stm32学习总结：5、Proteus8+STM32CubeMX+MDK仿真串口并使用串口打印日志（注意重定向printf到串口打印的问题）

一、前言

上一节模拟实现了串口收发打印，一般我们裸机打印日志通过串口或者JLINK工具等带的RTT打印，对于仿真，我们选择使用串口打印再合适不过了，这里总结一下重定向printf到串口打印日志的过程；期间，尝试了CLion+arm gcc的方式，发现stm32f10x的flash还是支撑不起来未裁剪的标准库，只要使用stdio相关标准库编译时就很容易flash超标。

二、资料收集

https://blog.csdn.net/m0_54490453/article/details/128921674
https://www.cnblogs.com/pianist/p/3315801.html
https://blog.51cto.com/u_13682052/5670642
STM32串口使用printf打印日志：
https://community.st.com/t5/stm32-mcus-products/how-to-get-printf-example-working-in-another-project/m-p/392014
https://community.st.com/t5/stm32-mcus-products/stm32g0-redirect-printf-to-write-and-use-uart-how-to/m-p/66318

三、注意事项

如果是使用arm gcc编译器的，尽量不要使用printf，这会引入标准库，而对应库不像mdk的microlib做了裁剪，它是比较占用flash的，而stm3210x的flash最多只有32KB，很容易在编译时出现section .rodata’ will not fit in region FLASH'也就是超出flash范围的问题：

网上所说的修改xxx.ld配置文件这些方法很多时候是无效的，不能盲目去修改flash配置。
可以使用比如RTT打印等方式来打印日志，也可以换一些资源比较丰富的板子，也许官方可以出一些裁剪过的利用arm-none-eabi gcc编译的标准库（后面有机会的话我会来尝试一下，用stm32F10x的话arm gcc基本上没办法用printf，引入标准库加上一两个简单的外设接口就肯定会flash超标，用mdk原有的编译器就不会有这个问题）。

四、STM32CubeMX配置

这次彻底精简一下相关配置：

• 1、一个按钮BUTTON，PA1配置GPIO OUTPUT用来接入按钮，使用默认配置即可，默认低电平，未拉高拉低，添加用户标签BUTTON：

• 2、五个LED，PA4-PA8配置GPIO OUTPUT用来接入LED，使用默认配置即可，默认低电平，未拉高拉低，添加用户标签LED_1到LED_5：

• 3、开启USART1，PA9\PA10来作为打印的串口，配置只发送，波特率设置为9600，不需要配置全局中断，我们使用该串口作为打印串口，只需要发送即可，所以不需要配置中断方式来接收：

然后生成代码即可。

五、MDK工程相关代码

1、非中断方式的按键处理

通过读取IO口的电平判断是否按下按钮，之后通过全局变量确认按下松开以及长短按，这种方式在理解上比较直观（按键这里的处理逻辑是判断LED灯1的电平变化来确定是否开关机，开关机的逻辑我们通过控制LED灯的亮灭来展示）：

#include "gpio.h"
#include "key.h"
#include "pwr.h"
//#include "log.h"// 按键的键值
#define KEY_Press 1// 读取IO口的电平
#define KEY_PWR HAL_GPIO_ReadPin(GPIOA, BUTTON_Pin)uint8_t key_old, count;uint8_t ScanKey(void)
{if (GPIO_PIN_RESET == KEY_PWR) {HAL_Delay(40);//延时10-20ms，防抖if (GPIO_PIN_SET == KEY_PWR) {count++;return KEY_Press;}} else {HAL_Delay(40);}return 0;
}void DealKey(void)
{uint8_t key_value = 0;//获取键值key_value = ScanKey();if (key_value != key_old) {//与上一次的键值比较 如果不相等，表明有键值的变化，开始计时key_old = key_value;count = 0;} else {//如果没有键值的改变 说明没有新按键按下或松开key_value = 0;}if (key_value)// 短按处理{switch(key_value) {case 1 : {//LOG(LOG_DEBUG, "KEY1 switch");if (GPIO_PIN_SET == HAL_GPIO_ReadPin(GPIOA, LED_1_Pin)) {//LOG(LOG_DEBUG, "pwr on");PWROn();} else {//LOG(LOG_DEBUG, "pwr off");PWROff();key_old = key_value;}}break;case 2 : {
//                LOG(DEBUG, "KEY2 switch");}break;}key_value = 0;}return;
}

#ifndef __KEY_H
#define __KEY_H#include "main.h"void DealKey(void);#endif

2、开关机业务

这里暂时通过LED灯亮灭来模拟，后续可增加底板电路的控制、蜂鸣器的控制等，基本都是通过控制IO口高低电平方式来控制的：

#include "pwr.h"
#include "log.h"
#include "gpio.h"void TurnOnLED(int flag)
{switch(flag){case 1:HAL_GPIO_WritePin(GPIOA, LED_1_Pin, GPIO_PIN_RESET);break;case 2:HAL_GPIO_WritePin(GPIOA, LED_2_Pin, GPIO_PIN_RESET);break;case 3:HAL_GPIO_WritePin(GPIOA, LED_3_Pin, GPIO_PIN_RESET);break;case 4:HAL_GPIO_WritePin(GPIOA, LED_4_Pin, GPIO_PIN_RESET);break;case 5:HAL_GPIO_WritePin(GPIOA, LED_5_Pin, GPIO_PIN_RESET);break;}
}void TurnOffLED(int flag)
{switch(flag){case 1 :HAL_GPIO_WritePin(GPIOA, LED_1_Pin, GPIO_PIN_SET);break;case 2 :HAL_GPIO_WritePin(GPIOA, LED_2_Pin, GPIO_PIN_SET);break;case 3 :HAL_GPIO_WritePin(GPIOA, LED_3_Pin, GPIO_PIN_SET);break;case 4 :HAL_GPIO_WritePin(GPIOA, LED_4_Pin, GPIO_PIN_SET);break;case 5 :HAL_GPIO_WritePin(GPIOA, LED_5_Pin, GPIO_PIN_SET);break;}
}void PWROn(void)
{LOG(LOG_DEBUG, "PWROn LED blink...");for (int i = 1; i< 6; i++) {HAL_Delay(100);TurnOnLED(i);}
}void PWROff(void)
{LOG(LOG_DEBUG, "PWROn LED off...");for (int i = 1; i< 6; i++) {HAL_Delay(100);TurnOffLED(i);}
}

#ifndef __PWR_H
#define __PWR_H#include "main.h"void PWROn(void);void PWROff(void);#endif

3、printf重定向到串口打印

通过stm32的官方论坛和一些参考文章发现是通过对printf进行重写来将发送到终端输出设备的内容通过串口发送出来，不同的编译器链接的库的printf底层调用方式可能有差异，需要注意一下。目前官方论坛上给到的方式是通过宏PUTCHAR_PROTOTYPE控制，我尝试去寻找对应printf的源码，mdk库的printf源码没有找到，据网上说其裁剪的标准库实现的printf是用fputc来将字符发送出去的，而gun c标准库的printf最终查看源码发现是通过调用write函数写入到显示设备的，而该函数为系统调用，系统通过驱动调用硬件IO口去控制显示设备将写入的内容显示，对于没有系统的stm32裸机来说其封装了一个__io_putchar的类似系统调用（其文件名字就叫syscalls.c）接口来让我们重写输出方式，这样我们重写PUTCHAR_PROTOTYPE即可，目前在main.c中添加对应宏控制并重写将写入的ch字符通过串口写入：

#ifdef __GNUC__/* With GCC, small printf (option LD Linker->Libraries->Small printfset to 'Yes') calls __io_putchar() */#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)#else#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)#endif /* __GNUC__ */PUTCHAR_PROTOTYPE{/* Place your implementation of fputc here *//* e.g. write a character to the EVAL_COM1 and Loop until the end of transmission */HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);return ch;}

整体main.c，大循环中调用按钮监听处理：

/* USER CODE BEGIN Header */
/********************************************************************************* @file           : main.c* @brief          : Main program body******************************************************************************* @attention** Copyright (c) 2024 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 "usart.h"
#include "gpio.h"/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "key.h"
#include "stdio.h"/* USER CODE BEGIN 0 *//* 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 *//* 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 *//* 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 *//* 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 *//* 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 *//* USER CODE END Includes *//* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD *//* USER CODE END PTD *//* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#ifdef __GNUC__/* With GCC, small printf (option LD Linker->Libraries->Small printfset to 'Yes') calls __io_putchar() */#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)#else#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)#endif /* __GNUC__ */PUTCHAR_PROTOTYPE
{/* Place your implementation of fputc here *//* e.g. write a character to the EVAL_COM1 and Loop until the end of transmission */HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);return ch;
}
/* 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 *//* 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 *//* 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_USART1_UART_Init();/* USER CODE BEGIN 2 *//* USER CODE END 2 *//* Infinite loop *//* USER CODE BEGIN WHILE */while (1){/* USER CODE END WHILE *//* USER CODE BEGIN 3 */DealKey();}/* USER CODE END 3 */
}/*** @brief System Clock Configuration* @retval None*/
void SystemClock_Config(void)
{RCC_OscInitTypeDef RCC_OscInitStruct = {0};RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};/** Initializes the RCC Oscillators according to the specified parameters* in the RCC_OscInitTypeDef structure.*/RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;RCC_OscInitStruct.HSIState = RCC_HSI_ON;RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;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_HSI;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_0) != HAL_OK){Error_Handler();}
}/* USER CODE BEGIN 4 *//* 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 */

4、日志打印封装

然后我们将printf函数稍微封装一下，也可以使用easylogger日志库：

#include "log.h"
#include "usart.h"char* get_log_level_str(const int level)
{if (level == LOG_DEBUG) {return "DEBUG";}else if (level == LOG_INFO) {return "INFO";}else if (level == LOG_WARN) {return "WARN";}return "UNLNOW";
}void my_log(const int level,const char* fun, const int line ,const char* fmt, ...)
{
#ifdef OPEN_LOGva_list arg;va_start(arg, fmt);char buf[50] = { 0 };vsnprintf(buf, sizeof(buf), fmt, arg);va_end(arg);if (level >= LOG_LEVEL)printf("[%-5s] [%-20s%4d] %s \r\n", get_log_level_str(level), fun, line, buf);
#endif
}

#ifndef __LOG_H_
#define __LOG_H_#include <stdarg.h>
#include <stdio.h>
#define OPEN_LOG 1
#define LOG_LEVEL LOG_DEBUGtypedef enum
{LOG_DEBUG = 0,LOG_INFO,LOG_WARN
}E_LOGLEVEL;void my_log(const int level, const char* fun, const int line, const char* fmt, ...);
#define LOG(level,fmt,...) my_log(level,__FUNCTION__,__LINE__,fmt, ##__VA_ARGS__)#endif

这样我们调用LOG()进行日志打印就可以了，和常规软件开发的日志打印接口基本就一致了。

六、Proteus项目配置

Proteus创建串口和虚拟终端、LED灯、电阻灯我们之前已经总结过了，不再重复，这里再添加一个按键即可，按下P，搜索BUTTON即可添加，之后按如下方式接线：

串口TX、RX和之前接法一样，还需要配置其波特率，也和之前一样，虚拟终端这里有一些区别，上节我们是TX、RX是和串口对应一致的，但是这里我们要显示串口发送的内容，所以RX接入串口的TX，不要搞错了，而且由于是显示日志的打印串口，我们配置的只发送，所以理论上RX是可以不接的。至于其它的接线基本没有什么注意的，和之前的大体一致，主要注意控制开关的高低电平即可，一端接电源，另一端设置低电平即导通，电流流过。

七、仿真测试结果

按下按键根据key.c中的处理逻辑就会来回判断进行开关机业务处理了，这里模拟开关机通过LED灯的亮灭来展示，串口的TX发送接入虚拟终端RX将发送的日志直接显示出来了，串口工具在Windows上打开对端的串口也是可以看到对应的信息的（快去试一下吧）：

八、最后

下一节我们来试下ADC和蜂鸣器的使用吧，蜂鸣器这种简单的音频提示元器件也是用的比较广泛的，比较常见的像小区的门禁基本都会加蜂鸣器提示刷卡是否成功等，ADC接口则常常用来读取一些传感器的信息或者电压信息等，也是比较常用的。最近的一些总结基本都是用为主，对于这些IO口的更深层次的配置及控制原理我们暂时不做深入分析，只需要了解怎么用即可，这些东西感觉总结C51的时候来分析总结更合适一些，C51的应用相对简单一些，STM32的应用开发已经比较接近Linux应用开发这种层级，很多时候不用太考虑底层的实现，只需要会用接口开发比较复杂的应用即可（所以这种应用开发实时操作系统的学习就比较重要了），等到解决一些疑难杂症时，再对其做深入了解和理解，新手直接深入容易被劝退。