// This example shows how to connect HTU21D to Cayenne using an ESP8266 and send/receive sample data. // Make sure you install the ESP8266 Board Package via the Arduino IDE Board Manager and select the correct ESP8266 board before compiling. //#define CAYENNE_DEBUG #define CAYENNE_PRINT Serial #include #include #include "Adafruit_HTU21DF.h" Adafruit_HTU21DF htu = Adafruit_HTU21DF(); // WiFi network info. char ssid[] = "ssid"; char wifiPassword[] = "wifiPassword"; // Cayenne authentication info. This should be obtained from the Cayenne Dashboard. char username[] = "MQTT_USERNAME"; char password[] = "MQTT_PASSWORD"; char clientID[] = "CLIENT_ID"; unsigned long lastMillis = 0; void setup() { Serial.begin(9600); Cayenne.begin(username, password, clientID, ssid, wifiPassword); Wire.begin(4, 5); // SDA, SCL htu.begin(); } void loop() { Cayenne.loop(); //Publish data every 1 seconds (1000 milliseconds). Change this value to publish at a different interval. if (millis() - lastMillis > 1000) { lastMillis = millis(); //Write data to Cayenne here. This example just sends the current uptime in milliseconds. Cayenne.virtualWrite(0, lastMillis); Cayenne.celsiusWrite(1, htu.readTemperature()); Cayenne.virtualWrite(2, htu.readHumidity(), "rel_hum", "p"); } } //Default function for processing actuator commands from the Cayenne Dashboard. //You can also use functions for specific channels, e.g CAYENNE_IN(1) for channel 1 commands. CAYENNE_IN_DEFAULT() { CAYENNE_LOG("CAYENNE_IN_DEFAULT(%u) - %s, %s", request.channel, getValue.getId(), getValue.asString()); //Process message here. If there is an error set an error message using getValue.setError(), e.g getValue.setError("Error message"); }