基于HAL库的STM32F4 I2C驱动的示例代码，可以读写两个PCA9555芯片，并且具有读写容错功能与操作PCA9555输出PIN脚电平功能。如果出现错误，代码将重新初始化PCA9555芯片

以下是基于HAL库的STM32F4 I2C驱动的示例代码，可以读写两个PCA9555芯片，并且具有读写容错功能与操作PCA9555输出PIN脚电平功能。如果出现错误，代码将重新初始化PCA9555芯片。

#include "stm32f4xx_hal.h"

#define PCA9555_ADDRESS_1 0x40   // I2C address of PCA9555 #1
#define PCA9555_ADDRESS_2 0x41   // I2C address of PCA9555 #2

#define PCA9555_INPUT_PORT_0 0x00    // Input port register address of PCA9555
#define PCA9555_OUTPUT_PORT_0 0x02   // Output port register address of PCA9555
#define PCA9555_CONFIG_PORT_0 0x06   // Configuration port register address of PCA9555

I2C_HandleTypeDef hi2c1;   // I2C handle

// Function prototypes
void I2C_Init(void);
void PCA9555_Init(uint8_t address);
void PCA9555_WritePin(uint8_t address, uint8_t pin, uint8_t value);
uint8_t PCA9555_ReadPin(uint8_t address, uint8_t pin);
void PCA9555_RetryInit(uint8_t address);

int main(void)
{
  HAL_Init();
  I2C_Init();

  PCA9555_Init(PCA9555_ADDRESS_1);
  PCA9555_Init(PCA9555_ADDRESS_2);

  while (1)
  {
    // Read the state of pin 0 on PCA9555 #1
    uint8_t state = PCA9555_ReadPin(PCA9555_ADDRESS_1, 0);
    if (state == 0)
    {
      // If pin 0 is low, set pin 1 on PCA9555 #2 to high
      PCA9555_WritePin(PCA9555_ADDRESS_2, 1, 1);
    }
    else
    {
      // If pin 0 is high, set pin 1 on PCA9555 #2 to low
      PCA9555_WritePin(PCA9555_ADDRESS_2, 1, 0);
    }

    HAL_Delay(100);   // Delay for 100ms
  }
}

// Initialize the I2C peripheral
void I2C_Init(void)
{
  hi2c1.Instance = I2C1;
  hi2c1.Init.ClockSpeed = 100000;
  hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
  hi2c1.Init.OwnAddress1 = 0;
  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();
  }
}

// Initialize the PCA9555 at the specified address
void PCA9555_Init(uint8_t address)
{
  // Initialize the configuration port to set all pins as outputs
  uint8_t config = 0x00;
  HAL_I2C_Mem_Write(&hi2c1, address, PCA9555_CONFIG_PORT_0, 1, &config, 1, 100);

  // Initialize the output port to set all pins to low
  uint8_t output = 0x00;
  HAL_I2C_Mem_Write(&hi2c1, address, PCA9555_OUTPUT_PORT_0, 1, &output, 1, 100);
}

// Write the specified value to the specified pin on the PCA9555 at the specified address
void PCA9555_WritePin(uint8_t address, uint8_t pin, uint8_t value)
{
  uint8_t output = 0x00;
  HAL_I2C_Mem_Read(&hi2c1, address, PCA9555_OUTPUT_PORT_0, 1, &output, 1, 100);

  // Set the specified pin to the specified value
  if (value == 0)
  {
    output &= ~(1 << pin);
  }
  else
  {
    output |= (1 << pin);
  }

  // Write the updated output value to the PCA9555
  uint8_t data[2] = { PCA9555_OUTPUT_PORT_0, output };
  if (HAL_I2C_Master_Transmit(&hi2c1, address, data, 2, 100) != HAL_OK)
  {
    // If there is an error, retry initializing the PCA9555
    PCA9555_RetryInit(address);
  }
}

// Read the state of the specified pin on the PCA9555 at the specified address
uint8_t PCA9555_ReadPin(uint8_t address, uint8_t pin)
{
  uint8_t input = 0x00;
  if (HAL_I2C_Mem_Read(&hi2c1, address, PCA9555_INPUT_PORT_0, 1, &input, 1, 100) != HAL_OK)
  {
    // If there is an error, retry initializing the PCA9555
    PCA9555_RetryInit(address);
    return 0;
  }

  return (input >> pin) & 0x01;
}

// Retry initializing the PCA9555 at the specified address
void PCA9555_RetryInit(uint8_t address)
{
  // Clear the I2C error flags and reset the I2C peripheral
  __HAL_I2C_CLEAR_FLAG(&hi2c1, I2C_FLAG_AF | I2C_FLAG_ARLO | I2C_FLAG_BERR);
  HAL_I2C_DeInit(&hi2c1);
  HAL_Delay(100);
  HAL_I2C_Init(&hi2c1);

  // Re-initialize the PCA9555
  PCA9555_Init(address);
}

这段代码中，需要注意以下几个点：

- 在 `I2C_Init()` 函数中初始化了 I2C1 的参数，并初始化了 I2C 外设。
- `PCA9555_Init()` 函数用于初始化 PCA9555 芯片。首先将配置端口全部设置为输出模式，然后将输出端口全部设置为低电平。
- `PCA9555_WritePin()` 函数用于向 PCA9555 芯片的指定引脚写入指定值。函数首先读取当前输出状态，然后根据参数设置需要修改的引脚状态，最后将更新后的输出状态写入 PCA9555 芯片。如果写入过程中发生错误，函数会调用 `PCA9555_RetryInit()` 函数重新初始化 PCA9555 芯片。
- `PCA9555_ReadPin()` 函数用于读取 PCA9555 芯片的指定引脚状态。函数首先读取输入状态，并根据参数返回指定引脚的状态。如果读取过程中发生错误，函数会调用 `PCA9555_RetryInit()` 函数重新初始化 PCA9555 芯片。
- `PCA9555_RetryInit()` 函数用于重新初始化 PCA9555 芯片。函数首先清除外设的 I2C 错误标志，并重置 I2C 外设。然后调用 `PCA9555_Init()` 函数重新初始化 PCA9555 芯片。