The STM32 DC fan can adjust the speed by pressing PWM and the parameters are displayed on the LCD.

I still remember that after I finished learning STM32, I felt like I knew nothing, and basically relied on the knowledge of microcontrollers to get through the final test. Then, I actually always wanted to learn STM32 well, but I felt that learning too much was not a good thing. I always felt that it was not a bad thing to learn a lot, but I always felt that there should be one skill that you are very outstanding in among the skills you have learned.

//
//Design: DC motor speed regulation, change the duty cycle by pressing buttons to achieve the purpose of speed regulation, and display various parameters at the same time
//Author: Touch
//Time :2017.6.5
//
#include "led.h"
#include "delay.h"
#include "sys.h"
#include "usart.h
" #include "lcd.h"
#include "key.h"
#include "pwm.h"
 int main(void)
 { 
 
 unsigned int duty_cycle=0; 
 unsigned int k=0; 
 u8 t=0;  
       u16 led0pwmval=0;   
 u8 dir=1; 
 delay_init(); //Delay function initializationuart_init  
 (9600); //Serial port initialized to 9600
 LED_Init(); //Initialize the hardware interface connected to the LED
  LCD_Init(); 
 KEY_Init(); 
       TIM1_PWM_Init(899,0); //No frequency division. PWM frequency = 72000 / (899 + 1) = 80Khz
 
 POINT_COLOR = RED; // Set the font to red
// Fixed display area
 LCD_ShowString (70, 20, 200, 16, 16,"DC_Motor Project");
 LCD_ShowString (20, 50, 200, 16, 16,"Author: TH ZJW LZH");
 LCD_ShowString (20, 70, 200, 16, 16,"Teacher: LD"); 
 LCD_ShowString (20, 130, 200, 16, 16,"Menu:"); LCD_ShowString (20, 150, 200, 16, 16
 ,"Max_Vaule"); LCD_ShowString (
       160, 150, 200, 16, 16,"900");
 LCD_ShowString(20,170,200,16,16,"Down_Mode");
 LCD_ShowString(20,190,200,16,16,"Up_Mode");
 LCD_ShowString(20,210,200,16,16,"Stop_Mode"); //Resolution 320*240
 
 LCD_ShowString(20,230,200 ,16,16,"Duty_cycle");
 LCD_ShowString(180,230,200,16,16,"%");
 LCD_ShowString(20,250,200,16,16,"Air_Grade");
 
       LCD_ShowString(90,300,200,16,16,"2017/6/5");

 
    while(1)
 { 
  LCD_ShowxNum(150,210,led0pwmval,4,16,0);     //计数值
  duty_cycle=led0pwmval/9;                     //占空比定义
  if(led0pwmval==50)   duty_cycle=5;
  if(led0pwmval==100)  duty_cycle=9;
  if(led0pwmval==900)  duty_cycle=99;
  LCD_ShowxNum(160,230,duty_cycle,2,16,0);
  
     if(duty_cycle>=0 &&duty_cycle<33)    k=1;
     if(duty_cycle>=33&&duty_cycle<66)    k=2;
           if(duty_cycle>=66&&duty_cycle<99)    k=3;
  
     switch(k)
        {
   case 1:LCD_ShowString(160,250,200,16,16,"Little");break;
        case 2:LCD_ShowString(160,250,200,16,16,"Middle");break;
  case 3:LCD_ShowString(160,250,200,16,16,"Heavy");break;
  default:LCD_ShowString(160,250,200,16,16,"Little");break;
        } 
  
  
  
  
  t=KEY_Scan(0);                  //得到键值
     switch(t)
     {      
   case KEY0_PRES:      //1
    {
    LED0=!LED0;
//PWM
        led0pwmval=led0pwmval-50;       
     if(led0pwmval>5000)
     {
     led0pwmval=0;  
     }
              TIM_SetCompare1(TIM1,led0pwmval);
    delay_ms(60);
//显示 
     }
    break;  
   case KEY1_PRES:     //2   
    {
          LED1=!LED1;
    delay_ms(10); 
    led0pwmval=led0pwmval+50;
    if(led0pwmval>850)
     {
     led0pwmval=899;                             
     }
    TIM_SetCompare1(TIM1,led0pwmval); 
    delay_ms(60);  
    }
    break;    
   case WKUP_PRES:      //3 
   {    
    LED0=!LED0;
    LED1=!LED1;
//PWM
         led0pwmval=0;
    TIM_SetCompare1(TIM1,led0pwmval); 
//显示                       
   }    
    break;
   default:
    delay_ms(10); 
                            break;        
           }
       }
}