 }
 
 // read BME280 sensor data
-byte readBMESensor() {
+int readBMESensor() {
   double currentTemperature = 0;
   digitalWrite(led, HIGH);
   currentTemperature = bme.readTemperature();

Phant phant(server, publicKey, privateKey);

// interval counters for measurement and post
const int MEASUREMENT_RATE = 15000; // read sensor data every 30 sec
const int POST_RATE = 15 * 60000; // post data every 15 minutes
elapsedMillis lastMeasurement;
elapsedMillis lastPost;

    // read sensor data
    if (lastMeasurement > MEASUREMENT_RATE) {
      int bmeSensorStatus = readBMESensor();
      delay(200);
      int soil1SensorStatus = readSoilSensor(soilSensor1, soil1);

      // calc overall sensor status
      sensorStatus = bmeSensorStatus; // TODO
