For the first-in-class exercise, we attached a potentiometer to the breadboard and connected Arduino to the P5js sketch. As we adjusted the serial input value of the potentiometer the ellipse moved up and down. We replaced the y coordinate of the ellipse with the incoming serial value to do so.
Here is the link to the video.
Code
P5js
// 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(400, 300); // 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(0);
fill(255);
text("sensor value: " + inData, 30, 50);
ellipse (200, inData, 50, 50)
}
// 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();
}
// 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();
}
Arduino Code
void setup() {
Serial.begin(9600); // initialize serial communications
}
void loop() {
// read the input pin:
int potentiometer = analogRead(A0);
// remap the pot value to fit in 1 byte:
int mappedPot = map(potentiometer, 0, 1023, 0, 255);
// print it out the serial port:
Serial.write(mappedPot);
// slight delay to stabilize the ADC:
delay(1);
// Delay so we only send 10 times per second and don't
// flood the serial connection
delay(100);
}