#include <xc.h>
#include <stdio.h>
 
// ================= CONFIG =================
// Use these settings in MPLAB/XC8
#pragma config FOSC = HS        // HS oscillator
#pragma config WDTE = OFF       // Watchdog Timer disabled
#pragma config PWRTE = ON       // Power-up Timer enabled
#pragma config BOREN = ON       // Brown-out Reset enabled
#pragma config LVP = OFF        // Low-Voltage Programming disabled
#pragma config CPD = OFF        // Data EEPROM Memory Code Protection off
#pragma config WRT = OFF        // Flash Program Memory Write Protection off
#pragma config CP = OFF         // Flash Program Memory Code Protection off
 
#define _XTAL_FREQ 20000000     // 20 MHz Crystal (change if different)
 
// ================= LCD CONNECTIONS =================
// LCD on PORTD
#define RS RD0
#define EN RD1
#define D4 RD2
#define D5 RD3
#define D6 RD4
#define D7 RD5
 
// ================= FUNCTION PROTOTYPES =================
void Lcd_Command(char);
void Lcd_Char(char);
void Lcd_Init(void);
void Lcd_String(const char *);
void Lcd_Clear(void);
void Lcd_Set_Cursor(char, char);
unsigned int Read_ADC(unsigned char channel);
 
// ================= GLOBAL VARIABLES =================
volatile unsigned int pulse_count = 0;
unsigned int heart_rate = 0;
 
// ================= MAIN PROGRAM =================
void main(void) {
    unsigned int adc_value;
    float temperature;
    char buffer[16];
 
    // ADC setup
    ADCON1 = 0x80;      // Right justified, Vref=VDD
    ADCON0 = 0x41;      // ADC enabled, Channel 0 (AN0)
 
    // LCD setup
    TRISD = 0x00;       // LCD port output
    Lcd_Init();
 
    // RB0 as heart pulse input (external interrupt)
    TRISB0 = 1;         // RB0 input
    INTEDG = 1;         // Interrupt on rising edge
    INTE = 1;           // Enable RB0 external interrupt
    GIE = 1;            // Enable global interrupts
 
    // Timer1 for 1-second period
    T1CON = 0x31;       // Prescaler 8, Timer1 ON
    TMR1H = 0;
    TMR1L = 0;
 
    while(1) {
        // ====== Read Temperature from LM35 ======
        adc_value = Read_ADC(0);                    // Read AN0
        temperature = (adc_value * 4.88) / 10.0;    // LM35 = 10mV/°C
 
        // ====== Heart Rate Calculation every ~1s ======
        if (TMR1H > 0x3C) {   // Adjust for ~1 second
            heart_rate = pulse_count * 60; // convert to bpm
            pulse_count = 0;
            TMR1H = 0;
            TMR1L = 0;
        }
 
        // ====== Display on LCD ======
        Lcd_Clear();
 
        sprintf(buffer, "Temp: %.1f C", temperature);
        Lcd_Set_Cursor(1, 1);
        Lcd_String(buffer);
 
        sprintf(buffer, "HR: %u bpm", heart_rate);
        Lcd_Set_Cursor(2, 1);
        Lcd_String(buffer);
 
        __delay_ms(500);
    }
}
 
// ================= ADC FUNCTION =================
unsigned int Read_ADC(unsigned char channel) {
    if(channel > 7) return 0;   // PIC16F877A has 8 ADC channels (AN0–AN7)
 
    ADCON0 = (channel << 3) | 0x41;  // Select channel, turn on ADC
    __delay_ms(2);                   // Acquisition time
    GO_DONE = 1;                     // Start conversion
    while(GO_DONE);                  // Wait until done
    return ((ADRESH << 8) + ADRESL); // Return result
}
 
// ================= LCD FUNCTIONS =================
void Lcd_Command(char cmd) {
    RS = 0;
    D4 = (cmd >> 4) & 1;
    D5 = (cmd >> 5) & 1;
    D6 = (cmd >> 6) & 1;
    D7 = (cmd >> 7) & 1;
    EN = 1; __delay_ms(1); EN = 0;
 
    D4 = cmd & 1;
    D5 = (cmd >> 1) & 1;
    D6 = (cmd >> 2) & 1;
    D7 = (cmd >> 3) & 1;
    EN = 1; __delay_ms(1); EN = 0;
 
    __delay_ms(2);
}
 
void Lcd_Char(char data) {
    RS = 1;
    D4 = (data >> 4) & 1;
    D5 = (data >> 5) & 1;
    D6 = (data >> 6) & 1;
    D7 = (data >> 7) & 1;
    EN = 1; __delay_ms(1); EN = 0;
 
    D4 = data & 1;
    D5 = (data >> 1) & 1;
    D6 = (data >> 2) & 1;
    D7 = (data >> 3) & 1;
    EN = 1; __delay_ms(1); EN = 0;
 
    __delay_ms(2);
}
 
void Lcd_Init() {
    Lcd_Command(0x02);   // Initialize
    Lcd_Command(0x28);   // 4-bit mode, 2-line, 5x7
    Lcd_Command(0x0C);   // Display ON, Cursor OFF
    Lcd_Command(0x06);   // Auto-increment
    Lcd_Command(0x01);   // Clear display
}
 
void Lcd_String(const char *str) {
    while(*str) Lcd_Char(*str++);
}
 
void Lcd_Clear() {
    Lcd_Command(0x01);
}
 
void Lcd_Set_Cursor(char row, char col) {
    char pos;
    if(row == 1) pos = 0x80 + (col - 1);
    else pos = 0xC0 + (col - 1);
    Lcd_Command(pos);
}
 
// ================= INTERRUPT SERVICE ROUTINE =================
void __interrupt() ISR(void) {
    if (INTF) {   // RB0 interrupt flag
        pulse_count++;
        INTF = 0; // Clear interrupt flag
    }
}
 

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