PIC16F690 - LCD counter - The software

20.05.24

Embedded

New updated version of the Engine Timer

This is a work in progress, and the code is not finished. It need some comments

The code has been slightly change. Now we're counting minutes in total and not divinding them into days:hours:minutes.

#include < xc.h >

// CONFIGURATION BITS
#pragma config FOSC = INTRCIO        // 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 = ON       // MCLR Pin Function Select bit (MCLR pin function is MCLR)
#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 = OFF       // Brown-out Reset Selection bits (BOR enabled)
#pragma config IESO = OFF        // Internal External Switchover bit (Internal External Switchover mode is enabled)
#pragma config FCMEN = OFF       // Fail-Safe Clock Monitor Enabled bit (Fail-Safe Clock Monitor is enabled)

#define _XTAL_FREQ 8000000      // Compiler frequency
#define Counter_LED RC4         // Led toggles every second
#define LED RC5                 // Power on LED
#define LCD_RS RA2              // RS PIN for LCD
#define LCD_EN RA1              // Enable PIN for LCD
#define LCD_DATA PORTC          // LCD Port

volatile char counter, buffer[3]; // This variables has to be volatile to be changed in the interrup routine

// Function to configure Oscillation
void osc_init(void) {
    OSCCONbits.IRCF = 0b111;    // 8MHz
    OSCCONbits.OSTS = 1;        // Running from Fosc in config/External clock
    OSCCONbits.HTS = 1;         // Stable
    OSCCONbits.SCS = 0;         // Clock source defined by Fosc
    return;
}

// Function to strobe the LCD, "ping" the En-pin
int lcd_strobe(void) {
    LCD_EN = 1;
    __delay_us(1);
    LCD_EN = 0;
}

// Function to write on the LCD
void lcd_write(unsigned char c) {
    __delay_ms(1);
    LCD_DATA = ((c >>4) & 0x0f);
    lcd_strobe();
    LCD_DATA = (c & 0x0f);
    lcd_strobe();
}

// Function to reset/ clear the LCD
void lcd_clear(void) {
 LCD_RS = 0;
 lcd_write(0x1);
 __delay_ms(1);
}

// Function to write a string to the LCD
void lcd_puts(const char *s) {
    LCD_RS = 1;
    while(*s)
        lcd_write(*s++);
}

// Function to place the cursor on the LCD
void lcd_goto(unsigned char pos) {
    LCD_RS = 0;
    lcd_write(0x80+pos);
}

// Function to initialize the LCD
void lcd_init(void) {
    char init_value;
    init_value = 0x3;
    
    LCD_RS = 0;
    LCD_EN = 0;
    
    __delay_ms(15);
    
    LCD_DATA = init_value;
    lcd_strobe();   __delay_ms(10);
    lcd_strobe();   __delay_ms(10);
    LCD_DATA = 2;
    lcd_strobe();
    lcd_write(0x0e);    // Display on, cursor on, blink off
}

void short_welcome(void) {
    lcd_clear();
    lcd_goto(0);
    lcd_puts("  HOUR COUNTER");
    lcd_goto(0x29);
    lcd_puts("    VER 0.1");
    __delay_ms(3000);
    lcd_clear();
}

// Function to initialize the timer
void timer_init() {
    TMR1H = TMR1L = 0; // Clear TMR1H & TMR1L
    T1CONbits.T1CKPS1 = 0; // Prescaler 1:1
    T1CONbits.T1CKPS0 = 0; // Prescaler 1:1
    PIE1bits.TMR1IE = 1; // TMR1 overflow interrup enable bit
    T1CONbits.TMR1ON = 1; // Timer 1 on
    INTCONbits.PEIE = 1; // Enable perepheral interrupt
    INTCONbits.GIE = 1; // Enable global interrupt   
}

// Function to handle timer1 interrupts
// Counter = Fosc/instruction cycle * prescaler * timer1 resolution
// Counter = 8Mhz / (4 instructions pr cycle * 1 prescaler value * 2^16 resolution)
// Counter = 8000000 / (4 * 1 * (2^16))
// Counter = 30.51
void __interrupt() ISR() {
    if (PIR1bits.TMR1IF == 1) { // Timer1 overflow interrupt flag
        counter++;
        if (counter == 30) { // Check if TMR1 has overflown
            Counter_LED ^= 1; // Toggle LED
            // update_time();
            // show_time();
            // show_total_time();
            counter = 0;
        }
        PIR1bits.TMR1IF = 0; // Clear the overflow flag
    }
}

void main(void) {
    TRISA = 0b00000000; // TRISA output
    TRISB = 0b0000;     // TRISB output
    TRISC = 0b00000000; // TRISC output
    PORTA = 0b00000000; // PORTA low
    PORTB = 0b0000;     // PORTB low
    PORTC = 0b00000000; // PORTC low
    ANSEL = 0;          // Disable input buffer on ANSEL
    ANSELH = 0;         // Disable input buffer on ANSELH
    CM1CON0 = 0;        // Comparator C1 control register 0, disabled
    CM2CON0 = 0;        // Comparator C2 control register 0, disabled
    
    osc_init(); // Initialize the oscillator
    lcd_init(); // Initialize the LCD
    lcd_clear();    // Clear the LCD
    short_welcome();    // Display welcome message
    LED = 1;    // Turn LED on => Power LED

    timer_init();   // Initialize the timer
    
    while (1) {
        // Nothing to do here...
    }
}

You'll find the circuit here: Link

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