Sample Code for Wemos D1 Mini + MQTT (LED hint)

wemos-mqtt-leds.ino

//create a method to control the LED's

void ctrlLEDs(String topic, byte receivedChar){
  if (topic == "ledStatus/red"){ //every LED has it's own topic for individual control
    if(receivedChar == '1'){
      digitalWrite(redLED, HIGH);
    }
    else if (receivedChar == '0'){
      digitalWrite(redLED, LOW);
    }
    else{
      analogWrite(redLED, int(receivedChar));
    }
  }
  if (topic == "ledStatus/yellow"){
    if(receivedChar == '1'){
      digitalWrite(yellowLED, HIGH);
    }
    else if (receivedChar == '0'){
      digitalWrite(yellowLED, LOW);
    }
    else{
      analogWrite(yellowLED, int(receivedChar));
    }
  }
  //... finish this method for the Green and White LED's
  // There may be a better & shorter way of doing this!
}

//inside the callback() method, be sure to call the ctrlLEDs() method
ctrlLEDs(topic,msg);

//inside the reconnect() method, be sure to subscribe to all of the LED topics
client.subscribe("ledStatus/red");
client.subscribe("ledStatus/yellow");
client.subscribe("ledStatus/green");
client.subscribe("ledStatus/white");