Serial Communication Assignment

Exercise 1

By using a potentiometer, we were able to move the ball across the screen.

Arduino Code

void setup() {
  Serial.begin(9600);
  while (Serial.available() <= 0) {
    Serial.println("0"); // send a starting message
    delay(300);              // wait 1/3 second
  }
}
void loop() {
  while (Serial.available() > 0) {
    // read the incoming byte:
    int inByte = Serial.read();
    int sensorValue = analogRead(A0);
    Serial.print(sensorValue);
    Serial.println();
  }
}

P5JS code

let serial; // variable to hold an instance of the serialport library
let portName = "/dev/tty.usbmodem14201"; // fill in your serial port name here
let yPos;
let onOff=0;
let xval = 0;

function setup() {
  createCanvas(640, 480);
  serial = new p5.SerialPort(); // make a new instance of the serialport library
  serial.on("list", printList); // set a callback function for the serialport list event
  serial.on("connected", serverConnected); // callback for connecting to the server
  serial.on("open", portOpen); // callback for the port opening
  serial.on("data", serialEvent); // callback for when new data arrives
  serial.on("error", serialError); // callback for errors
  serial.on("close", portClose); // callback for the port closing

  serial.list(); // list the serial ports
  serial.open(portName); // open a serial port
  yPos=height/2;
}

function draw() {
  background(255);
}

// get the list of ports:
function printList(portList) {
  // portList is an array of serial port names
  for (let i = 0; i < portList.length; i++) {
    // Display the list the console:
    print(i + " " + portList[i]);
  }
}

function serverConnected() {
  print("connected to server.");
}

function portOpen() {
  print("the serial port opened.");
}

function serialEvent() {
  // read a string from the serial port
  // until you get carriage return and newline:
  let inString = serial.readLine();
  //check to see that there's actually a string there:
  if (inString.length > 0) {
    let inVal = parseInt(inString)
    xval = map(inVal, 1023, 0, 0, width)
  }

  serial.write(onOff);
}

function serialError(err) {
  print("Something went wrong with the serial port. " + err);
}

function portClose() {
  print("The serial port closed.");
}

Exercise 2

Now in the opposite direction, we used arrow keys on the computer to modify the brightness of an LED in Arduino

Arduino Code

void setup() {
  Serial.begin(9600);
  while (Serial.available() <= 0) {
    Serial.println("0"); // send a starting message
    delay(300);              // wait 1/3 second
  }
}
void loop() {
  while (Serial.available() > 0) {
    // read the incoming byte:
    int inByte = Serial.read();
    analogWrite(3, inByte);
    Serial.print("ye");
    Serial.println();
  }
}

P5JS Code

let serial; // variable to hold an instance of the serialport library
let portName = "/dev/tty.usbmodem14201"; // fill in your serial port name here
let yPos;
let onOff=0;
let xval = 0;
let outVal = 0;

function setup() {
  createCanvas(640, 480);
  serial = new p5.SerialPort(); // make a new instance of the serialport library
  serial.on("list", printList); // set a callback function for the serialport list event
  serial.on("connected", serverConnected); // callback for connecting to the server
  serial.on("open", portOpen); // callback for the port opening
  serial.on("data", serialEvent); // callback for when new data arrives
  serial.on("error", serialError); // callback for errors
  serial.on("close", portClose); // callback for the port closing

  serial.list(); // list the serial ports
  serial.open(portName); // open a serial port
  yPos=height/2;
}

function keyReleased() {
  if (keyCode === LEFT_ARROW) {
    outVal = max(outVal - 10, 0) ;
  } else if(keyCode === RIGHT_ARROW) {
    outVal = min(outVal+10, 255);
  }
  return false;
}

function draw() {
  background(255);
}

// get the list of ports:
function printList(portList) {
  // portList is an array of serial port names
  for (let i = 0; i < portList.length; i++) {
    // Display the list the console:
    print(i + " " + portList[i]);
  }
}

function serverConnected() {
  print("connected to server.");
}

function portOpen() {
  print("the serial port opened.");
}

function serialEvent() {
  // read a string from the serial port
  // until you get carriage return and newline:
  let inString = serial.readLine();
  serial.write(outVal);
}

function serialError(err) {
  print("Something went wrong with the serial port. " + err);
}

function portClose() {
  print("The serial port closed.");
}

Exercise 3

Combining the ball p5js example with a potentiometer, we were able to create an interactive arduino-p5js experience.

Arduino Code

void setup() {
  Serial.begin(9600);
  while (Serial.available() <= 0) {
    Serial.println("0"); // send a starting message
    delay(300);              // wait 1/3 second
  }
}
void loop() {
  while (Serial.available() > 0) {
    // read the incoming byte:
    int inByte = Serial.read();
    analogWrite(3, inByte);
    int sensorValue = analogRead(A0);
    Serial.print(sensorValue);
    Serial.println();
  }
}

P5JS Code

let serial; // variable to hold an instance of the serialport library
let portName = "/dev/tty.usbmodem14201"; // fill in your serial port name here
let velocity;
let gravity;
let position;
let acceleration;
let wind;
let drag = 0.99;
let mass = 50;
let hDampening;
let inVal = 0;
let outVal = 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);
  hDampening=map(mass,15,80,.98,.96);
  serial = new p5.SerialPort(); // make a new instance of the serialport library
  serial.on("list", printList); // set a callback function for the serialport list event
  serial.on("connected", serverConnected); // callback for connecting to the server
  serial.on("open", portOpen); // callback for the port opening
  serial.on("data", serialEvent); // callback for when new data arrives
  serial.on("error", serialError); // callback for errors
  serial.on("close", portClose); // callback for the port closing
    serial.list(); // list the serial ports
  serial.open(portName); // open a serial port
}

function draw() {
  background(255);
  if (!keyPressed){
    wind.x=0;
    velocity.x*=hDampening;
  }
  applyForce(wind);
  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;
    }
 outVal = position.y >= height-mass/2-5 ? 255 : 0;
 wind.x = map(inVal, 0, 1023, -5, 5)*hDampening;
}

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==' '){
    mass=random(15,80);
    position.y=-mass;
    velocity.mult(0);
  }
}

Video