/* * Project 6: ESP32 RGB LED Web Server * Control an RGB LED from a browser color picker using PWM. * * Pin map: * GPIO 13 -> Red anode (through 220 ohm) * GPIO 12 -> Green anode (through 220 ohm) * GPIO 14 -> Blue anode (through 220 ohm) * Common cathode -> GND * * Libraries: WiFi (built-in) * Serial: 115200 baud */ // Load Wi-Fi library #include // 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); // Decode HTTP GET value String redString = "0"; String greenString = "0"; String blueString = "0"; int pos1 = 0; int pos2 = 0; int pos3 = 0; int pos4 = 0; // Variable to store the HTTP request String header; // Red, green, and blue pins for PWM control const int redPin = 13; // 13 corresponds to GPIO13 const int greenPin = 12; // 12 corresponds to GPIO12 const int bluePin = 14; // 14 corresponds to GPIO14 // Setting PWM frequency and bit resolution (ESP32 Core v3.x+ API) // Same two settings as Project 3, applied to three pins instead of one. // The core allocates an internal PWM channel per pin for you. const int freq = 5000; // Bit resolution 2^8 = 256 const int resolution = 8; // 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); delay(500); Serial.println(); Serial.println("=============================================="); Serial.println(" Project 6: ESP32 RGB LED Web Server"); Serial.println("=============================================="); Serial.printf ("RGB LED -> R:GPIO%d G:GPIO%d B:GPIO%d\n", redPin, greenPin, bluePin); // Enable PWM on each color pin: one call per pin sets up the timer, // picks a free channel, and routes it to the GPIO. ledcAttach(redPin, freq, resolution); ledcAttach(greenPin, freq, resolution); ledcAttach(bluePin, freq, resolution); // Connect to Wi-Fi network with SSID and password Serial.print("Connecting to Wi-Fi: "); 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("Wi-Fi connected!"); Serial.print("Open this address in your browser: http://"); Serial.println(WiFi.localIP()); Serial.println("----------------------------------------------"); server.begin(); } void loop(){ WiFiClient client = server.available(); // Listen for incoming clients if (client) { // If a new client connects, currentTime = millis(); previousTime = currentTime; String currentLine = ""; // holds incoming data from the client while (client.connected() && currentTime - previousTime <= timeoutTime) { currentTime = millis(); if (client.available()) { // if there's bytes to read from the client, char c = client.read(); // read a byte, then header += c; if (c == '\n') { // if the byte is a newline character if (currentLine.length() == 0) { // Send the HTTP response header client.println("HTTP/1.1 200 OK"); client.println("Content-type:text/html"); client.println("Connection: close"); client.println(); // Display the HTML web page (color picker) client.println(""); client.println(""); client.println(""); client.println(""); client.println(""); client.println("

ESP Color Picker

"); client.println("Change Color "); client.println("

"); client.println(""); client.println(); // Request sample: /?r201g32b255& -> Red=201 Green=32 Blue=255 if(header.indexOf("GET /?r") >= 0) { pos1 = header.indexOf('r'); pos2 = header.indexOf('g'); pos3 = header.indexOf('b'); pos4 = header.indexOf('&'); redString = header.substring(pos1+1, pos2); greenString = header.substring(pos2+1, pos3); blueString = header.substring(pos3+1, pos4); // Clear, readable log of the chosen color Serial.printf("[WEB] Color set -> R:%s G:%s B:%s\n", redString.c_str(), greenString.c_str(), blueString.c_str()); // In Core v3.x+ the first argument is the GPIO pin, not a channel ledcWrite(redPin, redString.toInt()); ledcWrite(greenPin, greenString.toInt()); ledcWrite(bluePin, blueString.toInt()); } break; } else { currentLine = ""; } } else if (c != '\r') { currentLine += c; } } } // Clear the header variable header = ""; // Close the connection client.stop(); } }