Sending MQTT Data

platformio.ini

@@ -15,3 +15,4 @@ framework = arduino
 lib_deps = 
 	adafruit/DHT sensor library@^1.4.4
 	adafruit/Adafruit Unified Sensor@^1.1.9
+	knolleary/PubSubClient@^2.8

src/main.cpp

@@ -1,7 +1,7 @@
 #include <DHT.h>
 #include <ESP8266WiFi.h>
 #include <ESP8266WiFiMulti.h>  // Include the Wi-Fi-Multi library
-#include <WiFiClientSecure.h>
+#include <PubSubClient.h>
 #include <Wire.h>
 
 ESP8266WiFiMulti wifiMulti;  // Create an instance of the ESP8266WiFiMulti class, called 'wifiMulti'
@@ -9,14 +9,18 @@ ESP8266WiFiMulti wifiMulti;  // Create an instance of the ESP8266WiFiMulti class
 // WiFi connect timeout per AP. Increase when connecting takes longer.
 const uint32_t connectTimeoutMs = 5000;
 
-// Replace with your server's address
-const char* serverAddress = "sensors.tanshu.com";
-const int serverPort = 443;
+// MQTT broker's address and port
+const char* mqttServer = "iot.tanshu.com";
+const int mqttPort = 1883;
 
-// Replace with your DHT sensor pin
+// MQTT broker username and password
+const char* mqttUser = "esp8266";
+const char* mqttPassword = "esp8266";
+
+// DHT sensor pin
 const int dhtPin = D4;
 
-// Replace with your device name
+// Device name
 const char* deviceName = "s1-gwb";
 
 // Initialize the DHT sensor
@@ -24,6 +28,7 @@ DHT dht(dhtPin, DHT22);
 
 // Function declaration
 void setupWiFi();
+void connectToMQTT();
 void sendSensorData(float temperature, float humidity, unsigned long timestamp, const char* device);
 void sendBufferedData();
 
@@ -41,12 +46,17 @@ int bufferIndex = 0;
 unsigned long previousTimestamp = 0;
 const unsigned long interval = 30000;
 
+WiFiClient espClient;
+PubSubClient client(espClient);
+
 void setup() {
     Serial.begin(9600);
 
     setupWiFi();
 
     dht.begin();
+
+    client.setServer(mqttServer, mqttPort);
 }
 
 void loop() {
@@ -86,6 +96,12 @@ void loop() {
 
         previousTimestamp = currentTimestamp;
     }
+
+    if (!client.connected()) {
+        connectToMQTT();
+    }
+
+    client.loop();
 }
 
 void setupWiFi() {
@@ -110,37 +126,27 @@ void setupWiFi() {
 }
 
 void sendSensorData(float temperature, float humidity, unsigned long age, const char* device) {
-    String url = "/upload";
+    char topic[50];
+    snprintf(topic, sizeof(topic), "sensor/%s", device);
+    char payload[100];
+    snprintf(payload, sizeof(payload), "{\"temperature\":%.2f,\"humidity\":%.2f,\"age\":%lu}", temperature, humidity, millis() - age);
+    client.publish(topic, payload);
+    Serial.println("Sent sensor data to MQTT broker!");
+}
 
-    WiFiClientSecure client;
-    client.setInsecure();  // skip verification
+void connectToMQTT() {
+    while (!client.connected()) {
+        Serial.print("Connecting to MQTT broker...");
 
-    if (!client.connect(serverAddress, serverPort)) {
-        Serial.println("Failed to connect to server!");
-        return;
-    }
-
-    // Calculate the length of the payload
-    String payload = "temp=" + String(temperature) + "&humidity=" + String(humidity) + "&age=" + String(millis() - age) + "&device=" + device;
-    int payloadLength = payload.length();
-
-    client.print("POST " + url + " HTTP/1.1\r\n" +
-                 "Host: " + String(serverAddress) + "\r\n" +
-                 "Connection: close\r\n" +
-                 "Content-Type: application/x-www-form-urlencoded\r\n" +
-                 "Content-Length: " + String(payloadLength) + "\r\n\r\n" +
-                 payload);
-
-    while (client.connected()) {
-        if (client.available()) {
-            String line = client.readStringUntil('\n');
-            Serial.println(line);
+        if (client.connect("ESP8266Client", mqttUser, mqttPassword)) {
+            Serial.println("connected");
+        } else {
+            Serial.print("failed, rc=");
+            Serial.print(client.state());
+            Serial.println(" retrying in 5 seconds");
+            delay(5000);
         }
     }
-
-    Serial.println("Sent sensor data to server!");
-
-    client.stop();
 }
 
 void sendBufferedData() {