ESP32 – Favoriot Example using MQTT and Wifi
September 14th, 2026 Posted by favoriotadmin HOW-TO, Internet of Things, IOT PLATFORM 0 thoughts on “ESP32 – Favoriot Example using MQTT and Wifi”Here’s an example of the source code:
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/*
* ESP32 -> Favoriot MQTT Example
* ------------------------------
* - Connects to Wi-Fi
* - Connects to Favoriot MQTT broker (non‑secure port 1883)
* - Publishes a JSON payload to {access_token}/v2/streams
* - Subscribes to {access_token}/v2/streams/status
* - Reconnects automatically if connection drops
* - Non‑blocking loop (no delay())
*/
#include <WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h> // for easier JSON building
// ================== Wi‑Fi Credentials ==================
const char* WIFI_SSID = "YOUR_WIFI_SSID";
const char* WIFI_PASSWORD = "YOUR_WIFI_PASSWORD";
// ================== Favoriot Credentials ==================
const char* DEVICE_DEVELOPER_ID = "deviceDefault@your_username"; // e.g., deviceDefault@favoriot
const char* ACCESS_TOKEN = "your_device_access_token"; // from Favoriot platform
// ================== MQTT Broker Configuration ==================
const char* MQTT_HOST = "mqtt.favoriot.com";
const int MQTT_PORT = 1883; // 1883 = plain TCP, 8883 = TLS (secure)
// For TLS, you would need additional certificates and use WiFiClientSecure – see notes below.
WiFiClient espClient;
PubSubClient client(espClient);
// Topics
const String PUBLISH_TOPIC = String(ACCESS_TOKEN) + "/v2/streams"; // publish data
const String SUBSCRIBE_TOPIC = String(ACCESS_TOKEN) + "/v2/streams/status"; // receive status
// ================== Timing ==================
const unsigned long PUBLISH_INTERVAL = 10000; // publish every 10 seconds
unsigned long lastPublishTime = 0;
// ------------------------------------------------------------------
// Connect to Wi‑Fi
// ------------------------------------------------------------------
void setupWiFi() {
Serial.print("Connecting to Wi‑Fi");
WiFi.mode(WIFI_STA);
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("\n✅ Connected to Wi‑Fi. IP: " + WiFi.localIP().toString());
}
// ------------------------------------------------------------------
// Reconnect to MQTT broker (called when connection lost)
// ------------------------------------------------------------------
void reconnectMQTT() {
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Use access token as username AND password
if (client.connect("ESP32Client", ACCESS_TOKEN, ACCESS_TOKEN)) {
Serial.println("✅ Connected to MQTT");
// Resubscribe to status topic
client.subscribe(SUBSCRIBE_TOPIC.c_str());
} else {
Serial.print("❌ Failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
delay(5000); // Wait 5s before retrying
}
}
}
// ------------------------------------------------------------------
// Callback for subscription (status messages)
// ------------------------------------------------------------------
void callback(char* topic, byte* payload, unsigned int length) {
Serial.print("Message arrived on topic: ");
Serial.println(topic);
Serial.print("Payload: ");
for (int i = 0; i < length; i++) {
Serial.print((char)payload[i]);
}
Serial.println();
}
// ------------------------------------------------------------------
// Build JSON payload and publish
// ------------------------------------------------------------------
void publishData() {
// Use ArduinoJson to create the payload
StaticJsonDocument<256> jsonDoc;
jsonDoc["device_developer_id"] = DEVICE_DEVELOPER_ID;
// Replace this with actual sensor reads (e.g., temperature, humidity, etc.)
JsonObject data = jsonDoc.createNestedObject("data");
data["temperature"] = 25.3; // example value
data["humidity"] = 60.1;
data["sensor_id"] = "esp32-01";
// Serialize to a char buffer
char buffer[256];
serializeJson(jsonDoc, buffer);
Serial.print("Publishing: ");
Serial.println(buffer);
// Publish to the topic
if (client.publish(PUBLISH_TOPIC.c_str(), buffer)) {
Serial.println("✅ Published successfully");
} else {
Serial.println("❌ Publish failed");
}
}
// ------------------------------------------------------------------
// Arduino setup
// ------------------------------------------------------------------
void setup() {
Serial.begin(115200);
setupWiFi();
// Configure MQTT
client.setServer(MQTT_HOST, MQTT_PORT);
client.setCallback(callback);
}
// ------------------------------------------------------------------
// Arduino loop (non‑blocking)
// ------------------------------------------------------------------
void loop() {
if (!client.connected()) {
reconnectMQTT();
}
client.loop(); // keep the MQTT connection alive
// Publish data at intervals
if (millis() - lastPublishTime >= PUBLISH_INTERVAL) {
publishData();
lastPublishTime = millis();
}
}
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<script data-wp-block-html="js">
/*
* ESP32 -> Favoriot MQTT Example
* ------------------------------
* - Connects to Wi-Fi
* - Connects to Favoriot MQTT broker (non‑secure port 1883)
* - Publishes a JSON payload to {access_token}/v2/streams
* - Subscribes to {access_token}/v2/streams/status
* - Reconnects automatically if connection drops
* - Non‑blocking loop (no delay())
*/
#include <WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h> // for easier JSON building
// ================== Wi‑Fi Credentials ==================
const char* WIFI_SSID = "YOUR_WIFI_SSID";
const char* WIFI_PASSWORD = "YOUR_WIFI_PASSWORD";
// ================== Favoriot Credentials ==================
const char* DEVICE_DEVELOPER_ID = "deviceDefault@your_username"; // e.g., deviceDefault@favoriot
const char* ACCESS_TOKEN = "your_device_access_token"; // from Favoriot platform
// ================== MQTT Broker Configuration ==================
const char* MQTT_HOST = "mqtt.favoriot.com";
const int MQTT_PORT = 1883; // 1883 = plain TCP, 8883 = TLS (secure)
// For TLS, you would need additional certificates and use WiFiClientSecure – see notes below.
WiFiClient espClient;
PubSubClient client(espClient);
// Topics
const String PUBLISH_TOPIC = String(ACCESS_TOKEN) + "/v2/streams"; // publish data
const String SUBSCRIBE_TOPIC = String(ACCESS_TOKEN) + "/v2/streams/status"; // receive status
// ================== Timing ==================
const unsigned long PUBLISH_INTERVAL = 10000; // publish every 10 seconds
unsigned long lastPublishTime = 0;
// ------------------------------------------------------------------
// Connect to Wi‑Fi
// ------------------------------------------------------------------
void setupWiFi() {
Serial.print("Connecting to Wi‑Fi");
WiFi.mode(WIFI_STA);
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("\n✅ Connected to Wi‑Fi. IP: " + WiFi.localIP().toString());
}
// ------------------------------------------------------------------
// Reconnect to MQTT broker (called when connection lost)
// ------------------------------------------------------------------
void reconnectMQTT() {
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Use access token as username AND password
if (client.connect("ESP32Client", ACCESS_TOKEN, ACCESS_TOKEN)) {
Serial.println("✅ Connected to MQTT");
// Resubscribe to status topic
client.subscribe(SUBSCRIBE_TOPIC.c_str());
} else {
Serial.print("❌ Failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
delay(5000); // Wait 5s before retrying
}
}
}
// ------------------------------------------------------------------
// Callback for subscription (status messages)
// ------------------------------------------------------------------
void callback(char* topic, byte* payload, unsigned int length) {
Serial.print("Message arrived on topic: ");
Serial.println(topic);
Serial.print("Payload: ");
for (int i = 0; i < length; i++) {
Serial.print((char)payload[i]);
}
Serial.println();
}
// ------------------------------------------------------------------
// Build JSON payload and publish
// ------------------------------------------------------------------
void publishData() {
// Use ArduinoJson to create the payload
StaticJsonDocument<256> jsonDoc;
jsonDoc["device_developer_id"] = DEVICE_DEVELOPER_ID;
// Replace this with actual sensor reads (e.g., temperature, humidity, etc.)
JsonObject data = jsonDoc.createNestedObject("data");
data["temperature"] = 25.3; // example value
data["humidity"] = 60.1;
data["sensor_id"] = "esp32-01";
// Serialize to a char buffer
char buffer[256];
serializeJson(jsonDoc, buffer);
Serial.print("Publishing: ");
Serial.println(buffer);
// Publish to the topic
if (client.publish(PUBLISH_TOPIC.c_str(), buffer)) {
Serial.println("✅ Published successfully");
} else {
Serial.println("❌ Publish failed");
}
}
// ------------------------------------------------------------------
// Arduino setup
// ------------------------------------------------------------------
void setup() {
Serial.begin(115200);
setupWiFi();
// Configure MQTT
client.setServer(MQTT_HOST, MQTT_PORT);
client.setCallback(callback);
}
// ------------------------------------------------------------------
// Arduino loop (non‑blocking)
// ------------------------------------------------------------------
void loop() {
if (!client.connected()) {
reconnectMQTT();
}
client.loop(); // keep the MQTT connection alive
// Publish data at intervals
if (millis() - lastPublishTime >= PUBLISH_INTERVAL) {
publishData();
lastPublishTime = millis();
}
}
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