For this one, I make a simple dashboard to push the message to MQTT server. In the stand-mode, the LCD shows the Clock.
Here is the schematics of this terminal:
The branded WEMOS ESP8266 is pleasant to work with. You only need a micro USB, press the upload button on Arduino IDE flash the chip. The code is here (GitHub). Change the topic to match the subscriber's one.:
Take a look at the highlight on the code (screenshot). That is the topic the dashboard pushes the message to, and our LEDs is waiting to see any news from the JSON message.
To publish a message, push the switch to turn the green led on (and red off), then slide up the pin and adjust, and finally push the button again to push the message onto MQTT server. The dashboard could publish a JSON message to 4 channels.
That is about it. I hope the tutorial is helpful.