Program for IoT Part 2 ⏱

Getting Started with a Web Interface to the IoT Device

Programming a Web-enabled IoT Device

Program the Particle IoT Device

1. Create a new program in Particle build.

2. Connect the temperature and humidity sensor to D2, connect the LED to A4, and connect your Argon device to your computer.

3. Include the "GROVE_TEMPERATURE_AND_HUMIDITY_SENSOR" and "Grove_ChainableLED" libraries in your program as we have done before.

4. Copy and paste the code below (except of the #include parts) into your program.

// This #include statement was automatically added by the Particle IDE.
#include <Grove_ChainableLED.h>

// This #include statement was automatically added by the Particle IDE.
#include <Grove_Temperature_And_Humidity_Sensor.h>

ChainableLED leds(A4, A5, 1);
DHT dht(D2);
double temp_dbl, humidity_dbl;
bool ledOn = false;

void setup() {
    //for the LED
    leds.setColorHSB(0, 0.0, 0.0, 0.0);
    Particle.function("toggleLed", toggleLed);
    //for the temp and humidity
    Particle.variable("temp", temp_dbl);
    Particle.variable("humidity", humidity_dbl);

void loop() {
    float temp, humidity;
    temp = dht.getTempFarenheit();
    humidity = dht.getHumidity();
    temp_dbl = temp;
    humidity_dbl = humidity;

bool toggleLed(String args) {
    ledOn = !ledOn;
    if (ledOn) {
        leds.setColorHSB(0, 0.0, 1.0, 0.5);
    else {
        leds.setColorHSB(0, 0.0, 0.0, 0.0);
    return ledOn;

5. Save, Verify, and Flash the code to the Argon board.

6. Open the Console from particle build, select "my devices", and select your Argon.

7. Get the temp and humidity variables to check if all is working. Call the "toggleLed" function to ensure the light toggles.

Program the Web Interface

1. Create a new replit program for HTML/CSS/JavaScript.

2. Copy and paste the following for your `index.html` file.

<!DOCTYPE html>

	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width">
	<title>IoT Test</title>
	<link href="style.css" rel="stylesheet" type="text/css" />

	<div id="login">
		<h3>Sign In to Access the IoT Device</h3>
		<input id="username">
		<input type="password" id="password">
		<button onclick="login()">Login</button>
	<div id="iot-control" style="display: none;">
		<div id="temp">Loading...</div>
		<div id="light"></div>
		<button onclick="toggleLight()">Toggle Light</button>
	<script type="text/javascript" src="">
	<script src="script.js"></script>


3. Copy and paste the following for your `script.js` file.

var particle = new Particle();
var token;

function login() {
		username: document.querySelector("#username").value,
		password: document.querySelector("#password").value
		function(data) {
			console.log('API call completed on promise resolve: ', data.body.access_token);
			token = data.body.access_token;
			document.querySelector("#login").style.display = "none";
			document.querySelector("#iot-control").style.display = "block";
		function(err) {
			console.log('API call completed on promise fail: ', err);

function displayTemp() {
	particle.getVariable({ deviceId: 'e00fce6872f90e7cbce1b406', name: 'temp', auth: token })
		.then(function(data) {
			document.querySelector("#temp").innerHTML = `The temperature is ${data.body.result} ℉`
		}, function(err) {
			console.log('An error occurred while getting attrs:', err.body);

function toggleLight() {
	particle.callFunction({ deviceId: 'e00fce6872f90e7cbce1b406', name: 'toggleLed', argument: null, auth: token })
		  function(data) {
				document.querySelector("#light").innerHTML = `The light is ${data.body.return_value ? 'on.' : 'off.'}`
		  }, function(err) {
		    console.log('An error occurred:', err);

4. Run your program.

5. Login to your web app with your Particle account.

6. Confirm that the temperature is displayed on your page.

7. Click the `Toggle Light` button and confirm that the light on your device changes and the text on your web app is consistent with the change.

That's it for our first web-enabled IoT experiment 🎉.

★ If you are having any problems, no worry, post in our slack channel. Please share your code when it makes sense or create videos.

For Reference

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