MQTT controlled RGB led on NodeMCU

What is this?

This is a sample project enabling the control of a NodeMCU with a RGB led using MQTT.

It uses:

NodeMCU DevKit v1.0 based on ESP8266 microcontroller
RGB led with common cathode connected to GND and RGB anodes connected to pins 7,6,5 through 100 ohm resistors
Custom Lua firmware (online build, API Reference) including the following modules:
pwm: to control RGB led
mqtt: to publish and subscribe to MQTT topics
enduser_setup: to simplify initial WiFi configuration using a temporary access point and web server
CloudMQTT as MQTT broker (mosquitto can be used too)
Node-Red, an open-source web-based flow processing tool to trigger outputs based on inputs

Get started with ESPlorer.
Connect common cathode of RGB LED to GND and R,G,B anodes to pins 7,6,5 through 100 ohm resistors.
Set up a MQTT broker, for instance using CloudMQTT. Update server, user and password in mqtt_rgb.lua.
Flash lua files.
After first boot, a WiFi Access Point named "SetupGadget..." is created. Connect to it (you will get an IPv4 address through DHCP) and browse http://192.168.4.1 to configure the WiFi SSID and password to be used subsequently.
The on-board LED blinks once every second when not connected and once every 10 seconds once connected.
Use any MQTT client such as CloudMQTT web console to publish messages.
topic node/led controls on-board LED using payloads:
on
off
toggle
topic node/rgb controls RGB LED on pins 7,6,5 using payloads:
cycle starts and endless colour cycle
stop stops cycle
on turns white (you should stop cycle first)
off turns off (you should stop cycle first)
You can install Node-Red and import the flow to trigger actions based on events