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stm32-course/Examples/Timer_UltraSonic/Readme.md

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初始化版本
2 years ago
# 超声波测距 - 基本定时器方法
- 初始化外部晶振，配置SYSCLK与Timer Clock均为72MHz
- 配置GPIO
- PA11配置为Output，设置标签TRIG
- PA10配置为Input，设置标签ECHO
- TIM1配置
- Clock Source配置为Internal Clock
- Prescaler配置为720-1，即分频到周期10us
- Counter Period配置为最大值65535
- 将USART2配置为Asynchronous
- 测距流程
- 拉高TRIG，等待5ms再拉低，即触发模块输出
- 清零定时器的计数，等待ECHO引脚拉高
- ECHO拉高时启动定时器
- 待ECHO拉低时，停止定时器，并计算距离