【蓝桥杯嵌入式】13届程序题刷题记录及反思

 一、题目分析

考察内容：

• led
• 按键（短按）
• PWM输出（PA1）
• 串口接收
• lcd显示

根据PWM输出占空比调节，高频与低频切换

串口接收（指令解析）【中断接收】

2个显示界面

led灯闪烁定时器

二、Usr.c

/* Includes ------------------------------------------------------------------*/
#include "usr.h"
#include "usart.h"
/* values --------------------------------------------------------------------*/
struct keys key[4]={0,0,0,0};
uint8_t menu = 0;
uint8_t password_valid = 0;//密码有效信号
uint8_t password_err_3 = 0;//密码3次及以上输入错误信号
uint8_t password_err_time = 0;//密码3次及以上输入错误次数
uint8_t B1 = '@';
uint8_t B2 = '@';
uint8_t B3 = '@';
uint16_t F = 1000;
uint16_t D = 50;
uint16_t password = 123;//密码
/* define --------------------------------------------------------------------*/
#define MENU_PSD 0
#define MENU_STA 1

/*----------------------------------------------------------------------------*/
void led_set(uint8_t led_dis)
{
    HAL_GPIO_WritePin(GPIOC,GPIO_PIN_All,GPIO_PIN_SET);//关闭所有led
    HAL_GPIO_WritePin(GPIOC,led_dis<<8,GPIO_PIN_RESET);
    HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_SET);
    HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_RESET);
}
void led_2_toggle(void){
    HAL_GPIO_WritePin(GPIOC,GPIO_PIN_8,GPIO_PIN_SET);
    HAL_GPIO_WritePin(GPIOC,GPIO_PIN_10,GPIO_PIN_SET);
    HAL_GPIO_WritePin(GPIOC,GPIO_PIN_11,GPIO_PIN_SET);
    HAL_GPIO_WritePin(GPIOC,GPIO_PIN_12,GPIO_PIN_SET);
    HAL_GPIO_WritePin(GPIOC,GPIO_PIN_13,GPIO_PIN_SET);
    HAL_GPIO_WritePin(GPIOC,GPIO_PIN_14,GPIO_PIN_SET);
    HAL_GPIO_WritePin(GPIOC,GPIO_PIN_15,GPIO_PIN_SET);
    HAL_GPIO_TogglePin(GPIOC,GPIO_PIN_9);
    HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_SET);
    HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_RESET);
}

//key_control
void key_control(void)
{
    if(key[0].single_flag == 1){
        key[0].single_flag = 0;
        //仅在PSD有效
        if(menu == MENU_PSD){
            if(B1 == '@'){
                B1 = '0';
            }else{
                B1++;
                if(B1>'9'){
                    B1 = '0';
                }
            }
        }
    }else if(key[1].single_flag == 1){
        key[1].single_flag = 0;
        if(menu == MENU_PSD){
            if(B2 == '@'){
                B2 = '0';
            }else{
                B2++;
                if(B2>'9'){
                    B2 = '0';
                }
            }
        }

    }else if(key[2].single_flag == 1){
        key[2].single_flag = 0;
        if(menu == MENU_PSD){
            if(B3 == '@'){
                B3 = '0';
            }else{
                B3++;
                if(B3>'9'){
                    B3 = '0';
                }
            }
        }  

    }else if(key[3].single_flag == 1){       //密码输入完成确认
        key[3].single_flag = 0;
        //此处要写密码判断
        if((B1-'0')*100+(B2-'0')*10+(B3-'0') == password){
            password_valid = 1;
        }else{
            password_err_time ++;
        }
        if(password_valid == 1){
            menu = MENU_STA;
            password_err_3 = 0;
            password_err_time = 0;//输入成功将err次数清0
        }else{
            B1 ='@';
            B2 ='@';
            B3 ='@';
            if(password_err_time >= 3){
                password_err_3 = 1;
            }
        }
    }else{
        key[0].long_flag = 0;
        key[1].long_flag = 0;
        key[2].long_flag = 0;
        key[3].long_flag = 0;
    }
}
void dispaly_init(void){
    LCD_Clear(Black);
    LCD_SetBackColor(Black);
    LCD_SetTextColor(White);
}
void menu_display(void)
{
    char text[30]={NULL};
    if(menu == MENU_PSD){
        sprintf(text,"       PSD           ");
        LCD_DisplayStringLine(Line1,(u8*)text);
        sprintf(text,"    B1:%c     ",B1);
        LCD_DisplayStringLine(Line3,(u8*)text);
        sprintf(text,"    B2:%c     ",B2);
        LCD_DisplayStringLine(Line4,(u8*)text);
        sprintf(text,"    B3:%c     ",B3);
        LCD_DisplayStringLine(Line5,(u8*)text);
        
    }else{
        fre_2hz_duty_10_set();
        sprintf(text,"       STA           ");
        LCD_DisplayStringLine(Line1,(u8*)text);
        sprintf(text,"    F:%d",F);
        LCD_DisplayStringLine(Line3,(u8*)text);
        sprintf(text,"    D:%d",D);
        LCD_DisplayStringLine(Line4,(u8*)text);
        LCD_ClearLine(Line5);
    }
}

//2hz
void fre_2hz_duty_10_set(void)
{
    F= 2000;
    D =10;
    __HAL_TIM_SetCompare(&htim2,TIM_CHANNEL_2,100-1);//占空比百分之10
    __HAL_TIM_SET_PRESCALER(&htim2,40-1);//2hz
}
//1hz 50%
void fre_1hz_duty_50_set(void){
    __HAL_TIM_SetCompare(&htim2,TIM_CHANNEL_2,500-1);//占空比百分之50
    __HAL_TIM_SET_PRESCALER(&htim2,80-1);//1hz
    F= 2000;
    D = 50;
}

//定时器中断服务函数
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
    if(htim->Instance == TIM6)
    {
        key[0].key_sta = HAL_GPIO_ReadPin(B1_Port,B1_Pin);
        key[1].key_sta = HAL_GPIO_ReadPin(B2_Port,B2_Pin);
        key[2].key_sta = HAL_GPIO_ReadPin(B3_Port,B3_Pin);
        key[3].key_sta = HAL_GPIO_ReadPin(B4_Port,B4_Pin);
        for(uint8_t i =0;i<4;i++){
            switch(key[i].judge_sta){
                case 0:{
                    if(key[i].key_sta == 0){
                        key[i].judge_sta = 1;
                        key[i].key_time = 0;
                    }else {
                        key[i].judge_sta = 0;
                    }
                }break;
                case 1:{
                    if(key[i].key_sta == 0){
                        key[i].judge_sta = 2;
                    }else{
                        key[i].judge_sta = 0;
                    }
                    
                }break;
                case 2:{
                    if(key[i].key_sta == 1){
                        if(key[i].key_time< Short_time){
                            key[i].single_flag = 1;
                            key[i].judge_sta = 0;
                        }
                    }else{
                        key[i].key_time++;
                        if(key[i].key_time > Long_time){
                            key[i].long_flag = 1;
                            key[i].judge_sta = 0;
                        }
                    }
                }break;
            }
        }
    }
    if(htim->Instance == TIM7){
        static uint16_t time = 0;
        if(password_valid == 1){
            password_err_3 = 0;
            led_set(0x01);
             F= 2000;
             fre_2hz_duty_10_set();
            if(time>= 50-1){
                password_valid = 0;
                led_set(0x00);
                time = 0;
                menu = MENU_PSD;
                B1 = '@';
                B2 = '@';
                B3 = '@';
            }else{
                time ++;
            }
        }else if(password_err_3 == 1){
            static uint8_t cnt = 0;
            cnt ++;
            cnt %= 2;
            //led2翻转
            if(cnt == 0){
                led_set(0x02);
            }else{
                led_set(0x00);
            }
            //5s后接触报警
            if(time>= 50-1){
                password_err_3 = 0;
                led_set(0x00);
                time = 0;  //5s计时清零
                cnt = 0;
            }else{
                time ++;   //计时++
            }
            F= 1000;
            fre_1hz_duty_50_set();//方波1hz
        }else{
            time = 0;
            fre_1hz_duty_50_set();//方波1hz
        }                     
    }
    
}

//串口接收完成中断回调服务函数
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
    if(huart->Instance == USART1)
    {
        led_set(0xaa);
        if(((recevie[0]-'0')*100+(recevie[1]-'0')*10+(recevie[2]-'0') == password)&&(recevie[3]) == '-'){
            password = (recevie[4]-'0')*100+(recevie[5]-'0')*10+(recevie[6]-'0');
        }
        HAL_UART_Receive_IT(&huart1,recevie,7);
    }
}

三、Usr.h

#ifndef __USR_H__
#define __USR_H__

#ifdef __cplusplus
extern "C" {
#endif

/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "lcd.h"
#include "stdio.h"
#include "tim.h"
/* extern --------------------------------------------------------------------*/
extern uint8_t recevie[7];
//key    
struct keys{
    uint8_t judge_sta;
    uint8_t key_sta;
    uint8_t single_flag;
    uint8_t long_flag;
    uint8_t key_time;
};
/*key define-------------------------------------------------------------------*/   
#define B1_Port GPIOB
#define B2_Port GPIOB
#define B3_Port GPIOB  
#define B4_Port GPIOA

#define B1_Pin  GPIO_PIN_0
#define B2_Pin  GPIO_PIN_1
#define B3_Pin  GPIO_PIN_2   
#define B4_Pin  GPIO_PIN_0

#define Long_time  200   //2s
#define Short_time 50    //0.5s

//led
void led_set(uint8_t led_dis);

void led_2_toggle(void);
//key_control
void key_control(void);
void dispaly_init(void);
void menu_display(void);
void fre_2hz_duty_10_set(void);
    
  
    

#ifdef __cplusplus
}
#endif
#endif 

四、串口中断接收

本题目要求接收7个ASCII码字符

定义uint8_t 类型接收数组

uint8_t recevie[7];

在while(1)前开启串口接收中断函数，接收7个字符后进入中断服务函数

HAL_UART_Receive_IT(&huart1,recevie,7);

 根据中断类型，调用中断回调函数

下面展示中断服务函数

//串口接收完成中断回调服务函数
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
    if(huart->Instance == USART1)
    {
        led_set(0xaa);
        if(((recevie[0]-'0')*100+(recevie[1]-'0')*10+(recevie[2]-'0') == password)&&(recevie[3]) == '-'){
            password = (recevie[4]-'0')*100+(recevie[5]-'0')*10+(recevie[6]-'0');
        }
        HAL_UART_Receive_IT(&huart1,recevie,7);
    }
}

五、LED灯闪烁问题

计时应该是正确的5s

    if(htim->Instance == TIM7){
        static uint16_t time = 0;
        if(password_valid == 1){
            password_err_3 = 0;
            led_set(0x01);
             F= 2000;
             fre_2hz_duty_10_set();
            if(time>= 50-1){
                password_valid = 0;
                led_set(0x00);
                time = 0;
                menu = MENU_PSD;
                B1 = '@';
                B2 = '@';
                B3 = '@';
            }else{
                time ++;
            }
        }else if(password_err_3 == 1){
            static uint8_t cnt = 0;
            cnt ++;
            cnt %= 2;
            //led2翻转
            if(cnt == 0){
                led_set(0x02);
            }else{
                led_set(0x00);
            }
            //5s后接触报警
            if(time>= 50-1){
                password_err_3 = 0;
                led_set(0x00);
                time = 0;  //5s计时清零
                cnt = 0;
            }else{
                time ++;   //计时++
            }
            F= 1000;
            fre_1hz_duty_50_set();//方波1hz
        }else{
            time = 0;
            fre_1hz_duty_50_set();//方波1hz
        }                     
    }

六、 总结

本次只写一个usr.c usr.h，发现确实方便了许多！！相较于14届难度较小

比照LCD的cubemx配置引脚的时候，记得配置PD2（led锁存器引脚）

复制其他.h时后记得更改预编译

#ifndef __USR_H__        //记得更改
#define __USR_H__

#ifdef __cplusplus
extern "C" {
#endif

/* Includes ------------------------------------------------------------------*/
#include "main.h"
   

#ifdef __cplusplus
}
#endif
#endif 

如果没有改为__USR_H__,跳转函数跳转不进去usr.c文件，会显示C99_warning