JaimeGomezGarcia/termostato

A Wemos D1 Mini temperature and humidity sensor

Relevant parts of this code

Each device gets its unique name from its chip Id

chipId = ESP.getChipId();
nombreNodo = tipoNodo + chipId;

The devide creates an MQTT topic tu publish its information. First we define some relevant strings that will be used as bricks to create the final topics.

const String mqttBase     = "casa/";
const String mqttType = "/sensor/";
const String mqttMon  = "/monitor/";
const String mqttTemp = "temperatura/";
const String mqttHum  = "humedad/";

Then we create some strings to store the final topics.

String mqttTempThisChip;
String mqttHumThisChip;
String mqttTempThisChipStatus;
String mqttHumThisChipStatus;

Then we build the final topics that will be specific for this device.

String mqttBaseThisChip = mqttBase + chipId;
String mqttBaseThisChipType = mqttBaseThisChip + mqttType;
mqttTempThisChip = mqttBaseThisChipType + mqttTemp;
mqttHumThisChip = mqttBaseThisChipType + mqttHum;
mqttTempThisChipStatus = mqttTempThisChip + "status/";
mqttHumThisChipStatus = mqttHumThisChip + "status/";

Every minute the device publishes its temperature reads on its mqtt topic.

if (currentMillis - previousMillis >= DELAY_MS)
  {
    // save the last time we entered here
    previousMillis = currentMillis;

    hum = dht.getHumidity();
    temp = dht.getTemperature();
    status = dht.getStatusString();
    
    if (client.isConnected())
    {
      client.publish(mqttTempThisChipStatus, status);
      if ( status == "OK")
      {
        client.publish(mqttTempThisChip, String(temp));
        client.publish(mqttHumThisChip, String(hum));
      }
    }
  }