STM32 里面包含各种实验程序，LCD，LED，FLASH，PWM，24C02,WDOG等等，各种程序应有尽有-STM32 contains a variety of experimental procedures, LCD, LED, FLASH, PWM, 24 our fleet, WDOG, etc., all kinds of programs

PWM控制输出并通过LED显示PWM值并据有电压电流保护报警输出功能-PWM control output and PWM LED display value and according to a voltage-current protection alarm output function

PWM输出实验 延时函数初始化 串口初始化为115200 LED端口初始化 不分频。PWM频率=72000000/900=80Khz