蓝桥杯嵌入式第8届真题(完成) STM32G431

题目

分析和代码

对比第六届和第七届，这届的题目在逻辑思维上确实要麻烦不少，可以从题目看出，这届题目对时间顺序的要求很严格，所以就可以使用状态机的思想来编程，拿到类似题目不要急着写代码，一定要先分析好步骤，想出状态转换的逻辑后，在根据逻辑写代码写起来就很快了。

main.c

/* USER CODE BEGIN Header */
/********************************************************************************* @file           : main.c* @brief          : Main program body******************************************************************************* @attention** <h2><center>&copy; Copyright (c) 2021 STMicroelectronics.* All rights reserved.</center></h2>** This software component is licensed by ST under BSD 3-Clause license,* the "License"; You may not use this file except in compliance with the* License. You may obtain a copy of the License at:*                        opensource.org/licenses/BSD-3-Clause********************************************************************************/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "rtc.h"
#include "tim.h"
#include "gpio.h"/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "key.h"
#include "led.h"
#include "string.h"
#include "stdio.h"
/* USER CODE END Includes *//* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
extern struct Key key[4];//4个按键
uint8_t lcdtext[30]; //lcd显示的内容
uint8_t status[30]; //lcd显示的内容
uint8_t led;//LED状态
uint8_t setfloor[5]={0,0,0,0,0};//四层楼，为了方便1-4所以数组大小为5
uint32_t key_time_1s; //按键按下后等待的1s
uint32_t open_or_close_door_time_4s; //开门或者关门所需时间
uint32_t up_or_down_dir_time_6s; //电梯往上一楼或者往下一楼所需的时间
uint32_t wait_time_2s; //电梯在每层楼等待时间
uint8_t current_floor = 1;//当前所在层
RTC_DateTypeDef D; //用于显示日期
RTC_TimeTypeDef T; //用于显示时间
uint8_t process_status = 0;//执行的状态
uint8_t dir = 2;//是上还是下，默认停止
//下面用于流水灯的部分
uint32_t lastUpdateTime = 0; // 上次更新LED状态的时间
const uint32_t updateInterval = 200; // 更新间隔，以毫秒为单位
uint8_t flow_led_enable = 0;  //是否打开流水灯
/* USER CODE END PTD *//* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD *//* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM *//* USER CODE END PM *//* Private variables ---------------------------------------------------------*//* USER CODE BEGIN PV *//* USER CODE END PV *//* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
void led_process(void);
void key_process(void);
void lcd_process(void);
void status_process(void);/* USER CODE END PFP *//* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 *//* USER CODE END 0 *//*** @brief  The application entry point.* @retval int*/
int main(void)
{/* USER CODE BEGIN 1 *//* USER CODE END 1 *//* MCU Configuration--------------------------------------------------------*//* Reset of all peripherals, Initializes the Flash interface and the Systick. */HAL_Init();/* USER CODE BEGIN Init *//* USER CODE END Init *//* Configure the system clock */SystemClock_Config();/* USER CODE BEGIN SysInit *//* USER CODE END SysInit *//* Initialize all configured peripherals */MX_GPIO_Init();MX_TIM2_Init();MX_RTC_Init();MX_TIM16_Init();MX_TIM17_Init();/* USER CODE BEGIN 2 */HAL_TIM_Base_Start_IT(&htim2);LCD_Init();/* USER CODE END 2 *//* Infinite loop *//* USER CODE BEGIN WHILE */LCD_Clear(Black);LCD_SetBackColor(Black);LCD_SetTextColor(White);LED_display(0x00);sprintf((char *)lcdtext,"        %d",current_floor); //默认为1楼LCD_DisplayStringLine(Line3,lcdtext);while (1){led_process();lcd_process();key_process();status_process();/* USER CODE END WHILE *//* USER CODE BEGIN 3 */}/* USER CODE END 3 */
}/*** @brief System Clock Configuration* @retval None*/
void SystemClock_Config(void)
{RCC_OscInitTypeDef RCC_OscInitStruct = {0};RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};/** Configure the main internal regulator output voltage*/HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1);/** Initializes the RCC Oscillators according to the specified parameters* in the RCC_OscInitTypeDef structure.*/RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_LSI;RCC_OscInitStruct.HSIState = RCC_HSI_ON;RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;RCC_OscInitStruct.LSIState = RCC_LSI_ON;RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;RCC_OscInitStruct.PLL.PLLM = RCC_PLLM_DIV2;RCC_OscInitStruct.PLL.PLLN = 20;RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK){Error_Handler();}/** Initializes the CPU, AHB and APB buses clocks*/RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK){Error_Handler();}/** Initializes the peripherals clocks*/PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC;PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK){Error_Handler();}
}/* USER CODE BEGIN 4 */
void key_process(void)
{if((process_status==0||process_status==1))//没有按键按下时，和按键按下1s内还可以继续按{sprintf((char *)status,"    wait key      ");if(key[0].key_flag&&current_floor!=0+1) //不能是当前楼层{key[0].key_flag = 0;setfloor[1] = 1;//设置目标楼层led|=0x01; //设置对应led打开LED_display(led);//打开对应ledprocess_status = 1;//按键按下后进入1s等待状态key_time_1s = uwTick; //更新按键按下时时间}if(key[1].key_flag&&current_floor!=1+1){key[1].key_flag = 0;setfloor[2] = 1;led|=0x02;LED_display(led);process_status = 1;key_time_1s = uwTick;}if(key[2].key_flag&&current_floor!=2+1){key[2].key_flag = 0;setfloor[3] = 1;led|=0x04;LED_display(led);process_status = 1;key_time_1s = uwTick;}if(key[3].key_flag&&current_floor!=3+1){key[3].key_flag = 0;setfloor[4] = 1;led|=0x08;LED_display(led);process_status = 1;key_time_1s = uwTick;}}}void lcd_process(void)
{HAL_RTC_GetDate(&hrtc,&D,RTC_FORMAT_BIN);HAL_RTC_GetTime(&hrtc,&T,RTC_FORMAT_BIN);sprintf((char *)lcdtext,"      FLOOR");LCD_DisplayStringLine(Line1,lcdtext);
//	sprintf((char *)lcdtext,"        %d",current_floor);
//	LCD_DisplayStringLine(Line3,lcdtext);sprintf((char *)lcdtext,"     %02d:%02d:%02d",T.Hours,T.Minutes,T.Seconds);LCD_DisplayStringLine(Line4,lcdtext);//LCD_ClearLine(Line7);sprintf((char *)lcdtext,"%s",status);LCD_DisplayStringLine(Line7,lcdtext);sprintf((char *)lcdtext,"  floors:%d-%d-%d-%d",setfloor[1],setfloor[2],setfloor[3],setfloor[4]);LCD_DisplayStringLine(Line8,lcdtext);
}void status_process(void)
{if(process_status){switch(process_status){case 1: //状态1：等待1s内是否有按键按下{sprintf((char *)status,"      wait key 1s    ");if((uwTick-key_time_1s)>=1000) //如果1s到了，进入下一个关门状态{sprintf((char *)status,"  key_1s_yes     ");process_status = 2;}}break;case 2: //状态2：开始关门{sprintf((char *)status,"  close door     ");HAL_GPIO_WritePin(GPIOA,GPIO_PIN_5,GPIO_PIN_RESET);//关门__HAL_TIM_SET_COMPARE(&htim17,TIM_CHANNEL_1,250); //占空比50%HAL_TIM_PWM_Start(&htim17,TIM_CHANNEL_1);process_status = 3; //进入等待关门状态open_or_close_door_time_4s = uwTick;//更新关门时间}break;case 3://状态3：4s关门时间等待，关完门开始判断电梯是上行还是下行{sprintf((char *)status,"wait close door 4s    ");if(uwTick-open_or_close_door_time_4s>=4000) //关门后，开始判断上下行{sprintf((char *)status,"close door yes     ");int up = 0, down = 0;HAL_TIM_PWM_Stop(&htim17,TIM_CHANNEL_1);// 检查上行for(int i = current_floor + 1; i < 5; i++) { //如果电梯数组中存在比当前楼层高的楼层被设置if(setfloor[i] == 1) {up = 1;break;}}// 检查下行for(int i = current_floor - 1; i >= 1; i--) { //如果电梯数组中存在比当前楼层低的楼层被设置if(setfloor[i] == 1) {down = 1;break;}}// 判断方向if(up && !down) { //只有往上dir = 1;} else if(down && !up) { //只有往下dir = 0;} else if(up && down) { //上下都有，先向上dir = 1;} else {dir = 2; //都没有}sprintf((char *)status,"   move          ");sprintf((char *)lcdtext,"    dir:%d--%d",up,down);LCD_DisplayStringLine(Line9,lcdtext);if(dir==1)//上行{flow_led_enable = 1;HAL_GPIO_WritePin(GPIOA,GPIO_PIN_4,GPIO_PIN_SET);__HAL_TIM_SET_COMPARE(&htim16,TIM_CHANNEL_1,800); //占空比80%HAL_TIM_PWM_Start(&htim16,TIM_CHANNEL_1);up_or_down_dir_time_6s = uwTick;//更新上行时间process_status = 4;}else if(dir==0)//下行{flow_led_enable = 1;HAL_GPIO_WritePin(GPIOA,GPIO_PIN_4,GPIO_PIN_RESET);__HAL_TIM_SET_COMPARE(&htim16,TIM_CHANNEL_1,600); //占空比80%HAL_TIM_PWM_Start(&htim16,TIM_CHANNEL_1);up_or_down_dir_time_6s = uwTick;//更新上行时间process_status = 4;}else if(dir==2)//既不需要上行也不需要下行，回到电梯状态{process_status = 0;}}}break;case 4://状态4：等待6s上下行时间{sprintf((char *)status," wait move 6s        ");if(uwTick-up_or_down_dir_time_6s>=6000) //上下行时间到了{sprintf((char *)status," move yes       ");if(dir==1) //如果是上行{current_floor+=1;}else{current_floor-=1;}HAL_TIM_PWM_Stop(&htim16,TIM_CHANNEL_1);//setfloor[current_floor] = 0;//已到达该层// 显示楼层号并闪烁两次for(int i = 0; i < 2; i++) // 闪烁两次{sprintf((char *)lcdtext,"        %d",current_floor);LCD_DisplayStringLine(Line3, lcdtext); // 显示楼层号HAL_Delay(500); // 延时500msLCD_ClearLine(Line3); // 清除楼层号显示HAL_Delay(500); // 延时500ms}// 再次显示楼层号sprintf((char *)lcdtext,"        %d",current_floor);LCD_DisplayStringLine(Line3, lcdtext);switch(current_floor){case 1:{led &= ~0x01; // 使用位清除操作关闭LED1}break;case 2:{led &= ~0x02; // 关闭LED2}break;case 3:{led &= ~0x04; // 关闭LED3}break;case 4:{led &= ~0x08; // 关闭LED4}break;}LED_display(led); // 更新LED显示flow_led_enable = 0; // 关闭流水灯led &= 0x0F; // 保持低四位状态不变，关闭高四位LEDLED_display(led); // 更新LED显示open_or_close_door_time_4s = uwTick;//更新开门时间process_status =5;}}break;case 5 ://状态5:等待开门4s时间到{sprintf((char *)status," wait open door 4s       ");if(uwTick-open_or_close_door_time_4s>=4000)//打开门{sprintf((char *)status," open door yes     ");wait_time_2s = uwTick;//更新等待时间process_status = 6;}}break;case 6 ://状态5:等待开门4s时间到{sprintf((char *)status," wait  2s       ");if(uwTick-wait_time_2s>=2000)//每层停留时间{sprintf((char *)status," wait  2s yes     ");wait_time_2s = uwTick;//更新等待时间process_status = 2;}}break;}}}void led_process(void)
{static uint8_t flow_led_state = 0; // 初始状态为0，表示流水灯未激活if((uwTick - lastUpdateTime) >= updateInterval && flow_led_enable){lastUpdateTime = uwTick; // 更新最后一次更新时间if(flow_led_state == 0) // 如果流水灯未激活，根据方向初始化流水灯状态{flow_led_state = (dir == 1) ? 0x08 : 0x01; // 从左侧或右侧开始}else{if(dir == 1) // 上行：从右到左流水{flow_led_state <<= 1; // 向左移动if(flow_led_state > 0x08) // 如果超过了最左侧，重置到最右侧{flow_led_state = 0x01;}}else if(dir == 0) // 下行：从左到右流水{flow_led_state >>= 1; // 向右移动if(flow_led_state < 0x01) // 如果超过了最右侧，重置到最左侧{flow_led_state = 0x08;}}}// 更新LED状态，仅修改高四位，保持低四位不变// 注意：这里假设flow_led_state只影响一个LED，需要根据实际情况调整led = (led & 0x0F) | (flow_led_state << 4); // 将流水灯状态左移4位，合并到led的高四位LED_display(led); // 更新LED显示}
}/* USER CODE END 4 *//*** @brief  This function is executed in case of error occurrence.* @retval None*/
void Error_Handler(void)
{/* USER CODE BEGIN Error_Handler_Debug *//* User can add his own implementation to report the HAL error return state *//* USER CODE END Error_Handler_Debug */
}#ifdef  USE_FULL_ASSERT
/*** @brief  Reports the name of the source file and the source line number*         where the assert_param error has occurred.* @param  file: pointer to the source file name* @param  line: assert_param error line source number* @retval None*/
void assert_failed(uint8_t *file, uint32_t line)
{/* USER CODE BEGIN 6 *//* User can add his own implementation to report the file name and line number,tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) *//* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT *//************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

key.c

#include "key.h"struct Key key[4] = {0,0,0,0};extern uint8_t process_status;
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{if(htim->Instance==TIM2){if((process_status==0||process_status==1)){key[0].key_gpio = HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_0);key[1].key_gpio = HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_1);key[2].key_gpio = HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_2);key[3].key_gpio = HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0);for(int i = 0;i<4;i++){switch(key[i].key_index){case 0:{if(key[i].key_gpio==0){key[i].key_index=1;}}break;case 1:{if(key[i].key_gpio==0){key[i].key_flag =1;key[i].key_index=2;}else{key[i].key_index=0;}}break;case 2:{if(key[i].key_gpio==1){key[i].key_index=0;}}break;}}}}}

我一共将这个题目分为了6个状态

1. 状态0

此状态用于等待按键按下以设置目标楼层，只要右按键按下，就将对应的楼层数组置1，打开对应的led，记录当前按键按下的时间，最后进入状态1

2. 状态1：

此状态的进入是由于存在按键被按下，设置了目标楼层，该状态一直等待1s的到来，在状态0和状态1状态下按键仍然可以按下，因为某个按键按下后，在1s内仍然可以设置目标楼层，每一次重新按下按键，倒计时都会刷新，同样为了防止其余状态下按键仍然可以按下导致flag置1，在key.c的定时器回调函数中也只有状态0和状态1才能判断按键是否按下

3. 状态2：

此状态为开始关门状态，根据题目要求，将PA5置低电平，同时设置TIM17通道1的占空比为50% ，更新关门时间，进入状态3

4. 状态3：

题目要求开关门都需要4s，所以此状态为等待关门状态，等待结束后，开始根据setfloor数组确定当前电梯是向上，还是向下，设置的楼层会导致4种状态

• 只有比当前楼层高的楼层被设置，dir=1,往上走
• 只有比当前楼层低的楼层被设置，dir=0，往下走
• 比当前楼层高的和低的都设置，例如当前楼层是2层，比2层低的1层和比2层高的3，4层都被设置，dir=1,同样先向上走，再往下走
• 默认状态都没有被设置，在按键时已经限制条件不能设置当前楼层，dir=2，保持在当前楼层

根据dir的取值，设置上行还是下行，并打开对应PWM输出和电平信号，更新电梯开始上下行时间，或者是就在当前层然后，回到状态0，等待设置目标楼层

5. 状态4：

题目要求上行或者下行都需要6s，该状态是为了等待6s到来，时间到来后，根据dir将当前楼层+1或者-1，同时当前楼层闪烁两次，关闭当前楼层对应的led灯，关闭流水灯，然后更新开始开门时间，进入状态5

6. 状态5:

等待开门时间4s，时间到达后，更新每层停留的2s时间，进入下一个状态，状态6

7. 状态6:

每层的等待时间2s，等待完后回到，状态2开始关门，继续按顺序执行，直到没有目标楼层，回到状态0等待按键按下。

led.c

#include "led.h"void LED_display(uint8_t led)
{HAL_GPIO_WritePin(GPIOC,GPIO_PIN_All,GPIO_PIN_SET);HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_SET);HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_RESET);HAL_GPIO_WritePin(GPIOC,led<<8,GPIO_PIN_RESET);HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_SET);HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_RESET);
}

led_process用于处理流水灯，根据电梯运行方向确定，流水灯方向，led = (led & 0x0F) | (flow_led_state << 4); 这句的意思是首先保持低四位的保持不变，然后将流水灯的状态左移4位，与之相或从而实现不影响低四位led的效果

为了便于观察状态，添加了一些表示状态的信息显示在lcd上，时间控制大部分使用滴答定时器uwTick以防止delay阻塞程序