用TIM3定时器在PA6、PA7、PB0、PB1输出四种频率相同占空比分别是50 、37.5 、25 、12.5 的信号。 用TIM2的PWM_Input功能，从PA1口捕获PWM信号的频率及占空比，并用USART1输出测量信息。-At TIM3 timer with PA6, PA7, PB0, PB1 output frequency of the same four are 50 duty cycle, respectively, 37.5 , 25 , 12.5 of the

基于STM32系列编写的二路对称PWM输出功能代码。-Two way symmetric PWM output function code based on the preparation of STM32 series.

STM32利用红外遥控pwm从而调节led亮度-STM32 using infrared remote control PWM to adjust the led brightness