/*

  Samyam Lamichhane

  Serial Communication

  Intro-To-Interactive-Media

  Nov 20, 2022 Sun.

  * Description *

    - Potentiometer can be used to control the x-coordinates of the ball on the canvas

​

  * DISCLAIMER *

  Serial-port code adapted from: https://editor.p5js.org/mangtronix/sketches/vQzE2Yhpj

  * Schematics *

  https://github.com/declansam/SerialComm_Exercises/blob/main/ex_1/ex_1_pot_read_schem_Samyam.png

​

  * Pair it with *

  https://github.com/declansam/SerialComm_Exercises/blob/main/ex_1/ex_1_pot_to_p5js.ino

*/

​

​

​

// Global variables added

let h = 1000;          // Canvas height

let w = 1000;          // Canvas width

let ellipse_height = 50;

let ellipse_width = 50;

​

​

// variable to hold an instance of the p5.webserial library:

const serial = new p5.WebSerial();

// HTML button object:

let portButton;

let inData;                   // for incoming serial data

let outByte = 0;              // for outgoing data

​

function setup() 

{

  createCanvas(w, h);          // make the canvas

  // check to see if serial is available:

  if (!navigator.serial) {

    alert("WebSerial is not supported in this browser. Try Chrome or MS Edge.");

  }

  // if serial is available, add connect/disconnect listeners:

  navigator.serial.addEventListener("connect", portConnect);

  navigator.serial.addEventListener("disconnect", portDisconnect);

  // check for any ports that are available:

  serial.getPorts();

  // if there's no port chosen, choose one:

  serial.on("noport", makePortButton);

  // open whatever port is available:

  serial.on("portavailable", openPort);

  // handle serial errors:

  serial.on("requesterror", portError);

  // handle any incoming serial data:

  serial.on("data", serialEvent);

  serial.on("close", makePortButton);

}

​

​

function draw() 

{

​

  background(50);

  fill(255);

​

  textSize(25);

  text("Raw sensor value: " + inData, 30, 50);

  // ------------------ Ellipse Values ----------------

  let max_pot_reading = 255;

  let map_error_corr = ellipse_width/2;

  // X-coordinate is scaled based on the readings from potentiometer

  let scaled_x_pos = map(inData, 0, max_pot_reading, map_error_corr, (w-map_error_corr));

  // Draw ellipse using the values determined above

  draw_ellipse(scaled_x_pos, (h/2 - map_error_corr), ellipse_height, ellipse_width);

  // Text Display on the right side of the canvas

  let rounded_x_pos = round(scaled_x_pos, 2);          // Data rounded upto 2 decimal places

  textSize(25);

  fill("white");

  text("Scaled X-position: " + rounded_x_pos, (w/2 + 150), 50);

}

​

​

​

// Function to draw an ellipse

// Aruguments; (x, y) coordinates && width and height

function draw_ellipse(x, y, w_, h_)

{

  fill("red");

  ellipse(x, y, w_, h_);

}

​

​

​

​

// if there's no port selected, 

// make a port select button appear:

function makePortButton() {

  // create and position a port chooser button:

  portButton = createButton("choose port");

  portButton.position(10, 10);

  // give the port button a mousepressed handler:

  portButton.mousePressed(choosePort);

}

// make the port selector window appear:

function choosePort() {

  if (portButton) portButton.show();

  serial.requestPort();

}

// open the selected port, and make the port 

// button invisible:

function openPort() {

  // wait for the serial.open promise to return,

  // then call the initiateSerial function

  serial.open().then(initiateSerial);

  // once the port opens, let the user know:

  function initiateSerial() {

    console.log("port open");

  }

  // hide the port button once a port is chosen:

  if (portButton) portButton.hide();

}

// pop up an alert if there's a port error:

function portError(err) {

  alert("Serial port error: " + err);

}

// read any incoming data as a string

// (assumes a newline at the end of it):

function serialEvent() {

  inData = Number(serial.read());

  console.log(inData);

}

// try to connect if a new serial port 

// gets added (i.e. plugged in via USB):

function portConnect() {

  console.log("port connected");

  serial.getPorts();

}

// if a port is disconnected:

function portDisconnect() {

  serial.close();

  console.log("port disconnected");

}

function closePort() {

  serial.close();

}

​

​