Introduction

In this note I make a program that counts decimal number from 00.0 to 99.99. Eventually, this program will be the base program to both a voltmeter and a thermometer. That's actually the same thing. Calculating the voltage is a tiny bit different.

The program

#include <xc.h>

// CONFIG
#pragma config FOSC = HS        // Oscillator Selection bits (HS oscillator: High-speed crystal/resonator on RA4/OSC2/CLKOUT and RA5/OSC1/CLKIN)
#pragma config WDTE = OFF       // Watchdog Timer Enable bit (WDT disabled and can be enabled by SWDTEN bit of the WDTCON register)
#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)
#pragma config MCLRE = OFF      // MCLR Pin Function Select bit (MCLR pin function is digital input, MCLR internally tied to VDD)
#pragma config CP = OFF         // Code Protection bit (Program memory code protection is disabled)
#pragma config CPD = OFF        // Data Code Protection bit (Data memory code protection is disabled)
#pragma config BOREN = ON      // Brown-out Reset Selection bits (BOR disabled)
#pragma config IESO = ON       // Internal External Switchover bit (Internal External Switchover mode is disabled)
#pragma config FCMEN = ON      // Fail-Safe Clock Monitor Enabled bit (Fail-Safe Clock Monitor is disabled)

#define _XTAL_FREQ 8000000
#define digit1 PORTBbits.RB4
#define digit2 PORTBbits.RB5
#define digit3 PORTBbits.RB6

unsigned char   binary_pattern[]={0b00111111,0b00000110,0b01011011,0b01001111,0b01100110,0b01101101,0b01111101,0b00000111,0b01111111,0b01101111};
unsigned char   binary_pattern_dp[10]= {0b10111111,0b10000110,0b11011011,0b11001111,0b11100110,0b11101101,0b11111101,0b10000111,0b11111111,0b11101111};    // with dp turn on
unsigned int    a1, a2, a3;
unsigned int    counter = 0;

void main(void) {
    CM1CON0 = 0;
    CM2CON0 = 0;

    PORTB = 0b00000000;
    TRISB = 0b00000000;

    PORTC = 0b00000000;
    TRISC = 0b00000000;

    ANSEL = 0;
    ANSELH = 0;

    digit1 = 0; // Decimal
    digit2 = 0; // One's
    digit3 = 0; // Ten's


    while (counter < 9999) {

        a1 = counter / 1000;
        a2 = ((counter/100)%10);
        a3 = ((counter/10)%10);

        counter++;

        // Decimal number
        PORTC = binary_pattern[a3];
        digit1=1;
        __delay_ms(5);
        digit1=0;

        // One's number
        PORTC = binary_pattern_dp[a2];
        digit2 = 1;
        __delay_ms(5);
        digit2 = 0;

        // Ten's number
        PORTC = binary_pattern[a1];
        digit3 = 1;
        __delay_ms(5);
        digit3 = 0;

    }
    return;
}

Work in progress