FlorianFrank/stm32_usb_lib

Library to access USB mass storage devices from STM32 boards.

STM32_USB_Lib

A Library which allows to read and write to USB masstorage devices from STM32 boards. This library was tested with an STM32F429-DISK1 evaluation board.

Installation

1. Checkout the repository and build the library

    git clone git@github.com:FlorianFrank/STM32_USB_Lib.git
    cd stm32_usb_lib
    ./build.sh

2. Link library to an STM32 project

• 2.1 Copy the library from stm32_usb_lib/lib/ to the linking location (e.g. /lib)
• 2.3 Add the files usb_defines.h and usb_handler.h to the STM32 project
• 2.3 Open the project settings in STM32 cube IDE, specify the linking location and link the library

3. Adjust the SystemClock settings

Activate PLL and set HSI (16 MHz RC oscillator) as clock source inside the main.c-file.

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_SCALE3);
  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */

  	  /* Enable HSE Oscillator and activate PLL with HSE as source */
  	  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_HSI;
  	  RCC_OscInitStruct.PLL.PLLM = 8;
  	  RCC_OscInitStruct.PLL.PLLN = 336;
  	  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  	  RCC_OscInitStruct.PLL.PLLQ = 7;
  	  HAL_RCC_OscConfig (&RCC_OscInitStruct);

  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
}

4. Programming example

#include "usb_handler.h"

USB_MS_Handle usbHandle;
USB_ERROR retInit = { USB_TIMEOUT, 0};

// Init USB communication
retInit = USB_InitConnection(&usbHandle);
if(retInt.m_ErrCode != USB_NO_ERROR)
    USB_ReturnErrorCodeStr(retInit)

// Wait until USB device is detected
USB_ERROR ret = { USB_TIMEOUT, 0};
do
{
    ret = USB_ExecuteStateMachine(&usbHandle, 1000);
    if(ret.m_ErrCode != USB_NO_ERROR && ret.m_ErrCode != USB_TIMEOUT)
        USB_ReturnErrorCodeStr(ret)
}while(ret.m_ErrCode != USB_NO_ERROR);

// Create or overwrite new file Test.txt on the connected masstorage device
uint32_t len = strlen("Hallo Welt!");
ret = USB_OpenWriteFile(&usbHandle, "Test.txt", (uint8_t*)"Hallo Welt!", &len, USB_OVERWRITE | USB_WRITE, FALSE);
if(ret.m_ErrCode != USB_NO_ERROR)
    USB_ReturnErrorCodeStr(ret)

// Append to an existing file and write continously
ret = USB_OpenFile(&usbHandle, "LogFile.txt", USB_APPEND | USB_WRITE);
if(ret.m_ErrCode != USB_NO_ERROR)
    USB_ReturnErrorCodeStr(ret)

uint8_t buffer[10];
memset(buffer, 0x55, 10);
uint32_t bufferLen = 10;

for(int i = 0; i < 10; i++)
{
    ret = USB_WriteData(&usbHandle, buffer, &bufferLen, true);
    if(ret.m_ErrCode != USB_NO_ERROR)
        USB_ReturnErrorCodeStr(ret)

    printf("Amount of data written %d\n", bufferLen):
}
USB_CloseFile(&usbHandle);