/********* Rui Santos Complete project details at https://RandomNerdTutorials.com/esp32-relay-module-ac-web-server/ The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. *********/ // Import required libraries #include "WiFi.h" #include "ESPAsyncWebServer.h" // Set to true to define Relay as Normally Open (NO) #define RELAY_NO true // Set number of relays #define NUM_RELAYS 5 // Assign each GPIO to a relay int relayGPIOs[NUM_RELAYS] = {2, 26, 27, 25, 33}; // Replace with your network credentials const char* ssid = "REPLACE_WITH_YOUR_SSID"; const char* password = "REPLACE_WITH_YOUR_PASSWORD"; const char* PARAM_INPUT_1 = "relay"; const char* PARAM_INPUT_2 = "state"; // Create AsyncWebServer object on port 80 AsyncWebServer server(80); const char index_html[] PROGMEM = R"rawliteral(

ESP Web Server

%BUTTONPLACEHOLDER% )rawliteral"; // Replaces placeholder with button section in your web page String processor(const String& var){ //Serial.println(var); if(var == "BUTTONPLACEHOLDER"){ String buttons =""; for(int i=1; i<=NUM_RELAYS; i++){ String relayStateValue = relayState(i); buttons+= "

Relay #" + String(i) + " - GPIO " + relayGPIOs[i-1] + "

"; } return buttons; } return String(); } String relayState(int numRelay){ if(RELAY_NO){ if(digitalRead(relayGPIOs[numRelay-1])){ return ""; } else { return "checked"; } } else { if(digitalRead(relayGPIOs[numRelay-1])){ return "checked"; } else { return ""; } } return ""; } void setup(){ // Serial port for debugging purposes Serial.begin(115200); // Set all relays to off when the program starts - if set to Normally Open (NO), the relay is off when you set the relay to HIGH for(int i=1; i<=NUM_RELAYS; i++){ pinMode(relayGPIOs[i-1], OUTPUT); if(RELAY_NO){ digitalWrite(relayGPIOs[i-1], HIGH); } else{ digitalWrite(relayGPIOs[i-1], LOW); } } // Connect to Wi-Fi WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED) { delay(1000); Serial.println("Connecting to WiFi.."); } // Print ESP32 Local IP Address Serial.println(WiFi.localIP()); // Route for root / web page server.on("/", HTTP_GET, [](AsyncWebServerRequest *request){ request->send_P(200, "text/html", index_html, processor); }); // Send a GET request to /update?relay=&state= server.on("/update", HTTP_GET, [] (AsyncWebServerRequest *request) { String inputMessage; String inputParam; String inputMessage2; String inputParam2; // GET input1 value on /update?relay= if (request->hasParam(PARAM_INPUT_1) & request->hasParam(PARAM_INPUT_2)) { inputMessage = request->getParam(PARAM_INPUT_1)->value(); inputParam = PARAM_INPUT_1; inputMessage2 = request->getParam(PARAM_INPUT_2)->value(); inputParam2 = PARAM_INPUT_2; if(RELAY_NO){ Serial.print("NO "); digitalWrite(relayGPIOs[inputMessage.toInt()-1], !inputMessage2.toInt()); } else{ Serial.print("NC "); digitalWrite(relayGPIOs[inputMessage.toInt()-1], inputMessage2.toInt()); } } else { inputMessage = "No message sent"; inputParam = "none"; } Serial.println(inputMessage + inputMessage2); request->send(200, "text/plain", "OK"); }); // Start server server.begin(); } void loop() { }