​

function setup() {

  createCanvas(640, 480);

  textSize(18);

​

  // Check if serial is active and set it up if not

  if (!serialActive) {

    setUpSerial(); // Initialize serial communication

  }

}

​

function draw() {

  background(30); // Dark background

  fill(255); // White text

  text("Use the UP and DOWN arrows to control LED brightness", 20, 30);

​

  // Display the current brightness value

  text("Brightness: " + brightness, 20, 60);

}

​

function keyPressed() {

  if (keyCode === UP_ARROW) {

    // Increase brightness

    brightness = min(brightness + 10, 255); // Max brightness is 255

    sendBrightness();

  } else if (keyCode === DOWN_ARROW) {

    // Decrease brightness

    brightness = max(brightness - 10, 0); // Min brightness is 0

    sendBrightness();

  } else if (key === " ") {

    // Start serial connection when spacebar is pressed

    setUpSerial();

  }

}

​

function sendBrightness() {

  if (writer) {

    // Send the brightness value to Arduino

    writer.write(brightness + "\n");

  } else {

    console.error("Writer is not available. Please connect to the serial port.");

  }

}

// ARDUINO CODE

// int ledPin = 9; // LED connected to PWM pin 9

// int brightness = 0; // Variable to store brightness value from p5.js

​

// void setup() {

//   Serial.begin(9600); // Start serial communication

//   pinMode(ledPin, OUTPUT); // Set LED pin as an output

// }

​

// void loop() {

//   // Check if data is available to read

//   if (Serial.available() > 0) {

//     // Read the brightness value sent from p5.js

//     brightness = Serial.parseInt();

​

//     // Constrain the brightness value to 0-255

//     brightness = constrain(brightness, 0, 255);

​

//     // Set the LED brightness

//     analogWrite(ledPin, brightness);

//   }

// }

​