Preparing Arduino IDE

Download

Download the newest version of Arduino IDE from here and install it.

Adding the ESP8266 to your boards

1. Go to File -> Preferences and add http://arduino.esp8266.com/stable/package_esp8266com_index.json to the Additional Boards Manager URLs. You can add multiple URLs, separating them with commas.

2. Go to Tools -> Board -> Boards Manager...

3. Type ESP8266 into the search
4. Select esp8266 by ESP8266 Community and click Install

Adding the required libraries

General

You can add libraries by going to Sketch -> Include Library and then choose Manage Libraries... or Add .ZIP Library.... This depends on the library you want to download.

ESPAsyncWebServer

Download the library here and add it by using Add .ZIP Library...

ESPAsyncTCP

Download the library here and add it by using Add .ZIP Library...

Timezone

Just use Manage Libraries..., search for Timezone and install it.

Timer

Download the library here and add it by using Add .ZIP Library...

Time

Download the library here and add it by using Add .ZIP Library...

PubSubClient

Just use Manage Libraries..., search for PubSubClient and install it.

FastLED

Just use Manage Libraries..., search for FastLED and install it.

Adding SPIFFS support

In order to upload the webserver files you need to add the SPIFFS support.

1. Download the tool here
2. In your Arduino sketchbook directory, create tools directory if it doesn’t exist yet
3. Unpack the tool into tools directory (the path will look like <home_dir>/Arduino/tools/ESP8266FS/tool/esp8266fs.jar)
4. Restart Arduino IDE and check the Tools menu for ESP8266 Sketch Data Upload

Loading the right settings

Open the Tools menu and set everything like shown below