ADC generation using PIC16f72 microcontroller.

[djc]

Hi,
Here is the code for ADC using 16f72.

/****************************************************************
1) RA3 is selected as input channel
2) Knob is connected to RA3 pin on kit, by varying it we can have ADC result which is displayed on PORTB.
3) GO/DONE bit must be set before monitoring it for going low.
******************************************************************/




void main() {
     unsigned int temp,i;
     //TRISA = 0xff;      //Set port A direction as i/p
     TRISA = 0x00;        //Port A as output
     PORTA = 0X00;        //ALL BITS OFF
     ADCON0 = 0X18;       //CLOCK SELECTION AND ANALOG CHANNEL SELECTION channel RA3 as input
     TRISB = 0x00;        //Set port B as output
     TRISC = 0x00;
     ADCON1 = 0X01;       //ALL CHANNELS AS ANALOG INPUT Vref is RA3
     //ADCON1 = 0x00;     //Vref is VDD
     TRISA3_bit = 0;      //Port A 0th bit as input
     TRISA2_bit = 0;
     TRISA1_bit = 1;
     TRISA0_bit = 1;

                PORTB = 0xFF;
                Delay_ms(1000);
                PORTB = 0x00;
                Delay_ms(1000);
                PORTC = 0x00;
                               while(1)

                               {
                                       ADRES = 0x00;
                                       ADCON0.ADON = 0x01;                 //Turn on the ADC
                                       ADCON0.GO = 1;
                                       //ADCON0 = ADCON0 & 0x04;
                                       //while((ADCON0 & 0x04)==1);    // Wait till conversion is going on
                                       while (ADCON0 == 0x04);
                                       //while(ADCON0.GO == 1);
                                       ADCON0 = 0x00;          // Stop the ADC
                                       // ADIF = 0;
                                       //temp = ADRES;
                                       PORTB = ADRES;
                                       //PORTA = ADRES;
                                       //PORTC = ADRES;
                                       Delay_us(2);    //Call delay 2 microseconds;
                               }

}

 

[AbdulMoeez]

If you study datasheet of pic16F72, they mentioned that only following adc configuration you can use. use cannot make only AN3 for adc use have to use following group configuration.

1- NO_ANALOGS 7 // None
2- ALL_ANALOG 0 // A0 A1 A2 A3 A5
3- AN0_AN1_AN2_AN4_VSS_VREF 1 // A0 A1 A2 A5 VRefh=A3
4- AN0_AN1_AN3 4 // A0 A1 A3
5- AN0_AN1_VSS_VREF 5 // A0 A1 VRefh=A3

- - - Updated - - -

ccs compiler code // tested code
***************************************************************************************
1) RA3 is selected as input channel
2) Knob is connected to RA3 pin on kit, by varying it we can have ADC result which is displayed on PORTB.
***************************************************************************************

#include <pic16f72.h>

#device adc=8

#FUSES NOWDT,NOBROWNOUT,NOLVP,HS,PUT

#use delay(clock=20000000)

unsigned int8 adc_value;

void main(){

set_tris_b(0x00);
set_tris_a(0xff);

setup_adc(ADC_CLOCK_INTERNAL);
setup_adc_ports(AN0_AN1_AN3);
set_adc_channel(3);
delay_ms(10);
while(1){
adc_value = read_adc();
output_b(adc_value);
delay_ms(2);
}

}

 

[djc]

Hi,

Thanx for the suggestions sir. The program has been modified for other application using ADC. Though we have to use group of channels as input but we will get input for ADC on certain specific channel right? Correct me if I am wrong.

Thanking You

- - - Updated - - -

Hi,

Thanx for the suggestions sir. The program has been modified for other application using ADC. Though we have to use group of channels as input but we will get input for ADC on certain specific channel right? Correct me if I am wrong.

Thanking You

 

[AbdulMoeez]

yes, you are correct..... Though we have to use group of channels as input but we will get input for ADC on certain specific channel.....