利用一个I/O口，接一个按键，实现3功能操作：单击 + 双击 + 长按+特别操作，利用USART输出显示在串口助手。压缩文件里有详细说明。完整工程，打开即可使用。-Use an I/O port, then a key to achieve three functions: Click+ double+ long press+ special operations. Compressed files are described in detail.

STM32F030采用ARM Cortex内核，运算速度高达48 MHz。STM32F030是STM32系列中价格最低的产品，具有全套外设，例如高速12位ADC、先进且灵活的定时器、日历RTC和通信接口（例如 I2C、USART和SPI）。(STM32F030 adopts the ARM Cortex kernel, and the operation speed is as high as 48 MHz.STM32F030 is the lowest priced product in th