[STM32F4xx] I2C Device Address 찾기

오늘 보안관련 칩 회사에서 I2C I/F 로 된 IC를 받았는데,

I2C Address 도 보안인가 봅니다. ㅠㅠ

저한테는 분명히 Device Address 가 0x7A 라고 해서, 아무리 해도 안되서,

보안(이게 보안이냐?, Device Address 를 찾아내는 작업)을 뚫어 봤습니다. ^^

원리는 I2C 칩은 항상 Device Address 를 보내서 해당 Address가 맞으면,  ACK를 보냅니다.

STM32Fx 의 I2C Tx 인터럽트는 

ACK를 받으면    인터럽트 콜백 함수를 호출하고,

ACK를 못 받으면 인터럽트 콜백 함수를 호출하지 않습니다.

그리고 주소는 7비트이므로, 0x00~0x7F 범위에 있습니다.

이 원리를 이용해서, 0x00~0x7F 범위의 Device Address를 1개씩 보내고 조금 기다리다 ACK 안오면,

다시 Device Address를 1개씩 보내고를 반복 하다보면 ACK가 오는 경우가 바로 이 칩의 Device Address 입니다.

다음 번에 I2C 에 대해서 다시 자세히 설명할 것이라 간단하게 어드레스 찾는 함수 쪽하고 콜백함수만 적어 봅니다.

Tx 콜백 함수 내용

void HAL_I2C_MasterTxCpltCallback(I2C_HandleTypeDef *hi2c)
{
    f_add_cmpl = 1;
    printf("Tx compleate~!!\r\n");
}

Device address 찾는 함수.

void I2C_Add_serch(void)
{
    uint8_t i;
    for(i=0;i<0x80;i++)
    {
        f_add_cmpl=0;
        HAL_I2C_Master_Transmit_DMA(&hi2c1,(uint16_t)(i<<1),i2c_wr_buff,1);
        HAL_Delay(10);    
        if (f_add_cmpl == 1)
        {
            printf("Device Address search complete. [%02X]\r\n",i);
            return;
        }
    }
    printf("Device Address search fail.\r\n");
}

이 두개의 함수와 printf() 함수 사용하는 내용 외에는 CUBEMX가 자동으로 만들어 준 것을 썼는데,

몇 줄 안되네요. ^^

이 방법으로 찾은 어드레스는 0x3D 였습니다. 1초도 안걸립니다. ^^

다음은 보안칩 에 잘못된 주소의 응답과 맞게 입력한 주소의 파형입니다.

다음은 전체 소스 입니다. DMA를 사용해 봤습니다. 자세한 내용은 다음에 ..

/**
  ******************************************************************************
  * File Name          : main.c
  * Description        : Main program body
  ******************************************************************************
  ** This notice applies to any and all portions of this file
  * that are not between comment pairs USER CODE BEGIN and
  * USER CODE END. Other portions of this file, whether 
  * inserted by the user or by software development tools
  * are owned by their respective copyright owners.
  *
  * COPYRIGHT(c) 2017 STMicroelectronics
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *   1. Redistributions of source code must retain the above copyright notice,
  *      this list of conditions and the following disclaimer.
  *   2. Redistributions in binary form must reproduce the above copyright notice,
  *      this list of conditions and the following disclaimer in the documentation
  *      and/or other materials provided with the distribution.
  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
  *      without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  */
 
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "stm32f4xx_hal.h"
 
/* USER CODE BEGIN Includes */
#include "string.h"
/* USER CODE END Includes */
 
/* Private variables ---------------------------------------------------------*/
I2C_HandleTypeDef hi2c1;
DMA_HandleTypeDef hdma_i2c1_tx;
DMA_HandleTypeDef hdma_i2c1_rx;
 
UART_HandleTypeDef huart2;
 
/* USER CODE BEGIN PV */
/* Private variables ---------------------------------------------------------*/
uint8_t f_add_cmpl=0;
uint8_t i2c_wr_buff[20];
 
/* USER CODE END PV */
 
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_USART2_UART_Init(void);
static void MX_I2C1_Init(void);
 
/* USER CODE BEGIN PFP */
/* Private function prototypes -----------------------------------------------*/
 
/* USER CODE END PFP */
 
/* USER CODE BEGIN 0 */
#ifdef __GNUC__
 #define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
 #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif
 
PUTCHAR_PROTOTYPE
{
 HAL_UART_Transmit(&huart2, (uint8_t *)&ch, 1, 1);
 return ch;
}
 
void HAL_I2C_MasterTxCpltCallback(I2C_HandleTypeDef *hi2c)
{
    f_add_cmpl = 1;
    printf("Tx compleate~!!\r\n");
}
 
void HAL_I2C_MasterRxCpltCallback(I2C_HandleTypeDef *hi2c)
{
}
 
void I2C_Add_serch(void)
{
    uint8_t i;
    for(i=0;i<0x80;i++)
    {
        f_add_cmpl=0;
        HAL_I2C_Master_Transmit_DMA(&hi2c1,(uint16_t)(i<<1),i2c_wr_buff,1);
        HAL_Delay(10);    
        if (f_add_cmpl == 1)
        {
            printf("Device Address search complete. [%02X]\r\n",i);
            return;
        }
    }
    printf("Device Address search fail.\r\n");
}
/* USER CODE END 0 */
 
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_DMA_Init();
  MX_USART2_UART_Init();
  MX_I2C1_Init();
 
  /* USER CODE BEGIN 2 */
    I2C_Add_serch();
  /* USER CODE END 2 */
 
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while(1)
  {
  /* USER CODE END WHILE */
 
  /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
 
}
 
/** System Clock Configuration
*/
void SystemClock_Config(void)
{
 
  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
 
    /**Configure the main internal regulator output voltage 
    */
  __HAL_RCC_PWR_CLK_ENABLE();
 
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
 
    /**Initializes the CPU, AHB and APB busses clocks 
    */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 4;
  RCC_OscInitStruct.PLL.PLLN = 100;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 4;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }
 
    /**Initializes the CPU, AHB and APB busses 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_3) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }
 
    /**Configure the Systick interrupt time 
    */
  HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);
 
    /**Configure the Systick 
    */
  HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
 
  /* SysTick_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
}
 
/* I2C1 init function */
static void MX_I2C1_Init(void)
{
 
  hi2c1.Instance = I2C1;
  hi2c1.Init.ClockSpeed = 50000;
  hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
  hi2c1.Init.OwnAddress1 = 244;
  hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
  hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
  hi2c1.Init.OwnAddress2 = 0;
  hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
  hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
  if (HAL_I2C_Init(&hi2c1) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }
 
}
 
/* USART2 init function */
static void MX_USART2_UART_Init(void)
{
 
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart2) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }
 
}
 
/** 
  * Enable DMA controller clock
  */
static void MX_DMA_Init(void) 
{
  /* DMA controller clock enable */
  __HAL_RCC_DMA1_CLK_ENABLE();
 
  /* DMA interrupt init */
  /* DMA1_Stream0_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA1_Stream0_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream0_IRQn);
  /* DMA1_Stream1_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA1_Stream1_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream1_IRQn);
 
}
 
/** Configure pins as 
        * Analog 
        * Input 
        * Output
        * EVENT_OUT
        * EXTI
*/
static void MX_GPIO_Init(void)
{
 
  GPIO_InitTypeDef GPIO_InitStruct;
 
  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOH_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();
 
  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(LD2_GPIO_Port, LD2_Pin, GPIO_PIN_RESET);
 
  /*Configure GPIO pin : B1_Pin */
  GPIO_InitStruct.Pin = B1_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_FALLING;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(B1_GPIO_Port, &GPIO_InitStruct);
 
  /*Configure GPIO pin : LD2_Pin */
  GPIO_InitStruct.Pin = LD2_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(LD2_GPIO_Port, &GPIO_InitStruct);
 
}
 
/* USER CODE BEGIN 4 */
 
/* USER CODE END 4 */
 
/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
void _Error_Handler(char * file, int line)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */
  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
 
/**
  * @}
  */ 
 
/**
  * @}
*/ 
 
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

i2c_test.ioc