STM32存储左右互搏 USB接口FATS文件读写U盘

STM32的USB接口可以例化为Host主机从而对U盘进行操作。SD卡/MicroSD/TF卡也可以通过读卡器转换成U盘使用。这里介绍STM32CUBEIDE开发平台HAL库实现U盘FATS文件访问的例程。

USB接口介绍

常见的USB接口电路部分相似而有不同的连接器应用，连接器有USB-A, USB-MINI, USB-MICRO, USB-TYPEC等。除了USB-A可以直接插入U盘,其它连接器可以通过转接板和转接线和U盘连接。如果用USB-TYPEC公头的U盘，则可以直接插入USB-TYPEC母座的主机。

常见USB-TYPEC接口电路如下：

去繁化简，主要是5V电源输入，接地，差分信号+ （DP）， 差分信号- （DN）4个有效连接。对于STM32, DP连接到了PA12管脚， DN连接到了PA11管脚.

例程采用STM32F401CCU6芯片(兼容STM32F401RCT6, 仅封装不同)对U盘进行识别和读写操作。工程平台为STM32CUBEIDE。

STM32工程配置

首先建立基本工程并设置时钟，USB应用需要采用外部晶体时钟:

配置UART1作为通讯控制口：



配置USB接口：


配置U盘接口：

需要单独配置一个不用的GPIO作为输出，并在U盘接口配置参数里选择，这个管脚实际是对应对U盘供电的开关控制，很多板上没有设计出来。


再增加一个LED指示灯的控制管脚，这里是PC13，用于U盘操作过程中的指示。

然后配置FATS文件操作参数：




保存并生成初始工程代码:

STM32工程代码

UART串口printf打印输出实现参考：STM32 UART串口printf函数应用及浮点打印代码空间节省 (HAL)

功能代码里实现对USB进行轮询检测，当检测到U盘插入后进行闪灯，当U盘准好操作时保持亮灯。
通过串口发送单字节指令，进行控制操作：
0x01: 装载USB FATS系统
0x02: 创建/打开文件并从头位置写入数据
0x02: 打开文件并从头位置读入数据
0x02: 创建/打开文件并从特定位置写入数据
0x02: 打开文件并从特定位置读入数据

完整的main.c文件如下：

/* USER CODE BEGIN Header */
/********************************************************************************* @file           : main.c* @brief          : Main program body******************************************************************************* @attention** Copyright (c) 2023 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.********************************************************************************/
//Written by Pegasus Yu in 2023
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "fatfs.h"
#include "usb_host.h"/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "stdio.h"
#include "ctype.h"
#include "string.h"#include "usart.h"
/* USER CODE END Includes *//* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
__IO float usDelayBase;
void PY_usDelayTest(void)
{__IO uint32_t firstms, secondms;__IO uint32_t counter = 0;firstms = HAL_GetTick()+1;secondms = firstms+1;while(uwTick!=firstms) ;while(uwTick!=secondms) counter++;usDelayBase = ((float)counter)/1000;
}void PY_Delay_us_t(uint32_t Delay)
{__IO uint32_t delayReg;__IO uint32_t usNum = (uint32_t)(Delay*usDelayBase);delayReg = 0;while(delayReg!=usNum) delayReg++;
}void PY_usDelayOptimize(void)
{__IO uint32_t firstms, secondms;__IO float coe = 1.0;firstms = HAL_GetTick();PY_Delay_us_t(1000000) ;secondms = HAL_GetTick();coe = ((float)1000)/(secondms-firstms);usDelayBase = coe*usDelayBase;
}void PY_Delay_us(uint32_t Delay)
{__IO uint32_t delayReg;__IO uint32_t msNum = Delay/1000;__IO uint32_t usNum = (uint32_t)((Delay%1000)*usDelayBase);if(msNum>0) HAL_Delay(msNum);delayReg = 0;while(delayReg!=usNum) delayReg++;
}
/* 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 ---------------------------------------------------------*/
UART_HandleTypeDef huart1;/* USER CODE BEGIN PV */
extern ApplicationTypeDef Appli_state; //UDISK available statusuint8_t uart1_rxd[256]; //Uart1 rx buffer
uint8_t uart1_txd[256]; //Uart1 tax buffer
uint8_t cmd; //Uart1 command indication
uint8_t ustatus = 0; //UDISK ready to operation indication (0: not ready; 1: ready)
uint8_t disk_mount_status = 0; //Disk fats mount status indication (0: unmount; 1: mount)
uint8_t FATS_Buff[_MAX_SS]; //Buffer for f_mkfs() operationFIL file; //File object for fats operation
UINT bytesread; //Byte number of read operation
UINT byteswritten;//Byte number of write operation
uint8_t rBuffer[20];      //Buffer for read
uint8_t WBuffer[20] ={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20}; //Buffer for write
/* USER CODE END PV *//* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART1_UART_Init(void);
void MX_USB_HOST_Process(void);/* USER CODE BEGIN PFP *//* USER CODE END PFP *//* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
#define LED_OFF HAL_GPIO_WritePin(GPIOC, GPIO_PIN_13, GPIO_PIN_SET)
#define LED_ON HAL_GPIO_WritePin(GPIOC, GPIO_PIN_13, GPIO_PIN_RESET)
#define LED_FLASH HAL_GPIO_TogglePin(GPIOC, GPIO_PIN_13)
/* USER CODE END 0 *//*** @brief  The application entry point.* @retval int*/
int main(void)
{/* USER CODE BEGIN 1 */FRESULT retUSB; //Operation return result statusdisk_mount_status = 0;uint32_t USB_Read_Size; //Read operation byte numberconst TCHAR* filepath = "0:test.txt"; //File partition number and name/* 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_FATFS_Init();MX_USB_HOST_Init();MX_USART1_UART_Init();/* USER CODE BEGIN 2 */PY_usDelayTest();PY_usDelayOptimize();HAL_UART_Receive_IT(&huart1, uart1_rxd, 1);/* USER CODE END 2 *//* Infinite loop *//* USER CODE BEGIN WHILE */while (1){/* USER CODE END WHILE */MX_USB_HOST_Process();/* USER CODE BEGIN 3 */if(Appli_state==APPLICATION_START){LED_FLASH;PY_Delay_us_t(500000);ustatus=0;}else if(Appli_state==APPLICATION_READY) //Status shift time from APPLICATION_START to APPLICATION_READY is about 90 second.{LED_ON;ustatus=1;}else{LED_OFF;ustatus = 0;}if(cmd>0){if(ustatus!=1){cmd = 0;printf("\r\nUSB disk not ready!\r\n");}else{if(cmd==0x01) //Mount USB{cmd = 0;if(disk_mount_status==1) printf("\r\nUSB mounted already\r\n");else{retUSB = f_mount(&USBHFatFS,(TCHAR const*)USBHPath,1); //SD mountif(retUSB==FR_NO_FILESYSTEM){printf("\r\nFile system doesn't exist. Now to format......\r\n");retUSB = f_mkfs((TCHAR const*)USBHPath, FM_FAT, 1024, FATS_Buff, sizeof(FATS_Buff)); //USB formatif(retUSB != FR_OK ){printf("\r\nFormat error: %d\r\n",retUSB);}else{printf("\r\nFormat OK\r\n");}}else if(retUSB==FR_OK){disk_mount_status = 1;printf("\r\nUSB mount successful\r\n");}else{printf("\r\nUSB mount error: %d\r\n",retUSB);}}}else if(cmd==2) //File creation and write{cmd = 0;if(disk_mount_status==0) printf("\r\nUSB not mounted: %d\r\n",retUSB);else{retUSB = f_open( &file, filepath, FA_CREATE_ALWAYS | FA_WRITE );  //Open or create fileif(retUSB == FR_OK){printf("\r\nFile open or creation successful\r\n");retUSB = f_write( &file, (const void *)WBuffer, sizeof(WBuffer), &byteswritten); //Write dataif(retUSB == FR_OK){printf("\r\nFile write successful\r\n");}else{printf("\r\nFile write error: %d\r\n",retUSB);}f_close(&file);   //Close file}else{printf("\r\nFile open or creation error %d\r\n",retUSB);}}}else if(cmd==3) //File read{cmd = 0;if(disk_mount_status==0) printf("\r\nUSB not mounted: %d\r\n",retUSB);else{retUSB = f_open( &file, filepath, FA_OPEN_EXISTING | FA_READ); //Open fileif(retUSB == FR_OK){printf("\r\nFile open successful\r\n");retUSB = f_read( &file, (void *)rBuffer, sizeof(rBuffer), &bytesread); //Read dataif(retUSB == FR_OK){printf("\r\nFile read successful\r\n");PY_Delay_us_t(200000);USB_Read_Size = sizeof(rBuffer);for(uint16_t i = 0;i < USB_Read_Size;i++){printf("%d ", rBuffer[i]);}printf("\r\n");}else{printf("\r\nFile read error: %d\r\n", retUSB);}f_close(&file); //Close file}else{printf("\r\nFile open error: %d\r\n", retUSB);}}}else if(cmd==4) //File locating write{cmd = 0;if(disk_mount_status==0) printf("\r\nUSB not mounted: %d\r\n",retUSB);else{retUSB = f_open( &file, filepath, FA_CREATE_ALWAYS | FA_WRITE);  //Open or create fileif(retUSB == FR_OK){printf("\r\nFile open or creation successful\r\n");retUSB=f_lseek( &file, f_tell(&file) + sizeof(WBuffer) ); //move file operation pointer, f_tell(&file) gets file head locatingif(retUSB == FR_OK){retUSB = f_write( &file, (const void *)WBuffer, sizeof(WBuffer), &byteswritten);if(retUSB == FR_OK){printf("\r\nFile locating write successful\r\n");}else{printf("\r\nFile locating write error: %d\r\n", retUSB);}}else{printf("\r\nFile pointer error: %d\r\n",retUSB);}f_close(&file);   //Close file}else{printf("\r\nFile open or creation error %d\r\n",retUSB);}}}else if(cmd==5) //File locating read{cmd = 0;if(disk_mount_status==0) printf("\r\nUSB not mounted: %d\r\n",retUSB);else{retUSB = f_open(&file, filepath, FA_OPEN_EXISTING | FA_READ); //Open fileif(retUSB == FR_OK){printf("\r\nFile open successful\r\n");retUSB =  f_lseek(&file,f_tell(&file)+ sizeof(WBuffer)/2); //move file operation pointer, f_tell(&file) gets file head locatingif(retUSB == FR_OK){retUSB = f_read( &file, (void *)rBuffer, sizeof(rBuffer), &bytesread);if(retUSB == FR_OK){printf("\r\nFile locating read successful\r\n");PY_Delay_us_t(200000);USB_Read_Size = sizeof(rBuffer);for(uint16_t i = 0;i < USB_Read_Size;i++){printf("%d ",rBuffer[i]);}printf("\r\n");}else{printf("\r\nFile locating read error: %d\r\n",retUSB);}}else{printf("\r\nFile pointer error: %d\r\n",retUSB);}f_close(&file);}else{printf("\r\nFile open error: %d\r\n",retUSB);}}}else;}}}/* 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_RCC_PWR_CLK_ENABLE();__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);/** 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 = 25;RCC_OscInitStruct.PLL.PLLN = 336;RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;RCC_OscInitStruct.PLL.PLLQ = 7;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_DIV2;RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK){Error_Handler();}
}/*** @brief USART1 Initialization Function* @param None* @retval None*/
static void MX_USART1_UART_Init(void)
{/* USER CODE BEGIN USART1_Init 0 *//* USER CODE END USART1_Init 0 *//* USER CODE BEGIN USART1_Init 1 *//* USER CODE END USART1_Init 1 */huart1.Instance = USART1;huart1.Init.BaudRate = 115200;huart1.Init.WordLength = UART_WORDLENGTH_8B;huart1.Init.StopBits = UART_STOPBITS_1;huart1.Init.Parity = UART_PARITY_NONE;huart1.Init.Mode = UART_MODE_TX_RX;huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;huart1.Init.OverSampling = UART_OVERSAMPLING_16;if (HAL_UART_Init(&huart1) != HAL_OK){Error_Handler();}/* USER CODE BEGIN USART1_Init 2 *//* USER CODE END USART1_Init 2 */}/*** @brief GPIO Initialization Function* @param None* @retval None*/
static void MX_GPIO_Init(void)
{GPIO_InitTypeDef GPIO_InitStruct = {0};/* GPIO Ports Clock Enable */__HAL_RCC_GPIOC_CLK_ENABLE();__HAL_RCC_GPIOH_CLK_ENABLE();__HAL_RCC_GPIOA_CLK_ENABLE();/*Configure GPIO pin Output Level */HAL_GPIO_WritePin(GPIOC, GPIO_PIN_13, GPIO_PIN_RESET);/*Configure GPIO pin Output Level */HAL_GPIO_WritePin(GPIOA, GPIO_PIN_8, GPIO_PIN_RESET);/*Configure GPIO pin : PC13 */GPIO_InitStruct.Pin = GPIO_PIN_13;GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;GPIO_InitStruct.Pull = GPIO_NOPULL;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);/*Configure GPIO pin : PA8 */GPIO_InitStruct.Pin = GPIO_PIN_8;GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;GPIO_InitStruct.Pull = GPIO_NOPULL;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);}/* USER CODE BEGIN 4 */
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{if(huart==&huart1){cmd = uart1_rxd[0];HAL_UART_Receive_IT(&huart1, uart1_rxd, 1);}
}
/* USER CODE END 4 *//*** @brief  Period elapsed callback in non blocking mode* @note   This function is called  when TIM1 interrupt took place, inside* HAL_TIM_IRQHandler(). It makes a direct call to HAL_IncTick() to increment* a global variable "uwTick" used as application time base.* @param  htim : TIM handle* @retval None*/
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{/* USER CODE BEGIN Callback 0 *//* USER CODE END Callback 0 */if (htim->Instance == TIM1) {HAL_IncTick();}/* USER CODE BEGIN Callback 1 *//* USER CODE END Callback 1 */
}/*** @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 */

注意其中的f_mkfs格式化U盘库函数在不同的库版本参数数量不一样，上面范例是参数较多的版本，根据实际库函数调整即可。

STM32例程测试

串口指令0x01测试效果如下：

串口指令0x02测试效果如下：

串口指令0x03测试效果如下：

串口指令0x04测试效果如下：

串口指令0x05测试效果如下：

注意事项

STM32从识别U盘连接到可操作状态准备好时间比较长，实测约90秒
STM32做U盘容量识别时间也比较长，实测4GB U盘容量识别时间达到3~4分钟。

STM32例程下载

STM32F401CCU6 USB接口FATS文件读写U盘例程下载

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