Week 12 – Serial Communication (Group Assignment)

void setup() {
  Serial.begin(9600);
  //pinMode(LED_BUILTIN, OUTPUT);

//start the handshake
  while (Serial.available() <= 0) {
    //digitalWrite(LED_BUILTIN, HIGH);
    Serial.println("0,0"); // send a starting message
    delay(300);
    //digitalWrite(LED_BUILTIN, LOW);
    delay(50);

  }
}

void loop() {
  // wait for data from p5 before doing something
  while (Serial.available()) {
     //digitalWrite(LED_BUILTIN, HIGH);
    int isMoving = Serial.parseInt();
    if (Serial.read() == '\n') {
      int photoVal = analogRead(A0); 
      delay(5);
      Serial.println(photoVal);
   }
  }
  //digitalWrite(LED_BUILTIN, LOW);
}

// Initialize variables to store values from Arduino
let rVal = 0; // Stores the received value from Arduino
let xPos = 0; // Stores the mapped x-position value
let rad = 50; // Radius of the ellipse to be drawn

// Setup function - runs once at the beginning
function setup() {
  // Create a canvas with dimensions 400x400
  createCanvas(400, 400);
  // Set text size to 18 pixels
  textSize(18);
}  

// Draw function - runs continuously
function draw() {
  // Set background color to white
  background(255);

  // Check if serial communication is active
  if (!serialActive) {
    // Display message to prompt user to press Space Bar to select Serial Port
    text("Press Space Bar to select Serial Port", 20, 30);
  } else {
    // If serial communication is active, display "Connected" message
    text("Connected", 20, 30);
    
    // Map the received value (rVal) to the x-position within the canvas
    xPos = map(rVal, 0, 900, 0, 400);
    // Display the current received value (rVal)
    text('rVal = ' + str(rVal), 20, 50);
    // Draw an ellipse at the mapped x-position with fixed y-position (200) and radius (rad)
    ellipse(xPos, 200, rad, rad);
    // Display the mapped x-position (xPos)
    text('xPos = ' + str(xPos), 20, 70);
  }
}

// Function to handle key presses
function keyPressed() {
  // Check if Space Bar is pressed
  if (key == " ") {
    // Call setUpSerial() function to start serial connection
    setUpSerial();
  }
}

// Function to read data from Arduino
function readSerial(data) {
  // Check if data is not null
  if (data != null) {
    // Split the received data into an array using comma as delimiter
    let fromArduino = split(trim(data), ",");
    
    // Check if the array contains only one element
    if (fromArduino.length == 1) {
      // Update rVal with the received value from Arduino
      rVal = fromArduino[0];
    }
    
    // Send a handshake message to Arduino
    let sendToArduino = 1 + "\n";
    writeSerial(sendToArduino);
  }
}

Exercise 2: P5 TO ARDUINO COMMUNICATION

Something that controls the LED brightness from p5.

Arduino Code

//Exercise 2 Arduino Code

const int ledPin =9;
int brightness = 0;
void setup() {
  Serial.begin(9600); // This will start serial communication at 9600 bps

  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(ledPin, OUTPUT);
// start the handshake
  while (Serial.available() <= 0) {
    digitalWrite(LED_BUILTIN, HIGH); // on blink when waiting for serial data
    Serial.println("0,0"); // sending a starting message 
    delay(300);            // waiting for the delar
  }
}
void loop() 
{
  // wait for data from p5 before doing something
    while (Serial.available()) 
    {
    digitalWrite(LED_BUILTIN, HIGH); // led on while receiving data
    int brightness = Serial.parseInt(); //get slider value from p5
    Serial.println(brightness); //just to view the value
    
     if (Serial.read() == '\n') {
       analogWrite(ledPin, brightness); // will set brightness of LED
     
      }else
      {
        digitalWrite(LED_BUILTIN, HIGH);
      }
    }
}

P5 Code

//Exercise 2 - P5js Code
let slider;
function setup() {
   createCanvas(400, 400); // Creating canvas of 400x400 pixels
  slider = createSlider("0, 255, 0");
  slider.position(100, height/2); // Set the position of the slider
  slider.style('width', '80px'); // Set the width of the slider 
 
  
  noStroke(); // No stroke for the ellipse initially
}
function draw() {
  
  background(255); // Refresh background on each frame
  
  if (!serialActive) {
    text("Press Space Bar to select Serial Port", 20, 30);
  } else {
    text("Connected", 20, 30);}
}
function keyPressed() {
  if (key == " ") {
    // setting the serial connection!!
    setUpSerial();
  }   
}
// this callback function
function readSerial(data) {
    ////////////////////////////////////
    //READ FROM ARDUINO HERE
    ////////////////////////////////////
    //////////////////////////////////
    //SEND TO ARDUINO HERE (handshake)
    //////////////////////////////////
    console.log(slider.value());
    let sendToArduino = slider.value() + "\n";
    writeSerial(sendToArduino);
  
}

Video Demonstration

 

Schematic

Exercise 3: BI-DIRECTIONAL COMMUNICATION

Every time the ball bounces one led lights up and then turns off, potentiometer is used as the analog sensor to control the wind.

Arduino Code

//Exercise 3 Arduino Code

const int poten_pin = A0;
const int ledPin = 2;
void setup() {
 Serial.begin(9600); // Start serial communication at 9600 bps
 pinMode(LED_BUILTIN, OUTPUT);
 pinMode(ledPin, OUTPUT);
 pinMode(poten_pin, INPUT);
 // start the handshake
 while (Serial.available() <= 0) {
   digitalWrite(LED_BUILTIN, HIGH); // on/blink while waiting for serial data
   Serial.println("0,0"); // send a starting message
   delay(300);            // wait 1/3 second
   digitalWrite(LED_BUILTIN, LOW);
   delay(50);
 }
}
void loop()
{
 // wait for data from p5 before doing something
   while (Serial.available())
   {
     digitalWrite(LED_BUILTIN, HIGH);
     digitalWrite(ledPin, LOW);
//read the position of ball from p5
     int position = Serial.parseInt();
  
     if (Serial.read() == '\n') {
       // Read potentiometer value
     int sensorValue = analogRead(poten_pin);
     //send value to p5
     Serial.println(sensorValue);
     }
//if ball is touching the ground i.e. height is zero, turn LED on
     if (position == 0)
     {
       digitalWrite(ledPin, HIGH);
     }
     else{
       digitalWrite(ledPin, LOW);
     }
   }
     digitalWrite(LED_BUILTIN, LOW);
   }

p5 Code

//Exercise 3 - P5js Code

let velocity;
let gravity;
let position;
let acceleration;
let breeze;
let drag = 0.99;
let mass = 50;
let heightOfBall = 0;
function setup() {
  createCanvas(640, 360); // Create a canvas of 800x400 pixels
 
  noFill();
  position = createVector(width/2, 0);
  velocity = createVector(0,0);
  acceleration = createVector(0,0);
  gravity = createVector(0, 0.5*mass);
  breeze = createVector(0,0); 
}
function draw() {
  background(215);
  fill(0);
  
  if (!serialActive) {
    text("Press the space bar to select the serial Port", 20, 30);
  }
  else 
  {
    text("Arduino is connected! Press b to jump.", 20, 30);
  
  applyForce(breeze);
  applyForce(gravity);
  velocity.add(acceleration);
  velocity.mult(drag);
  position.add(velocity);
  acceleration.mult(0);
  ellipse(position.x,position.y,mass,mass);
    
  if (position.y > height-mass/2) {
      velocity.y *= -0.9;  // A little dampening when hitting the bottom
      position.y = height-mass/2;
    
    heightOfBall = 0;
    
    } 
    else {
      heightOfBall = 1;
    }
  }
}
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 (key == " ") {
    // important to have in order to start the serial connection!!
    setUpSerial();
  }   
  else if (key=='b'){
    mass=random(15,80);
    position.y=-mass;
    velocity.mult(0);
  }
}
// this callback function
function readSerial(data) {
    ////////////////////////////////////
    //READ FROM ARDUINO HERE
    ////////////////////////////////////
  
     if (data != null) {
    // make sure there is actually a message
    
    let fromArduino = split(trim(data), ",");
    
       // if the right length, then proceed
    if (fromArduino.length == 1) {
//sensor value is the input from potentiometer
      let sensorVal = int(fromArduino[0]);
      
//potentiometer value ranges from 0 - 1023
//for values less than 400,wind blows to right
      if (sensorVal < 400){
        breeze.x=1
      }
//if value between 400 and 500, wind stops so ball stops
      else if(sensorVal >= 400 && sensorVal < 500){
        breeze.x = 0
      }
//if value greater than 500, wind blows to left
      else {
        breeze.x = -1
      }
          //////////////////////////////////
          //SEND TO ARDUINO HERE (handshake)
          //////////////////////////////////
    }
//height of ball sent to arduino to check if ball on floor or not
    let sendToArduino = heightOfBall  + "\n";
    writeSerial(sendToArduino);
  }
}

Schematic

Video Demonstration