#include <stdint.h>
#include "tm4c123gh6pm.h"

// Function prototypes
void Timer0A_Init(void);
void ADC0_Init(void);
void ADC0_Start(void);


uint32_t ADC0_Read(void);
void Delay(uint32_t time);

volatile uint32_t pulse_count = 0;
volatile uint32_t pulse_detected = 0;

int main(void)
{
    Timer0A_Init(); // Initialize Timer0A for 1-minute interval
    ADC0_Init();    // Initialize ADC0

    while (1)
    {
        if (pulse_detected)
            {
                pulse_count++;  // Increment pulse count
                pulse_detected = 0;
            }
    }
}



// Timer0A Initialization: Configures Timer0A to generate an interrupt every 1 minute
void Timer0A_Init(void)
    {
        SYSCTL_RCGCTIMER_R |= 0x01;      // Enable clock to Timer0
        TIMER0_CTL_R = 0;                // Disable Timer0A during configuration
        TIMER0_CFG_R = 0;                // Set 32-bit timer configuration
        TIMER0_TAMR_R = 0x02;            // Configure Timer0A in periodic mode
        TIMER0_TAILR_R = 48000000 * 60;  // Load value for 1-minute interval
        TIMER0_IMR_R |= 0x01;            // Enable Timer0A timeout interrupt
        TIMER0_CTL_R |= 0x01;            // Enable Timer0A
        NVIC_EN0_R |= (1 << 19);         // Enable IRQ19 for Timer0A
    }

// ADC0 Initialization: Configures ADC0 for single-channel, single-conversion
void ADC0_Init(void)
    {
        SYSCTL_RCGCADC_R |= 0x01;         // Enable ADC0
        SYSCTL_RCGCGPIO_R |= 0x10;        // Enable clock for Port E
        GPIO_PORTE_AFSEL_R |= 0x08;       // Enable alternate function for PE3
        GPIO_PORTE_DEN_R &= ~0x08;        // Disable digital I/O on PE3
        GPIO_PORTE_AMSEL_R |= 0x08;       // Enable analog function on PE3
        ADC0_ACTSS_R &= ~0x08;            // Disable SS3 during configuration
        ADC0_EMUX_R &= ~0xF000;           // Configure SS3 for software trigger
        ADC0_SSMUX3_R = 0;                // Set channel AIN0 (PE3)
        ADC0_SSCTL3_R = 0x06;             // Set END0 and IE0 bits for single sample
        ADC0_ACTSS_R |= 0x08;             // Enable SS3
    }

// Start ADC0 Conversion
void ADC0_Start(void)
    {
        ADC0_PSSI_R |= 0x08;              // Initiate SS3
    }


// Read ADC0 Value
uint32_t ADC0_Read(void)
    {
        while ((ADC0_RIS_R & 0x08) == 0); // Wait for conversion to complete
        uint32_t result = ADC0_SSFIFO3_R & 0xFFF;  // Read 12-bit ADC result
        ADC0_ISC_R = 0x08;                // Clear completion flag
        return result;
    }

// Timer0A Interrupt Handler: Executes every 1 minute
void Timer0A_Handler(void)
    {
        TIMER0_ICR_R = 0x01; // Clear the timer interrupt flag
        pulse_count = 0;     // Reset pulse count for the next interval
    }

// Sample ADC and check for pulse presence
void check_pulse(void)
    {
        ADC0_Start();
        uint32_t adc_value = ADC0_Read();

        // Convert ADC value to voltage (assuming 3.3V reference)
        float voltage = (adc_value * 3.3) / 4095;

        if (voltage >= 0.4 && voltage <= 0.6)
        {
            pulse_detected = 1; // Signal a valid pulse
        }
    }


// Simple delay function
void Delay(uint32_t time)
    {
        volatile uint32_t count;
        for(count = 0; count < time; count++);
    }