#include <LPC17xx.h>

#define RS_CTRL 0x08000000
#define EN_CTRL 0x10000000
#define DT_CTRL 0x07800000

unsigned long int temp1 = 0, temp2 = 0, i, j;
unsigned char flag1 = 0, flag2 = 0;
unsigned long result, y; // ADC variables
unsigned char adc_string[10]; // Buffer for ADC result string

void lcd_write(void);
void port_write(void);
void delay_lcd(unsigned long);
void int_to_string(unsigned long num, unsigned char* str);

unsigned long int init_command[] = {0x30, 0x30, 0x30, 0x20, 0x28, 0x0C, 0x01, 0x80};

int main() {
    // LCD GPIO setup
    LPC_GPIO0->FIODIR = DT_CTRL | RS_CTRL | EN_CTRL;

    // ADC setup
    LPC_PINCON->PINSEL3 = 3 << 28; // P1.30 function 3
    LPC_SC->PCONP = 1 << 12; // power control
    LPC_ADC->ADCR = 1 << 4 | 1 << 16 | 1 << 21; // ADC4, burst mode, enable
    LPC_ADC->ADINTEN = (1 << 4); // Interrupt enable
    NVIC_EnableIRQ(ADC_IRQn);

    // LCD initialization
    flag1 = 0;
    for (i = 0; i < 8; i++) {
        temp1 = init_command[i];
        lcd_write();
    }

    flag1 = 1;

    while(1) {
        // Convert ADC result to string and display
        int_to_string(result, adc_string);

        // Clear display and reset cursor
        flag1 = 0;
        temp1 = 0x01; // Clear display
        lcd_write();
        temp1 = 0x80; // Set cursor to home
        lcd_write();
        flag1 = 1;

        // Display the ADC result
        i = 0;
        while(adc_string[i] != '\0') {
            temp1 = adc_string[i];
            i++;
            lcd_write();
        }

        delay_lcd(5000000); // Update every ~1 second
    }
}

void ADC_IRQHandler(void) {
    result = (LPC_ADC->ADGDR & (0xFFF << 4)) >> 4; // Read 12-bit ADC result
    y = (LPC_ADC->ADDR4 & (0xFFF << 4)) >> 4; // Done bit reset
}

void int_to_string(unsigned long num, unsigned char* str) {
    int i = 0, j;
    unsigned char temp;

    // Handle zero case
    if (num == 0) {
        str[0] = '0';
        str[1] = '\0';
        return;
    }

    // Convert number to string (reverse order)
    while (num > 0) {
        str[i++] = (num % 10) + '0';
        num /= 10;
    }
    str[i] = '\0';

    // Reverse the string
    for (j = 0; j < i/2; j++) {
        temp = str[j];
        str[j] = str[i-1-j];
        str[i-1-j] = temp;
    }
}

void lcd_write(void) {
    flag2 = (flag1 == 1) ? 0 : (((temp1 == 0x30) || (temp1 == 0x20)) ? 1 : 0);

    temp2 = temp1 & 0xf0;
    temp2 = temp2 << 19;
    port_write();

    if (!flag2) {
        temp2 = temp1 & 0x0f;
        temp2 = temp2 << 23;
        port_write();
    }
}

void port_write(void) {
    LPC_GPIO0->FIOPIN = temp2;

    if (flag1 == 0) {
        LPC_GPIO0->FIOCLR = RS_CTRL;
    } else {
        LPC_GPIO0->FIOSET = RS_CTRL;
    }

    LPC_GPIO0->FIOSET = EN_CTRL;
    delay_lcd(100);
    LPC_GPIO0->FIOCLR = EN_CTRL;
    delay_lcd(500000);
}

void delay_lcd(unsigned long r1) {
    unsigned long r;
    for (r = 0; r < r1; r++);
    return;
}