WS2812-Neopixel library for Renesas RA controller. See the file WS2812.h in src folder of project. This neopixel library can be ported to any microcontroller if you have little bit knowledge of clock cycle of mcu and regiter level programming.
This library is inspired by http://www.friendlywire.com/tutorials/ws2812/ Please check his website for detail description of the library and how it works.