In houses we have electrical appliances, for example, lamps, washing machines, heaters, and other appliances that we only need to turn on or off. In this section, we will learn how to control a lamp connected to the Raspberry Pi Zero, using electrical circuits for interfacing the signal. We will use an optocoupler such as MOC3011, and a Triac. The following figure shows the circuit of the application:

Here we have the final project connected to the Raspberry pi Zero:

Here we have the JavaScript code for controlling the device:

// Modules 
var express = require('express'); 
 
// Express app 
var app = express(); 
 
// Pin 
var lampPin = 12; 

// Use public directory 
app.use(express.static('public')); 
 
// Routes 
app.get('/', function (req, res...