Before starting to create an RGB controller from scratch, I’ve searched on Hackadays to see if anything similar had been done till then. I had found a $5 Wifi LED Dimmer w/ ESP8266 from Tom Clement and fork his GitHub project to get started with. It’s a one channel LED dimmer but is very close to the design I needed.
So many thanks to him as I hadn’t to search for the ESP and DC-DC converter footprint in eagle and I reuse part of his design.
The MOSFET and LED strip driving part was greatly inspire by Adafruit RGB LED Strip guide, so thanks Adafruit for their good guide!