对于无人机遥控器来说：周期为15ms，占空比7%为关闭     13%为最大
使用stm32f745的HAL库： 循环得到电调的周期和占空比： 周期从1ms开始到100ms     占空比从90%到10%（可继续分）     int main( ) {          int i,j;


         HAL_Init();
         SystemClock_Config();
         MX_GPIO_Init();
         MX_USART6_UART_Init();              while (1)
         {                 //PWM  PD12 
                   for(i=1;i<100;i++)
                   { 
                           
                            for(j=9;j>0;j--)
                            {
                                     TIM4_PWM_Init(i*1000-1,108-1);   //周期是n  ms
                                     TIM_SetTIM4Compare1(i*100*j);   
                           
                             printf("i=%d ",i);       
                                     printf("j=%d ",j);       
                                     HAL_Delay(5000);                                   
                            }
                   }
                          } }