实现STM32单片机的各种功能，包括USART通信，pwm波的输出，及输入捕获，及SPI数据通信，I2C的FLASH数据读取。-STM32 microcontroller to achieve a variety of functions, including USART communications, pwm wave output, and input capture, and data communications SPI, I2C the FLASH data read.