#define FOSC 1843200 // Clock Speed
#define BAUD 9600
#define MYUBRR FOSC/16/BAUD-1
volatile uint16_t adcResult = 0;  // Variable to hold the ADC result

void setup() {
  Serial.begin(9600);           // Initialize Serial communication
  init_adc();                   // Initialize the ADC
  sei();                        // Enable global interrupts
}

void loop() {
  // The ADC value will be updated when the interrupt occurs
  Serial.print("ADC Value: ");
  Serial.println(adcResult);     // Print the ADC result
  delay(500);                   // Add a delay for readability
}

void init_adc() {
  ADMUX = 0x40;                 // Reference: AVCC, Input Channel: ADC0
  ADCSRA = 0x87;                // Enable ADC, Prescaler: 128
  ADCSRA |= (1 << ADIE);        // Enable ADC interrupt
  ADCSRA |= (1 << ADEN);        // Enable the ADC
  ADCSRA |= (1 << ADSC);        // Start the first conversion
}

ISR(ADC_vect) {
  uint8_t lowByte = ADCL;  // Read the low byte of ADC result
  uint8_t highByte = ADCH; // Read the high byte of ADC result
  
  adcResult = ((uint16_t)highByte << 8) | lowByte;  // Combine the high and low bytes to form a 10-bit result
  
  ADCSRA |= (1 << ADSC);  // Start the next conversion
}
// USART Initialization
void USART_Init(unsigned int ubrr) {
  /* Set baud rate */
  UBRR0H = (unsigned char)(ubrr >> 8);
  UBRR0L = (unsigned char)ubrr;
  UCSR0B = (1 << RXEN0) | (1 << TXEN0); /* Enable receiver and transmitter */
  UCSR0C = (1 << UCSZ01) | (1 << UCSZ00); /* Set frame format: 8 data bits, 1 stop bit */
}
// The USART Transmitter
void USART_Transmit(unsigned char data) {
  while (!(UCSR0A & (1 << UDRE0)));     /* Wait for empty transmit buffer */
  UDR0 = data;                          /* Put data into buffer, sends the data */
}
//USART_Transmit
void USART_Transmit(unsigned int data) {
  while (!(UCSR0A & (1 << UDRE0))); /* Wait for empty transmit buffer */
  UCSR0B &= ~(1 << TXB80);  /* Copy 9th bit to TXB8 */
  if (data & 0x0100)
    UCSR0B |= (1 << TXB80);
  UDR0 = data;/* Put data into buffer, sends the data */
}