蓝桥杯嵌入式组第十四届省赛题目解析+STM32G431RBT6实现源码
文章目录
- 1.题目解析
- 1.1 分而治之,藕断丝连
- 1.2 模块化思维导图
- 1.3 模块解析
- 1.3.1 KEY模块
- 1.3.2 LED模块
- 1.3.3 LCD模块
- 1.3.4 TIM模块
- 1.3.4.1 频率变化处理
- 1.3.4.1 占空比计算
- 1.3.5 ADC模块
- 2.源码
- 2.1cubemx配置
- 3.第十四届题目
前言:STM32G431RBT6实现嵌入式组第十四届题目解析+源码,本文默认读者具备基础的stm32知识。文章末尾附有第十四届题目。
1.题目解析
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,和第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—>短按—>等待弹起—>长按—>弹起—>弹起消抖—>释放;
为了实现按一次执行一次,中间加了一个等待弹起状态(key_state_gain()函数获取到按键状态,key_state_set()设置按键对应按键涉及标志位,下一次进入到key_state_gain()函数中,按键状态就变成了等待弹起状态,这就保证了,短按长按只执行key_state_set()一次)
这里主要说逻辑,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(是否是短按状态 || 是否是长按状态){ //等待弹起状态
等待释放状态
记录长按2s开始时间
}
else if(是否是等待状态){ //长按实现
if(时间达到2s) 长按状态
}
}
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
}
}
}
1.3.2 LED模块
ld1:数据界面亮,否则灭;
ld2:频率切换期间,以0.1s间隔闪烁;
ld3:占空比锁定亮,否则灭;
其他led保持熄灭状态。
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显示三个界面,注意首次切换的时候得清屏。
根据B1进行三个界面的切换;
状态0:DATA;
状态1:PARA;
状态1:RECD。
具体实现看源码
1.3.4 TIM模块
TIM4产生0.1s时基。PSC:1699,ARR:9999;
TIM2,chn2: 16, 2499 , 4KHzPWM;
TIM3,chn2: 169, 9999, 捕获范围T<=10ms。
PSC和ARR计算公式(计算周期就是频率的倒数):
1.3.4.1 频率变化处理
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
tim_100ms ^= 1;
if(freq_conv_5s != 0){ //频率转换开始
freq_conv_5s++;
}
Hv_2s = Hv_2s < 20 ? Hv_2s+1 : 20; //最大值保持2s计时
Lv_2s = Lv_2s < 20 ? Lv_2s+1 : 20;
if(freq_conv_5s > 1){ //设置对应的输出频率
if(current_freq_mode == 0){
current_ARR -= 25;
TIM2->ARR = current_ARR;
TIM2->CCR2 = (uint32_t)current_ARR*old_duty;
}
else{
current_ARR += 25;
TIM2->ARR = current_ARR;
TIM2->CCR2 = (uint32_t)current_ARR*old_duty;
}
if(freq_conv_5s == 51){
freq_conv_5s = 0;
current_freq_mode ^= 1;
conv_N++;
}
}
led_process();
HAL_ADC_Start_IT(&hadc2);
}
1.3.4.1 占空比计算
看图可以知道这是一个分段函数。
我们可以这样解决
float caculate_duty()
{
if(adc_smp_volt<=1.0){
return 0.1;
}
else if(adc_smp_volt>1.0 && adc_smp_volt<=3.0){
return (0.375*adc_smp_volt - 0.275);
}
else return 0.85;
}
1.3.5 ADC模块
这里adc采集R37电位器电压,这里就不多说。
具体请看源码
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 "adc.h"
#include "tim.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "stdio.h"
#include "string.h"
#include "lcd.h"
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define PI 3.14
/* 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 */
//按键状态
enum{
key_released = 0U,
key_reduction,
key_short_pressed,
key_wait_pressed,
key_long_pressed,
};
//记录低频和高频速度
struct{
float ML_new;
float MH_new;
float ML_old;
float MH_old;
} max_v = {0.0f};
/*
adc_smp_volt: adc采集电压
current_duty: 实时占空比
old_duty: 保持占空比,比如锁定会记录上一次占空比
*/
float adc_smp_volt = 0.0f, current_duty = 0.0f, old_duty = 0.0f;
/*
keys_volt: 按键电平
keys_state: 按键状态
RK_val: 实际起作用的RK值
RK_val_set: 设置时候的RK值
*/
uint8_t keys_volt[4] = {0}, keys_state[4] = {0}, RK_val[2] = {1,1}, RK_val_set[2] = {1,1};
/*
key_redu: 记录消抖时间戳
key_long_2s: 长按时间戳
current_ARR: tim3的arr值
IC_freq: 捕获到的频率
conv_N: 界面三N的值
*/
uint32_t key_redu = 0, key_long_2s = 0, current_ARR = 2499, IC_freq = 0, conv_N = 0;
/*
lcd_show_conv: 界面切换标志
RK_choose_conv: RK按键切换选择
freq_conv_5s: 切换5s计时
duty_lock: 锁定标志
current_freq_mode: pinlv模式
Hv_2s: 高频速度2s计时
Lv_2s: 低频速度2s计时
lcd_clear_flag: 界面刷新
ld_flag: led控制标志
tim_100ms: 100ms标志
*/
uint8_t lcd_show_conv = 0, RK_choose_conv = 0,freq_conv_5s = 0, duty_lock = 0, current_freq_mode = 0,
Hv_2s = 0, Lv_2s = 0, lcd_clear_flag = 0, ld_flag = 0, tim_100ms = 0;
/*
old_IC_val: 采集CCR值,计算频率
new_IC_val: 采集CCR值
*/
uint16_t old_IC_val = 0, new_IC_val = 0;
//lcd显示
char lcd_str[25] = {0};
void key_state_gain();
void key_process();
void lcd_process();
void led_process();
float caculate_duty();
void caculate_v();
/* 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 */
LCD_Init();
LCD_Clear(Black);
LCD_SetBackColor(Black);
LCD_SetTextColor(White);
/* 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_TIM3_Init();
MX_TIM4_Init();
MX_ADC2_Init();
/* USER CODE BEGIN 2 */
HAL_ADCEx_Calibration_Start(&hadc2, ADC_SINGLE_ENDED);
HAL_TIM_Base_Start_IT(&htim4);
HAL_TIM_PWM_Start_IT(&htim2, TIM_CHANNEL_2);
HAL_TIM_IC_Start_IT(&htim3, TIM_CHANNEL_2);
HAL_ADC_Start_IT(&hadc2);
/* 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();
caculate_v();
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++){
if(keys_volt[i] == 0){
if(keys_state[i] == key_released){
key_redu = HAL_GetTick();
keys_state[i] = key_reduction;
}
else if(keys_state[i] == key_reduction){
if(HAL_GetTick()-key_redu>=10){
keys_state[i] = key_short_pressed;
key_long_2s = HAL_GetTick();
}
}
else if(keys_state[i] == key_short_pressed){
keys_state[i] = key_wait_pressed;
}
else if(keys_state[i] == key_wait_pressed){
if(HAL_GetTick() - key_long_2s>=2000){
keys_state[i] = key_long_pressed;
}
}
else if(keys_state[i] == key_long_pressed){
keys_state[i] = key_wait_pressed;
}
}
else{
if(keys_state[i] == key_short_pressed || keys_state[i] == key_wait_pressed ||
keys_state[i] == key_long_pressed){
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;
}
}
}
}
}
//根据按键状态设置对应标志位
void key_process()
{
if(keys_state[0] == key_short_pressed){
lcd_show_conv = lcd_show_conv!=2 ? lcd_show_conv+1 : 0;
if(lcd_show_conv == 2){
RK_val[0] = RK_val_set[0];
RK_val[1] = RK_val_set[1];
}
}
if(keys_state[1] == key_short_pressed){
if(lcd_show_conv == 0){
if(freq_conv_5s == 0){
freq_conv_5s = 1;
old_duty = current_duty;
}
}
else if(lcd_show_conv == 1){
RK_choose_conv ^= 1;
}
}
if(keys_state[2] == key_short_pressed){
if(lcd_show_conv == 1){
RK_val_set[RK_choose_conv] = RK_val_set[RK_choose_conv]<10?RK_val_set[RK_choose_conv]+1:10;
}
}
if(keys_state[3] == key_short_pressed){
if(lcd_show_conv == 1){
RK_val_set[RK_choose_conv] = RK_val_set[RK_choose_conv]>1?RK_val_set[RK_choose_conv]-1:1;
}
duty_lock = 0;
}
if(keys_state[3] == key_long_pressed){
duty_lock = 1;
old_duty = current_duty;
}
}
//lcd显示
void lcd_process()
{
switch(lcd_show_conv){
case 0:
if(lcd_clear_flag == 2){
LCD_Clear(Black);
lcd_clear_flag = 0;
}
LCD_DisplayStringLine(Line1, (uint8_t*)" DATA ");
if(current_freq_mode == 0)
sprintf(lcd_str, " M=L ");
else
sprintf(lcd_str, " M=H ");
LCD_DisplayStringLine(Line3, (uint8_t*)lcd_str);
if(duty_lock == 1 || freq_conv_5s != 0) {
sprintf(lcd_str, " P=%d%% ", (int)(old_duty*100));
}
else
sprintf(lcd_str, " P=%d%% ", (int)(current_duty*100));
LCD_DisplayStringLine(Line4, (uint8_t*)lcd_str);
sprintf(lcd_str, " V=%.1f ", (float)IC_freq*PI*RK_val[0]/50.0/RK_val[1]);
LCD_DisplayStringLine(Line5, (uint8_t*)lcd_str);
break;
case 1:
if(lcd_clear_flag == 0){
LCD_Clear(Black);
lcd_clear_flag = 1;
}
LCD_DisplayStringLine(Line1, (uint8_t*)" PARA ");
sprintf(lcd_str, " R=%hhu ", RK_val_set[0]);
LCD_DisplayStringLine(Line3, (uint8_t*)lcd_str);
sprintf(lcd_str, " K=%hhu " , RK_val_set[1]);
LCD_DisplayStringLine(Line4, (uint8_t*)lcd_str);
break;
case 2:
if(lcd_clear_flag == 1){
LCD_Clear(Black);
lcd_clear_flag = 2;
}
LCD_DisplayStringLine(Line1, (uint8_t*)" RECD ");
sprintf(lcd_str, " N=%u ", conv_N);
LCD_DisplayStringLine(Line3, (uint8_t*)lcd_str);
sprintf(lcd_str, " MH=%.1f ", max_v.MH_old);
LCD_DisplayStringLine(Line4, (uint8_t*)lcd_str);
sprintf(lcd_str, " ML=%.1f ", max_v.ML_old);
LCD_DisplayStringLine(Line5, (uint8_t*)lcd_str);
break;
}
}
//led处理
void led_process()
{
if(lcd_show_conv == 0){
ld_flag = 1;
}else ld_flag = 0;
if(freq_conv_5s!=0){
ld_flag += tim_100ms << 1;
}
if(duty_lock == 1){
ld_flag += 1<<2;
}
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_2,1);
GPIOC->ODR = 0xffff ^ ld_flag << 8;
HAL_GPIO_WritePin(GPIOD, GPIO_PIN_2,0);
}
//计算占空比
float caculate_duty()
{
if(adc_smp_volt<=1.0) return 0.1;
else if(adc_smp_volt>1.0 && adc_smp_volt<3.0) return 0.375*adc_smp_volt - 0.275;
else return 0.85;
}
//计算速度最大值
void caculate_v(){
static float maxl = 0, maxh = 0;
if(maxh != max_v.MH_new){
Hv_2s = 0;
maxh = max_v.MH_new;
}
else{
if(Hv_2s == 20 && max_v.MH_old < maxh){
max_v.MH_old = maxh;
}
}
if(maxl != max_v.ML_new){
Lv_2s = 0;
maxl = max_v.ML_new;
}
else{
if(Lv_2s == 20 && max_v.ML_old < maxl){
max_v.ML_old = maxl;
}
}
}
void HAL_TIM_PWM_PulseFinishedCallback(TIM_HandleTypeDef *htim)
{
if(duty_lock == 1){ //锁定状态占空比不变
TIM2->CCR2 = (uint32_t)current_ARR*old_duty;
}
else{
TIM2->CCR2 = (uint32_t)current_ARR*current_duty;
}
}
void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim)
{
new_IC_val = TIM3 -> CCR2; //采集ccr值
if(new_IC_val > old_IC_val){
IC_freq = 100*10000/(new_IC_val - old_IC_val); //f2 = f1的arr /f2的arr * f1
}
else{
IC_freq = 100*10000/(new_IC_val + 10000 - old_IC_val);
}
old_IC_val = new_IC_val;
if(current_freq_mode == 0){ //根据模式计算更新速度最大值
max_v.ML_new = (float)IC_freq*PI*RK_val[0]/50.0/RK_val[1];
}else max_v.MH_new = (float)IC_freq*PI*RK_val[0]/50.0/RK_val[1];
}
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
tim_100ms ^= 1;
if(freq_conv_5s != 0){ //频率转换开始
freq_conv_5s++;
}
Hv_2s = Hv_2s < 20 ? Hv_2s+1 : 20; //最大值保持2s计时
Lv_2s = Lv_2s < 20 ? Lv_2s+1 : 20;
if(freq_conv_5s > 1){ //设置对应的输出频率
if(current_freq_mode == 0){
current_ARR -= 25;
TIM2->ARR = current_ARR;
TIM2->CCR2 = (uint32_t)current_ARR*old_duty;
}
else{
current_ARR += 25;
TIM2->ARR = current_ARR;
TIM2->CCR2 = (uint32_t)current_ARR*old_duty;
}
if(freq_conv_5s == 51){
freq_conv_5s = 0;
current_freq_mode ^= 1;
conv_N++;
}
}
led_process();
HAL_ADC_Start_IT(&hadc2);
}
void HAL_ADC_ConvCpltCallback(ADC_HandleTypeDef *hadc)
{
adc_smp_volt = HAL_ADC_GetValue(hadc)*3.3/4096;
current_duty = caculate_duty();
}
/* 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 */
3.第十四届题目