STM32L0C8T6 failed to communicate with M24C02 through IIC

[*于.1]

STM32L0C8T6 failed to communicate with M24C02 through IIC，iic uses cubemx default configuration，The relevant code show as below：

#define ADDR_24LCxx_Write 0xA0

#define ADDR_24LCxx_Read 0xA1

#define IIC_BufferSize 256

uint8_t IIC_WriteBuffer[IIC_BufferSize],IIC_ReadBuffer[IIC_BufferSize];

uint8_t IIC_flag = 0;

HAL_GPIO_WritePin(GPIOB, GPIO_PIN_9, GPIO_PIN_SET);  //eeprom power on

​IIC_WriteBuffer[0] = 0x01;

IIC_WriteBuffer[1] = 0x02;

IIC_flag = HAL_I2C_Mem_Write(&hi2c1, ADDR_24LCxx_Write, 0, I2C_MEMADD_SIZE_8BIT,IIC_WriteBuffer,8, 1000);

if(IIC_flag == HAL_OK)

{

sprintf(string,"IIC write succeed!\r\n"); 

HAL_UART_Transmit(&huart1,(uint8_t*)string,strlen((char *)string),1000);

}

else

{

sprintf(string,"IIC write falsed!IIC_flag: %d\r\n",IIC_flag); 

HAL_UART_Transmit(&huart1,(uint8_t*)string,strlen((char *)string),1000);

}

Online debugging code stops here：

  /* Send Slave Address and Memory Address */

  if (I2C_RequestMemoryWrite(hi2c, DevAddress, MemAddress, MemAddSize, Timeout, tickstart) != HAL_OK)

  {

   if (hi2c->ErrorCode == HAL_I2C_ERROR_AF)

   {

    /* Process Unlocked */

    __HAL_UNLOCK(hi2c);

    return HAL_ERROR;

   }

   else

   {

    /* Process Unlocked */

    __HAL_UNLOCK(hi2c);

    return HAL_TIMEOUT;

   }

  }

sch：

​

[Peter BENSCH]

Please add a few milliseconds delay after switching on the EEPROM, like:

HAL_GPIO_WritePin(GPIOB, GPIO_PIN_9, GPIO_PIN_SET);  //eeprom power on
HAL_Delay(10);
IIC_WriteBuffer[0] = 0x01;

What frequency do you set the I2C clock to?

BTW: to make the source code more readable, please use the </> button to include it.

Regards

/Peter

[AIM65]

In addition with the startup delay recommanded in the previous post; usually, with I2C memory device, more when they're as old as an 24C02, one should check if device is ready before any read or write operation, HAL propose this feature : HAL_I2C_IsDeviceReady(). Example code :

//Read one or several byte from EEPROM

void EEPROM_RD(uint16_t Addr, uint16_t nbyte, uint8_t* pdata)

{

if (HAL_I2C_IsDeviceReady(&hi2c1, EEPROM_BASEADDR, I2CRETRY, I2CXTIMEOUT)!= HAL_OK) I2Cx_Error();

if (HAL_I2C_Mem_Read(&hi2c1, EEPROM_BASEADDR, Addr, I2C_MEMADD_SIZE_16BIT,pdata, nbyte, I2CXTIMEOUT) != HAL_OK) I2Cx_Error();

}

Number of retry and timeout duration could be high for safe operation with old device, for example :

#define I2CXTIMEOUT 20 //20ms

#define I2CRETRY 80

with a 64MHz f030 MPU and a 24c16.