// Pin setup for analog pins A22 to A29 on Arduino Mega using PORTA
#define LED_PORT PORTA  // Define PORTA as LED output
#define LED_DDR DDRA    // Define Data Direction Register for PORTA

const int photoresistorPin = A0;  // Pin where the photoresistor is connected
const int numLeds = 8;  // Number of LEDs

void setup() {
    // Set all PORTA pins (A22 to A29) as output
    LED_DDR = 0xFF;  // Set all pins of PORTA as output (A22 to A29)

    // Initialize the serial monitor for debugging
    Serial.begin(9600);
}

void loop() {
    // Read the value from the photoresistor (range 0 to 1023)
    int lightLevel = analogRead(photoresistorPin);

    // Print the light level for debugging purposes
    Serial.print("Light Level: ");
    Serial.println(lightLevel);

    // Map the light level (0-1023) to the number of LEDs (0-8)
    int ledsToLight = map(lightLevel, 0, 1023, 0, numLeds);

    // Light up the LEDs based on the light level from A22 to A29
    // We manipulate the bits in PORTA to turn on or off the LEDs
    if (ledsToLight > 0) {
        LED_PORT = (1 << (ledsToLight)) - 1;  // Turn on LEDs from A22 to A29 based on light level
    } else {
        LED_PORT = 0x00;  // Turn off all LEDs
    }

    // Add a small delay before reading again
    delay(100);
}