ADC_Testing/main.c

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

#define RED_LED (1 << 1)  // PF1 for the red LED
#define ADC_30MV_THRESHOLD (30 * 4096 / 3300)  // 30mV to ADC value
#define ADC_10MV_THRESHOLD (10 * 4096 / 3300)  // 10mV to ADC value

void PortF_Init(void);
void ADC0_Init(void);
uint16_t ADC0_Read(void);

int main(void) {
    int adc_value;
    int high_state = 0;  // 0: Below 10mV, 1: Above 30mV

    PortF_Init();  // Initialize LED
    ADC0_Init();   // Initialize ADC

    // Ensure LED is off by default
    GPIO_PORTF_DATA_R &= ~RED_LED;

    while (1) {
        adc_value = ADC0_Read();  // Read ADC value

        if (adc_value >= ADC_30MV_THRESHOLD && high_state == 0) {
            GPIO_PORTF_DATA_R |= RED_LED;  // Turn on red LED
            high_state = 1;               // Signal is above 30mV
        } else if (adc_value < ADC_10MV_THRESHOLD && high_state == 1) {
            GPIO_PORTF_DATA_R &= ~RED_LED;  // Turn off red LED
            high_state = 0;                 // Reset to allow new detection
        } else if (adc_value < ADC_10MV_THRESHOLD) {
            GPIO_PORTF_DATA_R &= ~RED_LED;  // Ensure LED is off when no signal
        }
    }
}

void PortF_Init(void) {
    SYSCTL_RCGCGPIO_R |= (1U << 5);  // Enable clock for Port F // SYSCTL_RCGC2_R |= 0x00000020;
    // while ((SYSCTL_PRGPIO_R & (1U << 5)) == 0);  // Wait for Port F to be ready

    GPIO_PORTF_DIR_R |= 0x01;    // Set PF1 as output
    GPIO_PORTF_DEN_R |= 0x01;    // Enable digital function for PF1

    GPIO_PORTF_DATA_R &= ~0x01;  // Ensure LED is off initially
}

void ADC0_Init(void) {
    SYSCTL_RCGCADC_R |= 0x01;  // Enable ADC0 clock
    SYSCTL_RCGCGPIO_R |= 0x10;  // Enable clock for Port E
    // while ((SYSCTL_PRGPIO_R & (1U << 4)) == 0);  // Wait for Port E to be ready

    GPIO_PORTE_AFSEL_R |= 0x08;  // Enable alternate function on PE3
    GPIO_PORTE_DEN_R &= ~(1U << 3);  // Disable digital I/O on PE3 // GPIO_PORTE_DEN_R &= ~(0x08);
    GPIO_PORTE_AMSEL_R |= 0x08;  // Enable analog function on PE3

    ADC0_ACTSS_R &= ~8;              // Disable sample sequencer 3
    ADC0_EMUX_R = (ADC0_EMUX_R & 0xFFFF0FFF);  // Software trigger for SS3
    ADC0_SSMUX3_R = 0;               // Set channel AIN0 (PE3)
    ADC0_SSCTL3_R = 6;               // End of sequence and enable interrupt
    ADC0_ACTSS_R |= 8;               // Enable sample sequencer 3
}

uint16_t ADC0_Read(void)
    {
    ADC0_PSSI_R = 8;                 // Start sampling on SS3
    while ((ADC0_RIS_R & 8) == 0);   // Wait for conversion to complete
    uint16_t result = ADC0_SSFIFO3_R & 0xFFF;  // Read 12-bit ADC value
    ADC0_ISC_R = 8;                  // Clear the completion flag
    return result;
    }