Month: November 2025

For this week’s assignment, Zeina and I worked on three different exercises that focused on serial communication.

1- Make something that uses only one sensor  on Arduino and makes the ellipse in p5 move on the horizontal axis, in the middle of the screen, and nothing on arduino is controlled by p5

ARDUINO CODE

void setup() {
  Serial.begin(9600);
}

void loop() {
  int sensorValue = analogRead(A1); // 0–1023
  Serial.println(sensorValue);             // send to p5.js
  delay(50);
}

P5 CODE

let port;
let connectBtn;
let baudrate = 9600;
let lastMessage = "";
let sensorValue = 0;

function setup() {
  createCanvas(400, 400);
  background(220);

  //Setting the global variable port to a new serial port instance inside setup:
  port = createSerial();

  // we can open ports we have used previously without user interaction
  let usedPorts = usedSerialPorts(); //array of used ports
  if (usedPorts.length > 0) {  
    port.open(usedPorts[0], baudrate); //if any used port is in the array, open that port with 9600 baudrate
  }

  // any other ports (new ones) can be opened via a dialog after user interaction (see connectBtnClick below)
  connectBtn = createButton("Connect to Arduino");
  connectBtn.position(width/2, 270);
  connectBtn.mousePressed(connectBtnClick);

}

function draw() {
  background("white");
 
  // Read from the serial port. This is a non-blocking function. If a full line has come in (ending in \n), it returns that text. If the full line is not yet complete, it returns an empty string "" instead.
  let str = port.readUntil("\n");
  if (str.length > 0) {   // if str -a string- has any characters
    // print(str);
    lastMessage = str;
    sensorValue = int(lastMessage);  
  }
 
  //draw ellipse mapped to horizontal axis
  let x = map(sensorValue, 0, 1023, 0, width);  
  ellipse(x, height / 2, 40, 40);
 
  // Display the most recent message
  text("Last message: " + lastMessage, 10, height - 20);

  // change button label based on connection status
  if (!port.opened()) {
    connectBtn.html("Connect to Arduino");
  } else {
    connectBtn.html("Disconnect");
  }
}

function connectBtnClick() {
  if (!port.opened()) {
    port.open("Arduino", baudrate);
  } else {
    port.close();
  }
}

 

 

2-Make something that controls the LED brightness from p5

DEMO

IMG_8392 (2)

ARDUINO CODE

// Week 12 Example of bidirectional serial communication

int leftLedPin = 2;
int rightLedPin = 5;

void setup() {
  Serial.begin(9600);

  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(leftLedPin, OUTPUT);
  pinMode(rightLedPin, OUTPUT);

  digitalWrite(leftLedPin, HIGH);
  digitalWrite(rightLedPin, HIGH);
  delay(200);
  digitalWrite(leftLedPin, LOW);
  digitalWrite(rightLedPin, LOW);

  while (Serial.available() <= 0) {
    digitalWrite(LED_BUILTIN, HIGH);
    Serial.println("0,0");
    delay(300);
    digitalWrite(LED_BUILTIN, LOW);
    delay(50);
  }
}

void loop() {
  while (Serial.available()) {
    digitalWrite(LED_BUILTIN, HIGH);

    int left = Serial.parseInt();
    int right = Serial.parseInt();

    if (Serial.read() == '\n') {

      // -----------------------
      // ONLY CHANGE IS HERE:
      // -----------------------
      digitalWrite(leftLedPin, left);     // left stays ON/OFF
      analogWrite(rightLedPin, right);    // right is now BRIGHTNESS (0–255)
      // -----------------------

      int sensor = analogRead(A0);
      delay(5);
      int sensor2 = analogRead(A1);
      delay(5);
      Serial.print(sensor);
      Serial.print(',');
      Serial.println(sensor2);
    }
  }
  digitalWrite(LED_BUILTIN, LOW);
}

p5 CODE

let port; // making a var to hold the serial port
let baudrate = 9600; // speed for talking to arduino
let brightnessSlider; // slider to pick brightness
let smoothBrightness = 0; //transition into the brightness instead of jumping

function setup() {
  createCanvas(400, 200); // just making a small canvas for ui
  textSize(18); // bigger test

  brightnessSlider = createSlider(0, 255, 0); // slider from 0 to full bright
  brightnessSlider.position(20, 80); // where it shows up on screen
  brightnessSlider.style('width', '200px'); // make it a bit wider

  port = createSerial(); // create a serial object so we can connect to arduino

  let used = usedSerialPorts(); // check if we already used a port before
  if (used.length > 0) {
    port.open(used[0], baudrate); // auto connect to the last used port
  }
}

function setupSerial() {
  if (!port.opened()) { // if no connection yet
    port.open("Arduino", baudrate); // try to open one
  } else {
    port.close(); // if already open then close it (toggle)
  }
}

function draw() {
  background(240); // light grey

  if (!port.opened()) {
    text("Press SPACE to connect", 20, 30); // tell the user what to do
  } else {
    text("Connected!", 20, 30); // connection message
  }

  let target = brightnessSlider.value(); // get the slider value

  // do transitional brightness
  smoothBrightness = lerp(smoothBrightness, target, 0.07);
 

  text("Brightness: " + int(smoothBrightness), 20, 70); // show the number

  // actually send the brightness to the arduino
  if (port.opened()) {
    let sendString = "0," + int(smoothBrightness) + "\n"; // left=0 right=smooth
    port.write(sendString); // send it over serial
  }
}

function keyPressed() {
  if (key === " ") {
    setupSerial(); // hitting space toggles the port connection
  }
}

3-Take the gravity wind example (https://editor.p5js.org/aaronsherwood/sketches/I7iQrNCul) and make it so every time the ball bounces one led lights up and then turns off, and you can control the wind from one analog sensor

ARDUINO CODE

void setup() {
  pinMode(2, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  int sensorValue = analogRead(A1);
  Serial.println(sensorValue);

  //check for bounce
  if (Serial.available() > 0) {
    //if 1, light up led
    if (Serial.parseInt() == 1) {            
      digitalWrite(2, HIGH);
      delay(100);                          
      digitalWrite(2, LOW);
    }
  }
  delay(10);
}

P5.JS CODE

let velocity;
let gravity;
let position;
let acceleration;
let wind;
let drag = 0.99;
let mass = 50;
let port;
let connectBtn;
let baudrate = 9600;
let lastMessage = "";
let sensorValue = 0;

function setup() {
  createCanvas(640, 360);
  noFill();
  position = createVector(width / 2, 0);
  velocity = createVector(0, 0);
  acceleration = createVector(0, 0);
  gravity = createVector(0, 0.5 * mass);
  wind = createVector(0, 0);

  //Setting the global variable port to a new serial port instance inside setup:
  port = createSerial();

 
  // we can open ports we have used previously without user interaction
  let usedPorts = usedSerialPorts(); //array of used ports
  if (usedPorts.length > 0) {  
    port.open(usedPorts[0], baudrate); //if any used port is in the array, open that port with 9600 baudrate
  }
// any other ports (new ones) can be opened via a dialog after user interaction (see connectBtnClick below)
  connectBtn = createButton("Connect to Arduino");
  connectBtn.position(width/2, 270);
  connectBtn.mousePressed(connectBtnClick);
}

function draw() {
  background(255);
 
  // Read from the serial port. This is a non-blocking function. If a full line has come in (ending in \n), it returns that text. If the full line is not yet complete, it returns an empty string "" instead.
  let str = port.readUntil("\n");
  if (str.length > 0) {   // if str -a string- has any characters
    // print(str);
    lastMessage = str.trim();
    sensorValue = int(lastMessage);    
  }
 

  //wind controlled by analog sensor
  wind.x = map(sensorValue, 0, 1023, -1, 1);
  console.log("Sensor value: " + sensorValue);
 

  applyForce(wind);
  applyForce(gravity);

  velocity.add(acceleration);
  velocity.mult(drag);
  position.add(velocity);
  acceleration.mult(0);

  ellipse(position.x, position.y, mass, mass);

  // Bounce detection
  if (position.y > height - mass / 2) {
    velocity.y *= -0.9; // Dampening
    position.y = height - mass / 2;

    //send bounce signal to Arduino
    port.write("1\n");
  }
// Display the most recent message
  text("Last message: " + lastMessage, 10, height - 20);

  // change button label based on connection status
  if (!port.opened()) {
    connectBtn.html("Connect to Arduino");
  } else {
    connectBtn.html("Disconnect");
  }
}

function applyForce(force){
  // Newton's 2nd law: F = M * A
  // or A = F / M
  let f = p5.Vector.div(force, mass);
  acceleration.add(f);
}

function keyPressed(){
  if (keyCode==LEFT_ARROW){
    wind.x=-1;
  }
  if (keyCode==RIGHT_ARROW){
    wind.x=1;
  }
  if (key==' '){
    mass=random(15,80);
    position.y=-mass;
    velocity.mult(0);
  }
}

function connectBtnClick() {
  if (!port.opened()) {
    port.openDialog(); // user selects port
  } else {
    port.close();
  }
}

Final Project Proposal: Plant Care Station

The final project idea I have in mind is to make a connection between the Arduino and p5.js to take care of plants. Through buttons the user can fill the meter for water (through a blue buttons), then add fertilizer (yellow button), to trim (red button), to move sunlight closeness(yellow buttons one for arrow up one for arrow down).

You can even get a score or a rating based on how well you took care of the plant. Checking each metric. The Arduino part would be multiple buttons and a box that covers these buttons with larger buttons on the wooden box (design is inspired by the beat hoven project displayed in class).

ARDUINO

p5

My project idea is to make a game or maybe some kind of art tool that uses a tilt controller I’m going to build myself. I might use an Adafruit Circuit Playground to be the controller, since it has an accelerometer inside to sense which way you’re tilting it. I plan to use the Arduino IDE to program the Circuit Playground and get the accelerometer data. Then, I want to send that data to my computer and use p5.js to make the actual game or art program. I’m not totally sure what the final thing will be, but it could be a maze game where you tilt to move the character, a simple pilot game, or a cool art program where the tilt moves the brush around instead of using arrow keys.

Main Concept

The main concept for my final project is the “Lock In Buddy.” It basically never lets you stop studying. Your laptop acts as the monitor, and the system uses Arduino sensors and p5 to track your behavior while you are studying. If it detects your phone, it triggers a super loud alarm. If it senses that you’re leaving the table using a distance sensor, it activates the speaker and says, “Come back to the desk. You gotta lock in!” I also want to incorporate the Pomodoro technique, where you study for 25 minutes and take a 5-minute break. A student can press a physical button to start the timer, and press it again to stop it. At the end, the system will give you a score based on how distracted you were by environmental variables, like looking at people walking by, eating, or any other interruptions. Essentially, it becomes your study buddy until you graduate.

 

Lock In Buddy will have these features: 

• • Phone detection alarm 

It will detect when the user picks up a phone, uses, or brings their phone to a nearby desk. The monitor is always watching the user to make sure that they don’t use their phone. 

• • Leaving the desk detection 

The distance sensor detects when the user moves away from the study area. It plays a warning voice message saying “you gotta lock in buddy. Or you will become homeless”. 

• • Real time distraction detection 

The system detects whether you’re being distracted by environmental conditions. Those include looking at people passing by, eating, chair movement, or noise.

• • Pomodoro timer with physical buttons 

Users can press the button to start, pause and stop the Pomodoro session. Also, it will record how long you have been studying for, which is going to be recorded for the scoring system as well. 

• • Focus score generation 

P5 will calculate the number of distractions, phone usage count, time away from desk, noise levels, and the number of successful Pomodoro sessions.

 

How to integrate p5 and Arduino

Phone detection + alarm: 

• • p5.js + Webcam + ML5 COCO-SSD 

Or 

• • Arduino light sensor + phone jail box

• • Start playing the warning alarm saying “Lock in” in p5

 

Eating or talking: 

• • Sound sensor

 

Pomodoro Timer with physical buttons: 

• • Buttons with arduino

 

Leaving desk: 

• • Ultrasonic distance sensor 

 

Focus Score generation: 

• • Arduino continuously reads 
    • Light sensor → phone removed 
    • Ultrasonic sensor → left desk 
    • Sound sensor → eating/talking 
    • Button → start/stop Pomodoro
  • Send those data to p5 and calculate the score