Week 11 Assignment | Serial Communication Exercise 1-3

Example 1 – Arduino to p5 communication

IMG_3382

P5 code

let X = 0; // ellipse x position


function setup() {
  createCanvas(400, 400); 
}

function draw() {
  background(240); 

  fill('rgb(134,126,126)'); 
  ellipse(X, height/2, 80); 
}

function keyPressed() {
  if (key === " ") {
    setUpSerial(); // Start the serial connection on space bar press
  }
}

// Processes incoming data from Arduino
function readSerial(data) {
  if (data != null) {
    let fromArduino = split(trim(data), ","); // Split incoming data by commas

    if (fromArduino.length >= 1) {
      // Process the first value for X position
      let potValue = int(fromArduino[0]); // Convert string to integer
      X = map(potValue, 0, 1023, 50, width - 50); // Map potentiometer value to X position
      Y = height / 2; // Keep Y position constant
    }
  }
}

Arduino code

void setup() {
  Serial.begin(9600); //  serial communication
}

void loop() {
  int potValue = analogRead(A0); // potentiometer value
  Serial.println(potValue);     // send the value to the serial port
  delay(10);                   
}

Example 2 – P5 to Arduino Communication

p5 code

let brightness = 0; // Brightness value to send to Arduino

function setup() {
  createCanvas(640, 480);
  textSize(18);
}

function draw() {
  background(255);

  if (!serialActive) {
    // If serial is not active display instruction
    text("Press Space Bar to select Serial Port", 20, 30);
  } else {
    // If serial is active, display connection status and brightness value
    text("Connected", 20, 30);
    text('Brightness = ' + str(brightness), 20, 50);
  }

  // Map the mouseX position (0 to width) to brightness (0 to 255)
  brightness = map(mouseX, 0, width, 0, 255);
  brightness = constrain(brightness, 0, 255); // Ensures brightness is within the range 0-255

  // Sends brightness value to Arduino
  sendToArduino(brightness);
}

function keyPressed() {
  if (key == " ") {
    // Start serial connection when the space bar is pressed
    setUpSerial();
  }
}


function readSerial(data) {
  if (data != null) {

  }
}
// We dont need this part of the code because we are not getting any value from the Arduino

// Send brightness value to Arduino
function sendToArduino(value) {
  if (serialActive) {
    let sendToArduino = int(value) + "\n"; // Convert brightness to an integer, add newline
    writeSerial(sendToArduino); // Send the value using the serial library
  }
}

Arduino code

void setup() {
  Serial.begin(9600); //  serial communication
}

void loop() {
  int potValue = analogRead(A0); // potentiometer value
  Serial.println(potValue);     // send the value to the serial port
  delay(10);                   
}

Example 3 – Bi-Directional Communication

p5 code

let velocity;
let gravity;
let position;
let acceleration;
let wind;
let drag = 0.99;
let mass = 50;


let windValue = 0; // Wind value from Arduino (light sensor)
let serialConnected = false; // Tracks if the serial port is selected

function setup() {
  createCanvas(640, 360);
  textSize(18); 
  noFill();

  position = createVector(width / 2, 0);
  velocity = createVector(0, 0);
  acceleration = createVector(0, 0);
  gravity = createVector(0, 0.5 * mass);
  wind = createVector(0, 0);
}

function draw() {
  background(255);

  if (!serialConnected) {
    // Show instructions to connect serial port
    textAlign(CENTER, CENTER);
    fill(0); // Black text
    text("Press Space Bar to select Serial Port", width / 2, height / 2);
    return; // Stop loop until the serial port is selected
  } else if (!serialActive) {
    // Show connection status while waiting for serial to activate
    textAlign(CENTER, CENTER);
    fill(0);
    text("Connecting to Serial Port...", width / 2, height / 2);
    return; // Stop until the serial connection is active
  } else {
    // display wind value and start the simulation if connected
    textAlign(LEFT, TOP);
    fill(0);
    text("Connected", 20, 30);
    text('Wind Value: ' + windValue, 20, 50);
  }

  // Apply forces to the ball
  applyForce(wind);
  applyForce(gravity);

  // Update motion
  velocity.add(acceleration);
  velocity.mult(drag);
  position.add(velocity);
  acceleration.mult(0);

  // Draw the ball
  ellipse(position.x, position.y, mass, mass);

  // Check for bounce
  if (position.y > height - mass / 2) {
    velocity.y *= -0.9; 
    position.y = height - mass / 2; // Keep the ball on top of the floor 

    // Sends signal to Arduino about the bounce
    sendBounceSignal();
  }

  // Update wind force based on Arduino input
  wind.x = map(windValue, 0, 1023, -1, 1); // Map sensor value to wind range
}

function applyForce(force) {
  let f = p5.Vector.div(force, mass);// Force divided by mass gives acceleration
  acceleration.add(f);
}

// Send a bounce signal to Arduino
function sendBounceSignal() {
  if (serialActive) {
    let sendToArduino = "1\n"; // Signal Arduino with "1" for a bounce
    writeSerial(sendToArduino);
  }
}

// incoming serial data from Arduino
function readSerial(data) {
  if (data != null) {
    windValue = int(trim(data)); // store the wind value
  }
}

// Press space bar to initialize serial connection
function keyPressed() {
  if (key == " ") {
    setUpSerial(); // Initialize the serial connection
    serialConnected = true; // Mark the serial port as selected
  }
}

// Callback when serial port is successfully opened
function serialOpened() {
  serialActive = true; // Mark the connection as active
}

Arduino code

const int ledPin = 9;  // Digital pin 9 connected to the LED
const int lightSensor = A0; // Analog input pin A0 for the light sensor

void setup() {
  Serial.begin(9600);      // Start serial communication
  pinMode(ledPin, OUTPUT); // Set LED pin as an output
}

void loop() {
  // Read the light sensor value
  int lightValue = analogRead(lightSensor);

  // Send the light value to p5.js
  Serial.println(lightValue);

  // Check for bounce signal (when ball touches the ground) from p5.js
  if (Serial.available() > 0) {
    int bounceSignal = Serial.parseInt();
    if (Serial.read() == '\n' && bounceSignal == 1) {
      // Turn on the LED briefly to indicate a bounce
      digitalWrite(ledPin, HIGH);
      delay(100);
      digitalWrite(ledPin, LOW);
    }
  }

  delay(50); // Small delay 
}