Revision as of 15:52, 2 January 2024

Using a real-time communication platform PubNub, data can be exchanged relatively easily between the Arduino and the P5JS via WLAN and the Internet.

For example, the following code below switches the Arduino's on-board LED on and off via a cell phone or other device with an Internet browser.

Board

This example works with most ESP8266 boards. If necessary, only the LED pin would have to be adapted.

It was tested with the following hardware:

• AZDelivery D1 Mini — (LOLIN (WEMOS) D1 R2 & Mini)

PubNub

Register for a free PubNub account and create a new application by simply clicking on the "CREATE NEW APP" button.

There you will find the two PUBkey and SUBkey codes. That's all!

www.pubnub.com

Arduino

Arduino-Libraries

• SPI.h — ?
• ESP8266WiFi.h — ?
• PubNub.h — www.github.com/pubnub/arduino

Arduino-Code

// Arduino + PubNub + P5JS
// pubnub to arduino example: https://github.com/pubnub/arduino-pubnub
// or: https://github.com/pubnub/arduino

#include <SPI.h>
#include <ESP8266WiFi.h>
#include <PubNub.h>

const char* ssid = "myWlanName"; // Add your WlanName here!
const char* password = "myWlanPassWord"; // // Add your WlanPassWord here!

char pubkey[] = "pub-c-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"; // Add your pubkey here!
char subkey[] = "sub-c-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"; // Add your subkey here!
char channel[] = "P1"; 
char uuid[] = "xxxxxxxx-xxxx-4444-9999-xxxxxxxxxxxx";

int ledPin = 2;  // D4
int keyVal = 0;

void setup() {
  Serial.begin(9600);
  delay(10);
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, HIGH);

  // Connecting with Wifi
  Serial.println("");
  Serial.print("Connecting with: ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("Wifi is successfully connected");
  flash(ledPin, 12);

  PubNub.begin(pubkey, subkey);
  random_uuid();
  PubNub.set_uuid(uuid);
  Serial.println("PubNub set up");
}

void loop() {

  Serial.println("Waiting for a message (subscribe)");
  PubSubClient* client = PubNub.subscribe(channel);
  if (!client) {
    Serial.println("Subscription error");
    delay(1000);
    return;
  }

  String msg;
  SubscribeCracker ritz(client);
  while (!ritz.finished()) {
    ritz.get(msg);
    if (msg.length() > 0) {
      Serial.print("Received: ");
      Serial.println(msg);
      keyVal = int(msg[19]);  // 7 = ascii 55 (myString.toInt() returns long)
      Serial.println(keyVal);
      if (keyVal == '1') {
        Serial.println("LED is on");
        digitalWrite(ledPin, LOW);
        delay(5000);
        digitalWrite(ledPin, HIGH);
        delay(100);
        Serial.println("LED is off");
      }
    }
  }

  client->stop();

  delay(1500);

  digitalWrite(ledPin, HIGH);  // turn the LED off by making the voltage LOW
}

void random_uuid() {
  randomSeed(analogRead(4) + millis() * 1024);
  snprintf(uuid,
           sizeof(uuid),
           "%04lx%04lx-%04lx-4444-9999-%04lx%04lx%04lx",
           random(0x10000),
           random(0x10000),
           random(0x10000),
           random(0x10000),
           random(0x10000),
           random(0x10000));
}

void flash(int _ledPin, int times) {
  for (int i = 0; i < times; i++) {
    digitalWrite(_ledPin, LOW);
    delay(100);
    digitalWrite(_ledPin, HIGH);
    delay(100);
  }
}

P5JS

P5JS-Library

<script src="https://cdn.pubnub.com/sdk/javascript/pubnub.4.28.0.js"></script>

P5JS-Code

// Arduino+PubNub+P5JS
// Based on "PubNub setup" by DigitalFuturesOCADU

let signalTime = 500;
let dataServer;
const pubKey = "pub-c-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"; // Add your pubkey here!
const subKey = "sub-c-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"; // Add your subkey here!
const channelName = "P1";
const publisherId = "boo";
const dataReceived = [];
const presenceUpdates = [];

let mx = 100;
let my = 50;

let myButton;
let fSize;
let bPro = 0;
let bTimer = 0;

let photo;

const myMessage = {
  messageId: 1,
  x: 0,
  y: 0,
  token: 0,
  text: "psssst here is a secret message",
  recipient: "crush",
};

function setup() {
  frameRate(15);
  createCanvas(windowWidth, windowHeight);
  fSize = width / 20;
  textSize(fSize);
  textAlign(CENTER, CENTER);
  fill(255);

  myToken = round(random(10000));

  // initialize PubNub
  dataServer = new PubNub({
    publish_key: pubKey,
    subscribe_key: subKey,
    ssl: true,
    uuid: publisherId,
  });

  dataServer.addListener({
    message: readIncoming,
  });
  dataServer.subscribe({
    channels: [channelName],
    withPresence: true,
  });

  window.onbeforeunload = function () {
    dataServer.unsubscribeAll();
    return null;
  };

  myButton = createButton("submit");
  myButton.position(width / 2 - fSize * 6, (height / 10) * 8);
  myButton.size(fSize * 12, fSize * 2);
  myButton.mousePressed(sendMessage);
  myButton.style("opacity", 0.0);
  myButton.show();
}

function draw() {
  background(20, 90, 90);

  fill(255);
  text("Arduino+Pubnub+P5JS", windowWidth / 2, (height / 10) * 2);

  showButton();
}

function showButton() {
  if (bPro == 0) {
    fill(255);
  } else {
    fill(0);
  }
  rect(
    width / 2 - fSize * 6,
    (height / 10) * 8,
    fSize * 12,
    fSize * 2,
    fSize / 2
  );
  if (bPro == 0) {
    fill(0);
  } else {
    fill(255);
  }
  text("Signal", windowWidth / 2, (height / 10) * 8 + fSize);
  if (millis() > bTimer + signalTime) {
    bPro = 0;
  }
}

function readIncoming(inMessage) {
  console.log(inMessage);
  mx = inMessage.message.x;
  my = inMessage.message.y;
  inToken = inMessage.message.token;
}

function sendMessage() {
  bPro = 1;
  bTimer = millis();
  showButton();
  myMessage.x = 1;
  myMessage.token = myToken;

  dataServer.publish({
    channel: channelName,
    message: myMessage,
  });
}