Week 12 – Serial Communication

Exercise 1:

Ellipse in p5 move on the horizontal axis, in the middle of the screen, and nothing on Arduino is controlled by p5

let rVal = 0;
let alpha = 255;
let left = 0; // True (1) if mouse is being clicked on left side of screen
let right = 0; // True (1) if mouse is being clicked on right side of screen

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

function draw() {
  // one value from Arduino controls the background's red color
  background(255)

  // the other value controls the text's transparency value
  fill(255, 0,0)

  if (!serialActive) {
    text("Press Space Bar to select Serial Port", 20, 30);
  } else {
    text("Connected", 20, 30);
    // Print the current values
    text('rVal = ' + str(rVal), 20, 50);
    text('alpha = ' + str(alpha), 20, 70);
  }

  // click on one side of the screen, one LED will light up
  // click on the other side, the other LED will light up
  if (mouseIsPressed) {
    if (mouseX > rVal-50 && mouseX < rVal+50 && mouseY > height/2-50 && mouseY < height/2+50) {
      right = 1;
    } 
  } else {
    right = 0;
  }
  ellipse(rVal, height/2, 50,50)
}

function keyPressed() {
  if (key == " ") {
    // important to have in order to start the serial connection!!
    setUpSerial();
  }
}

// This function will be called by the web-serial library
// with each new line of data. The serial library reads
// the data until the newline and then gives it to us through
// this callback function
function readSerial(data) {
  ////////////////////////////////////
  //READ FROM ARDUINO HERE
  ////////////////////////////////////

  if (data != null) {
    // make sure there is actually a message
    // split the message
    let fromArduino = split(trim(data), ",");
    // if the right length, then proceed
    if (fromArduino.length == 2) {
      // only store values here
      // do everything with those values in the main draw loop
      
      // We take the string we get from Arduino and explicitly
      // convert it to a number by using int()
      // e.g. "103" becomes 103
      rVal = int(fromArduino[0]);
      alpha = int(fromArduino[1]);
    }

    //////////////////////////////////
    //SEND TO ARDUINO HERE (handshake)
    //////////////////////////////////
    let sendToArduino = left + "," + right + "\n";
    writeSerial(sendToArduino);
  }
}

 

Exercise 2:

Something that controls the LED brightness from p5

let rVal = 0;
let alpha = 255;
let left = 0; // True (1) if mouse is being clicked on left side of screen
let right = 0; // True (1) if mouse is being clicked on right side of screen

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

function draw() {
  // one value from Arduino controls the background's red color
  background(map(rVal, 0, 1023, 0, 255), 255, 200);

  // the other value controls the text's transparency value
  fill(255, 0, 255, map(alpha, 0, 1023, 0, 255));

  if (!serialActive) {
    text("Press Space Bar to select Serial Port", 20, 30);
  } else {
    text("Connected", 20, 30);
    // Print the current values
    text('rVal = ' + str(rVal), 20, 50);
    text('alpha = ' + str(alpha), 20, 70);
  }


  // click on one side of the screen, one LED will light up
  // click on the other side, the other LED will light up
  if (mouseIsPressed) {
    if (mouseX <= width / 2) {
      left = 1;
    } else {
      right = 1;
    }
  } else {
    left = right = 0;
  }
}

function keyPressed() {
  if (key == " ") {
    // important to have in order to start the serial connection!!
    setUpSerial();
  }
}


function readSerial(data) {
  ////////////////////////////////////
  //READ FROM ARDUINO HERE
  ////////////////////////////////////

  if (data != null) {
    // make sure there is actually a message
    // split the message
    let fromArduino = split(trim(data), ",");
    // if the right length, then proceed
    if (fromArduino.length == 2) {
      // only store values here
      // do everything with those values in the main draw loop
      
      // We take the string we get from Arduino and explicitly
      // convert it to a number by using int()
      // e.g. "103" becomes 103
      rVal = int(fromArduino[0]);
      alpha = int(fromArduino[1]);
    }

    //////////////////////////////////
    //SEND TO ARDUINO HERE (handshake)
    //////////////////////////////////
    let sendToArduino = left + "," + right + "\n";
    writeSerial(sendToArduino);
  }
}

 

Exercise 3:

Bouncing ball

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, 50);
  }
  else 
  {
    text("check the light.", 20, 50);
  
  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();
  }
}
// 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);
  }
}

in Arduino:

int leftLedPin = 2;

void setup() {
  // Start serial communication so we can send data
  // over the USB connection to our p5js sketch
  Serial.begin(9600);
  pinMode(LED_BUILTIN, OUTPUT);

  // Outputs on these pins
  pinMode(leftLedPin, OUTPUT);

  // Blink them so we can check the wiring
  digitalWrite(leftLedPin, HIGH);
  delay(200);
  digitalWrite(leftLedPin, LOW);



  // 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() {
  while (Serial.available()) {
    digitalWrite(LED_BUILTIN, HIGH); // led on while receiving data

    int left = Serial.parseInt();
    if(left>=330){
       digitalWrite(leftLedPin, HIGH);
}
  
    if (Serial.read() == '\n') {
      digitalWrite(leftLedPin, left);
      int sensor = analogRead(A0);
      sensor = map(sensor,0,1023,-1,1);
      Serial.println(sensor);

    }
  }
  digitalWrite(leftLedPin, LOW);
}

 

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