ADC. can u please translate it in english so i can understand your code because your comments are written in a different language.

 

[densimitre]

hi! ive seen your code about 16f84a working with ADC. can u please translate it in english so i can understand your code because your comments are written in a different language.

Hi again.

This is a reloaded version of ADC0832. Provides Single-Ended and Differential Mode.

adc0832.c

#define AD_CK pin_A2    // Clock
#define AD_DO pin_A3    // Data Out
#define AD_DI pin_A4    // Data In (MUX Channel Selector). Use a PULL-UP resistor
#define AD_CS pin_A7    // Chip Select
 

int adc_result;
int MUX;

void  Clock() {
      output_high(AD_CK);
      output_low(AD_CK);
}

void set_adc(short ch, short mode)  {   //SGL:1/0 ==>Single-Ended/Differential Mode
      int i;
       if(mode==1 & ch==0)    {
       MUX=2;
       }
       if(mode==1 & ch==1)    {
       MUX=3;
       }
       if(mode==0 & ch==0)    {
       MUX=0;
       }
       if(mode==0 & ch==1)    {
       MUX=1;
       }
       output_high(AD_CS);          //CS=1, disable ADC0832
       output_low(AD_CS);           //CS=0, enable ADC0832
       output_high(AD_DI);          //Start BIT
       Clock();

       for (i=0;i<2;i++) {          //Send MUX word
       if((MUX & 0x2)==0)  {        //
         output_low(AD_DI);         //
         }
         else {                     //
         output_high(AD_DI);        //
         }
         MUX<<= 1;
         Clock();

         }
}


void read_adc() {
    int i;
    for (i=0;i<8;i++) {          
         Clock();                
         shift_left(&adc_result, 1, input(AD_DO));
         }
         output_high(AD_CS);     
}

main.c

//use following code to read ADC0832

set_adc(0,1);  //set channel 0, in Single_Ended mode. I can be Differential mode too.
read_adc();

For reading a LM35 output, read this

LM35DZ(2-100ºC) ==>0 volt for 2ºC, 10 mV/ºC....This mean 100-2 steps, 98 steps...and 2ºC of offset. Max output voltage for 100ºC is 98*10mV=0,98 volts

Well, AC0832 does not have a external Vref, because Vref is internally conected to VCC=5 Volts.

5 volts /255 steps=0,02 aprox...it would be like 20mV/ºC...in fact, the output of LM35 muts be multiplied by a factor of 2. Use an LM358 OA. in mode amplifier......

Here we start to read LM35 output on ADC0832...

0,02 => 1ºC
----- ------ ==>D ºC=Xvolt/0,02
Xvolts D ºC


and

255 => 5
----- ----- ==> Xvolt=count/51
count Xvolts


So, DºC=count/51/0,02 = count/1,02. But there is a 2ºC offset, this mean than DºC=count/1,02 + 2.


So, to measure LM35 Temperature with ADC0832 use a code like this

lcd_init();
lcd_gotoxy(1,1);
printf(lcd_putc,"Tempe:");
lcd_gotoxy(12,1);
printf(lcd_putc,"°C");

   while(true) {
   float T;
   set_adc(0,1);                      // Choice CH & Single_Ended mode
   read_adc();
   T=(adc_result/1.02)+2;      //Vref is 5 Volts
   lcd_gotoxy(7,1);
   printf(lcd_putc,"%3.2f",T);
   delay_ms(100);
   }

If you use a different LM35 package, make an suitable modifications in output voltage range calculations

Enjoy

Bye

 

[clandjj]

How I can use the "adcresult" like a binary 8bits? ex:"11111111" Thank you very much...
regards