前言：STM32G431RBT6实现嵌入式组第十三届题目解析+源码，本文默认读者具备基础的stm32知识。文章末尾附有第十三届题目。
1.题目解析
第十三届题目和第十二届题目如出一辙。更甚十到十三届题目差的不多，基本一个模板，只不过十二十三多了一个uart。蓝桥杯省赛的题目确实越来越水了😅。
1.1 分而治之，藕断丝连
还是那句话，将不同模块进行封装，通过变量进行模块间的合作。
函数将模块分而治之，变量使模块间藕断丝连。
1.2 模块化思维导图
下图根据题目梳理。还是使用思维导图。
1.3 模块解析
1.3.1 KEY模块
还是控制按一次处理一次。老朋友了我们就不多说了，题目限制了按键消抖和单次处理，所以我们要加上消抖，和前几届的处理一模一样。
正常按键逻辑：
开始按下—>按下—>释放；
但是题目要求得按一次处理一次，根据代码逻辑加了一种等待释放状态
根据机械按键的特性开始和结束都得消抖，加上按一次执行一次，所以我们的处理逻辑是：
开始按下—>按下消抖—>按下—>等待弹起—>弹起—>弹起消抖—>释放；
具体看源码
if(按键按下){
if(是否是释放状态){ //开始按下
进入消抖状态，开始消抖计时
}
else if(是否是消抖状态){ //按下消抖
if(当前时间-消抖计时>=消抖时长){
消抖完成，进入按下状态
}
}
else if(是否是按下状态){ //等待弹起状态
等待释放状态
}
}
else{//没有按下
if(是否是等待释放或者按下状态){ //弹起
进入消抖状态，开始消抖计时
}
else if(是否是消抖状态){ //弹起消抖
if(当前时间-消抖计时>=消抖时长){
消抖完成，按键释放
}
}
}
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1.3.2 LED模块
ld1：密码输入成功5s后熄灭
ld2：输入密码错误三次，以0.1s间隔闪烁5s熄灭
解决办法，设置一个标志位代表ld1~ld8，改变对应位的的值，再将标志位写入ODR寄存器中来控制led的亮灭。
具体实现看源码
1.3.3 LCD模块
lcd显示两个界面，注意首次切换的时候得清屏。
根据B1界面1和界面2切换；
状态0：PSD；
状态1：STA；
具体实现看源码
1.3.4 TIM模块
TIM3产生0.1s时基。PSC：1699，ARR：9999；
TIM2通道2产生2kHzPWM。PSC：16，ARR：4999；
PSC和ARR计算公式（计算周期就是频率的倒数）：
//tim2pwm周期中断
void HAL_TIM_PWM_PulseFinishedCallback(TIM_HandleTypeDef *htim)
{
if(lcd_show_conv == 0){ //输入密码界面1KHz的方波
PWM_1KHz_flag++;
if(PWM_1KHz_flag == 2){ //两个周期高电平
TIM2->CCR2 = 4999;
}else if(PWM_1KHz_flag == 4){ //两个周期低电平
PWM_1KHz_flag = 0;
TIM2->CCR2 = 0;
}
}else{ //密码正确输出2Khz10%占空比pwm
if(tim_5s == 0) tim_5s = 1;
if(tim_5s == 51) {
lcd_show_conv = 0;
tim_5s = 0;
}
TIM2->CCR2 = 499;
}
}
//tim3 0.1s时基中断
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
if(tim_5s != 0) tim_5s++;
if(ld2_tim_5s != 0) ld2_tim_5s++;
led_process();
HAL_UARTEx_ReceiveToIdle_IT(&huart1, (uint8_t*)uart_rx_data, 7); //周期开启uart接收中断
}
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1.3.5 UART模块
十三届题目的难度就在uart的数据处理上。
1.单片机接收来自电脑固定格式的数据，我们就需要数据限制条件来写解析接收的数据。限制条件：数据长度，数据格式。
具体请看源码
1.3.5.1 uart数据解析
我们可以使用指针加for单个字符判断，也可以使用string.h库中的字符串处理函数，strcmp(), strcpy(),strncmp(), strncpy()等函数。
//解析uart接收数据，返回值测试的时候使用，成功可以不用返回值，因为不做任何处理
u8 analyze_uart_data()
{
if(strncmp(uart_rx_data, default_code, 3)) return 1; //判断前三位和默认密码是否相等
for(u8 i=4;i<7;i++){ //判断新密码格式是否正确
if(uart_rx_data[i] < '0' || uart_rx_data[i] > '9') return 2;
}
if(strncpy(default_code, uart_rx_data+4, 3)) return 3; //判断密码是否改成功
return 0;
}
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2.源码
我所有的实现都在main.c文件中。
2.1cubemx配置
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2025 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "tim.h"
#include "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "stdio.h"
#include "lcd.h"
#include "string.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* 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 */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
//按键的四种状态
enum{
key_released = 0U,
key_pressed,
key_wait_released,
key_reduction,
};
//按键消抖开始时间标记
uint32_t key_redu = 0;
/*
keys_state: 按键状态
keys_volt: 按键对应gpio电平状态
*/
uint8_t keys_state[4] = {0}, keys_volt[4] = {0};
/*
set_code: 设置密码存储位置
default_code: 默认密码存储位置
lcd_str: lcd显示
uart_rx_data: 串口接收数据
*/
char set_code[4] = {'@','@','@'}, default_code[4] = {'1', '2', '3', '\0'}, lcd_str[21] = {0},uart_rx_data[8] = {0};
/*
lcd_show_conv: lcd界面切换标志
B1_3_limit: 上电默认密码值限制
lcd_clear_flag: lcd清屏标志
PWM_1KHz_flag: pwm输出1KHz标志
tim_5s: 密码正确，涉及的计时操作
ld2_tim_5s: ld2跟上面的是独立事件，单独计时
code_error_cnt: 错误计数
ld_flag: led状态标记
*/
uint8_t lcd_show_conv = 0, B1_3_limit = 0, lcd_clear_flag = 0, PWM_1KHz_flag = 0, tim_5s = 0, ld2_tim_5s = 0,
code_error_cnt = 0, ld_flag = 0;
void key_state_gain();
void key_process();
void lcd_process();
void led_process();
u8 analyze_uart_data();
/* 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 */
LCD_Init();
LCD_Clear(Black);
LCD_SetBackColor(Black);
LCD_SetTextColor(White);
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_TIM2_Init();
MX_TIM3_Init();
MX_USART1_UART_Init();
/* USER CODE BEGIN 2 */
HAL_TIM_Base_Start_IT(&htim3);
HAL_TIM_PWM_Start_IT(&htim2, TIM_CHANNEL_2);
HAL_UARTEx_ReceiveToIdle_IT(&huart1, (uint8_t*)uart_rx_data, 7);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
key_state_gain();
key_process();
lcd_process();
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Configure the main internal regulator output voltage
*/
HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1_BOOST);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = RCC_PLLM_DIV6;
RCC_OscInitStruct.PLL.PLLN = 85;
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_4) != HAL_OK)
{
Error_Handler();
}
}
/* USER CODE BEGIN 4 */
//获取按键状态
void key_state_gain()
{
keys_volt[0] = HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_0);
keys_volt[1] = HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_1);
keys_volt[2] = HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_2);
keys_volt[3] = HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0);
for(uint8_t i=0;i<4;i++){
//开始按下>>>消抖>>>按下>>>消抖>>>释放
if(keys_volt[i] == 0)
{
if(keys_state[i] == key_released){
keys_state[i] = key_reduction;
key_redu = HAL_GetTick();
}
else if(keys_state[i] == key_reduction){
if(HAL_GetTick() - key_redu>=10){
keys_state[i] = key_pressed;
}
}
else if(keys_state[i] == key_pressed){
keys_state[i] = key_wait_released;
}
}
else{
if(keys_state[i] == key_pressed || keys_state[i] == key_wait_released)
{
keys_state[i] = key_reduction;
key_redu = HAL_GetTick();
}
else if(keys_state[i] == key_reduction){
if(HAL_GetTick() - key_redu>=10){
keys_state[i] = key_released;
}
}
}
}
}
//设置按键对应标志位
void key_process()
{
if(lcd_show_conv == 0){
for(uint8_t i=0;i<3;i++){
if(keys_state[i] == key_pressed)
{
B1_3_limit = 1;
if(set_code[i] == '@') set_code[i] = '0';
else{
set_code[i]++;
if(set_code[i]>'9') set_code[i] = '0';
}
}
}
}
if(B1_3_limit == 0){
for(uint8_t i=0;i<3;i++){
set_code[i] = '@';
}
set_code[3] = '\0';
}
if(keys_state[3] == key_pressed)
{
B1_3_limit = 0;
if(!strcmp(set_code, default_code)){
lcd_show_conv ^= 1;
}else{
code_error_cnt++;
}
}
}
//lcd显示界面1，界面2
void lcd_process()
{
switch(lcd_show_conv)
{
case 0:
if(lcd_clear_flag == 1){
lcd_clear_flag = 0;
LCD_Clear(Black);
}
sprintf(lcd_str, " PSD ");
LCD_DisplayStringLine(Line2, (uint8_t*)lcd_str);
sprintf(lcd_str, " B1:%c ", set_code[0]);
LCD_DisplayStringLine(Line4, (uint8_t*)lcd_str);
sprintf(lcd_str, " B2:%c ", set_code[1]);
LCD_DisplayStringLine(Line5, (uint8_t*)lcd_str);
sprintf(lcd_str, " B3:%c ", set_code[2]);
LCD_DisplayStringLine(Line6, (uint8_t*)lcd_str);
break;
case 1:
if(lcd_clear_flag == 0){
lcd_clear_flag = 1;
LCD_Clear(Black);
}
sprintf(lcd_str, " STA ");
LCD_DisplayStringLine(Line2, (uint8_t*)lcd_str);
sprintf(lcd_str, " F:2000Hz ");
LCD_DisplayStringLine(Line4, (uint8_t*)lcd_str);
sprintf(lcd_str, " D:10%% ");
LCD_DisplayStringLine(Line5, (uint8_t*)lcd_str);
break;
}
}
//led控制
void led_process()
{
if(tim_5s != 0){
ld_flag = 1;
}else{
ld_flag = 0;
}
if(code_error_cnt == 3){
code_error_cnt = 0;
ld2_tim_5s = 1;
}
if(ld2_tim_5s != 0){
if(ld2_tim_5s == 51) ld2_tim_5s = 0;
ld_flag += ld2_tim_5s%2 == 0 ? (0<<1):(1<<1);
}else{
ld_flag += 0<<1;
}
HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2, 1);
GPIOC->ODR = 0xffff ^ (ld_flag << 8);
HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2, 0);
}
//解析uart接收数据，返回值测试的时候使用，成功可以不用返回值，因为不做任何处理
u8 analyze_uart_data()
{
if(strncmp(uart_rx_data, default_code, 3)) return 1; //判断前三位和默认密码是否相等
for(u8 i=4;i<7;i++){ //判断新密码格式是否正确
if(uart_rx_data[i] < '0' || uart_rx_data[i] > '9') return 2;
}
if(strncpy(default_code, uart_rx_data+4, 3)) return 3; //判断密码是否改成功
return 0;
}
//tim2pwm周期中断
void HAL_TIM_PWM_PulseFinishedCallback(TIM_HandleTypeDef *htim)
{
if(lcd_show_conv == 0){ //输入密码界面1KHz的方波
PWM_1KHz_flag++;
if(PWM_1KHz_flag == 2){ //两个周期高电平
TIM2->CCR2 = 4999;
}else if(PWM_1KHz_flag == 4){ //两个周期低电平
PWM_1KHz_flag = 0;
TIM2->CCR2 = 0;
}
}else{ //密码正确输出2Khz10%占空比pwm
if(tim_5s == 0) tim_5s = 1;
if(tim_5s == 51) {
lcd_show_conv = 0;
tim_5s = 0;
}
TIM2->CCR2 = 499;
}
}
//tim3 0.1s时基中断
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
if(tim_5s != 0) tim_5s++;
if(ld2_tim_5s != 0) ld2_tim_5s++;
led_process();
HAL_UARTEx_ReceiveToIdle_IT(&huart1, (uint8_t*)uart_rx_data, 7); //周期开启uart接收中断
}
//uart接收事件中断
void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size)
{
analyze_uart_data();
}
/* 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 */
__disable_irq();
while (1)
{
}
/* 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,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
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3.第十三届题目
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