Control WS2812 by using sTM32f4 discovery

STM32F4开发板，同时控制电机和灯带联动，电机不动时灯带处于单色变换模式rainbow模式，电机运动时灯带处于多色流水状态rainbowcycle模式；(STM32F4 development board, at the same time control the motor and light band linkage, when the motor is not moving, the light belt is in the monochromatic mode rainbow mod

采用spi模拟ws2812时序，stm32F4采用dma传送数据，库文件为stm32标准库(SPI is used to simulate ws2812 timing, stm32F4 uses DMA to transmit data, and the library file is STM32 standard library.)

ws2812 stm32f4的驱动程序，可轻松实现对ws2812的驱动(Ws2812 stm32f4 driver)