超声波 测距 程序

用jsn超声波模块测距程序， 输出捕获时间 计算距离

JSN_TEST
user
startup
Obj
List
FWlib
4channelPWM.map
4channelPWM.uvgui.Administrator
4channelPWM.uvgui_Administrator.bak
4channelPWM.uvopt
4channelPWM.uvproj
4channelPWM_PWM.dep
4channelPWM_Target 1.dep
4channelPWM_uvopt.bak
4channelPWM_uvproj.bak
core_cm3.crf
core_cm3.d
core_cm3.o
main.d
misc.d
Nu_Link_Driver.ini
PWM.BAT
readme.txt
startup_stm32f10x_md.d
startup_stm32f10x_md.lst
startup_stm32f10x_md.o
stm32f10x_exti.d
stm32f10x_gpio.d
stm32f10x_it.d
stm32f10x_rcc.d
stm32f10x_tim.d
system_stm32f10x.crf
system_stm32f10x.d
system_stm32f10x.o
tim.d