Wifi Comms — ESP32 Project 8.0
Haihai, balik bersama gue ngebahas project-project menggunakan ESP32. Di jurnal sebelomnya kan udah ngebahas tentang koneksi wireless pake Bluetooth, nah sekarang bakal nyoba pake Wifi. Di project kali ini bakal dibahas tentang ESP32 Wifi Comms sebagai controlling device.
Di percobaan ini gue bakal bikin sebuah web server pake ESP32 buat kontrol nyala-mati LED via Wifi. Langsung aja deh gue masuk ke alat dan bahan.
Alat & Bahan
- ESP32
- LED
- Program Arduino IDE
- Breadboard
- Resistor 330 Ohm
- Kabel Jumper
Skema Rangkaian
Nah, kalo komponen-komponen yang dibutuhkan udah siap bisa langsung ngerangkai dulu nih hardware-nya. Rangkaiannya kaya begini:
Pin positif kedua LED dihubungkan dengan pin GPIO26 dan GPIO27 pada ESP32. Pin negatifnya dihubungkan dengan ground.
Setelah rangkaian udah selesai dibuat, bisa langsung buka program Arduino IDE-nya dan mulai ngoding.
The Code
Buat pengujian Wifi pake ESP32 kali ini, gue pake code seperti yang di bawah ini:
// Load Wi-Fi library
#include <WiFi.h>// Replace with your network credentials
const char* ssid = "REPLACE_WITH_YOUR_SSID";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";// Set web server port number to 80
WiFiServer server(80);// Variable to store the HTTP request
String header;// Auxiliar variables to store the current output state
String output26State = "off";
String output27State = "off";// Assign output variables to GPIO pins
const int output26 = 26;
const int output27 = 27;// Current time
unsigned long currentTime = millis();
// Previous time
unsigned long previousTime = 0;
// Define timeout time in milliseconds (example: 2000ms = 2s)
const long timeoutTime = 2000;void setup() {
Serial.begin(115200);
// Initialize the output variables as outputs
pinMode(output26, OUTPUT);
pinMode(output27, OUTPUT);
// Set outputs to LOW
digitalWrite(output26, LOW);
digitalWrite(output27, LOW);// Connect to Wi-Fi network with SSID and password
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
// Print local IP address and start web server
Serial.println("");
Serial.println("WiFi connected.");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
server.begin();
}void loop(){
WiFiClient client = server.available(); // Listen for incoming clientsif (client) { // If a new client connects,
currentTime = millis();
previousTime = currentTime;
Serial.println("New Client."); // print a message out in the serial port
String currentLine = ""; // make a String to hold incoming data from the client
while (client.connected() && currentTime - previousTime <= timeoutTime) { // loop while the client's connected
currentTime = millis();
if (client.available()) { // if there's bytes to read from the client,
char c = client.read(); // read a byte, then
Serial.write(c); // print it out the serial monitor
header += c;
if (c == '\n') { // if the byte is a newline character
// if the current line is blank, you got two newline characters in a row.
// that's the end of the client HTTP request, so send a response:
if (currentLine.length() == 0) {
// HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
// and a content-type so the client knows what's coming, then a blank line:
client.println("HTTP/1.1 200 OK");
client.println("Content-type:text/html");
client.println("Connection: close");
client.println();
// turns the GPIOs on and off
if (header.indexOf("GET /26/on") >= 0) {
Serial.println("GPIO 26 on");
output26State = "on";
digitalWrite(output26, HIGH);
} else if (header.indexOf("GET /26/off") >= 0) {
Serial.println("GPIO 26 off");
output26State = "off";
digitalWrite(output26, LOW);
} else if (header.indexOf("GET /27/on") >= 0) {
Serial.println("GPIO 27 on");
output27State = "on";
digitalWrite(output27, HIGH);
} else if (header.indexOf("GET /27/off") >= 0) {
Serial.println("GPIO 27 off");
output27State = "off";
digitalWrite(output27, LOW);
}
// Display the HTML web page
client.println("<!DOCTYPE html><html>");
client.println("<head><meta name=\"viewport\" content=\"width=device-width, initial-scale=1\">");
client.println("<link rel=\"icon\" href=\"data:,\">");
// CSS to style the on/off buttons
// Feel free to change the background-color and font-size attributes to fit your preferences
client.println("<style>html { font-family: Helvetica; display: inline-block; margin: 0px auto; text-align: center;}");
client.println(".button { background-color: #4CAF50; border: none; color: white; padding: 16px 40px;");
client.println("text-decoration: none; font-size: 30px; margin: 2px; cursor: pointer;}");
client.println(".button2 {background-color: #555555;}</style></head>");
// Web Page Heading
client.println("<body><h1>ESP32 Web Server</h1>");
// Display current state, and ON/OFF buttons for GPIO 26
client.println("<p>GPIO 26 - State " + output26State + "</p>");
// If the output26State is off, it displays the ON button
if (output26State=="off") {
client.println("<p><a href=\"/26/on\"><button class=\"button\">ON</button></a></p>");
} else {
client.println("<p><a href=\"/26/off\"><button class=\"button button2\">OFF</button></a></p>");
}
// Display current state, and ON/OFF buttons for GPIO 27
client.println("<p>GPIO 27 - State " + output27State + "</p>");
// If the output27State is off, it displays the ON button
if (output27State=="off") {
client.println("<p><a href=\"/27/on\"><button class=\"button\">ON</button></a></p>");
} else {
client.println("<p><a href=\"/27/off\"><button class=\"button button2\">OFF</button></a></p>");
}
client.println("</body></html>");
// The HTTP response ends with another blank line
client.println();
// Break out of the while loop
break;
} else { // if you got a newline, then clear currentLine
currentLine = "";
}
} else if (c != '\r') { // if you got anything else but a carriage return character,
currentLine += c; // add it to the end of the currentLine
}
}
}
// Clear the header variable
header = "";
// Close the connection
client.stop();
Serial.println("Client disconnected.");
Serial.println("");
}
}Kalo code-nya udah sesuai dan bener, bisa langsung di-upload ke ESP32-nya nih. Sesudah berhasil connect, bisa dibuka Serial Monitor buat tes program dan rangkaian yang udah dibikin.
Demo
Setelah dibuka serial monitor-nya, kalo ESP32-nya berhasil terhubung sama Wifi, bakal muncul tampilan kurang lebih kaya begini:
Bisa diliat, udah muncul IP address dari ESP32 yang dipake. IP itu bisa dicoba di ketik di web browser
Karena state kedua LED masih mati, jadi displaynya seperti gambar di atas. Karena udah terhubung, bisa langsung dicoba klik tombol salah satu dan amatin hasilnya.
Let’s try it on!
TaDaa!
Keren kan percobaan kali ini. Ini aja baru dipraktekin buat LED yang kecil. Dengan mengimplementasikan project ini, kita bakal bisa ngebuat hal-hal yang lebih hebat lagi kaya home automation. Sekian dulu buat percobaan kali ini, I’m signing out!
