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I2C with LPC2387

Dhaval Shah

Hi,

I am working on MCB2300(LPC2387).
I have used its sample code for Temperature sensing using I2C and its working fine.
Now I have connected EEPROM (AT24C02) with microcontroller to store some data.
For that I have used same code and did some changes to write and read data from EEPROM.
But its not working properly.
Below is changes which I have done.

int main (void)
{
  DWORD i;

  if ( I2CInit( (DWORD)I2CMASTER ) == FALSE )   /* initialize I2c */
  {
        while ( 1 );                            /* Fatal error */
  }

  /* Configure temp register before reading */
  for ( i = 0; i < BUFSIZE; i++ )    /* clear buffer */
  {
        I2CMasterBuffer[i] = 0;
  }
  I2CWriteLength = 3;
  I2CReadLength = 0;
  I2CMasterBuffer[0] = 0xA0;
  I2CMasterBuffer[1] = 0x00;
  I2CMasterBuffer[2] = 0x10;    /* configuration value, no change from
                                                                default */
  I2CCmd = LM75_CONFIG;
  I2CEngine();

   for ( i = 0; i < BUFSIZE; i++ )   /* clear buffer */
  {
        I2CMasterBuffer[i] = 0;
  }

  I2CWriteLength = 2;
  I2CReadLength = 1;
  I2CMasterBuffer[0] = 0xA1;
  I2CMasterBuffer[1] = 0x00;
  I2CCmd = 0xA0;
  I2CEngine();
  }

Suggest me where I have done mistake.
any link of tutorial for R/W data using LPC2387 will be appreciated.
Hope for best solution.

Thanks
Dhaval

  • 0

    "But its not working properly."

    I think if you change your code, it will work properly.

  • 0

    Based on my experience of LPC2368 with AT24LC64, you need to re-write the Interrupt Handler of I2C.

    void I2C0MasterHandler(void) __irq
{
  BYTE StatValue;

  /* this handler deals with master read and master write only */
  StatValue = I20STAT;

  // App should clear buffer, not ISR.
  switch ( StatValue )
  {
        case 0x08:    // Master Transmitter mode; Master Receiver mode;
        // A START condition has been transmitted.
                break;

        case 0x10:    // Master Transmitter mode; Master Receiver mode;
        // A repeated START condition has been transmitted.
                break;

        case 0x18:    // Master Transmitter mode;
        // SLA+W has been transmitted; ACK has been received.
                break;

        case 0x28:    // Master Transmitter mode;
        // Data byte in I2DAT has been transmitted; ACK has been received.
                if (!Dummy_Write)
                {
                        if ( DatBuf_Idx < I2C_BUFSIZE )
                        {
                          DatBuf_Idx++;
                        }
                        else
                        {
                          DatBuf_Idx = 0;
                        }
                }
                else
                {
                }
                break;

        case 0x40:    // Master Receiver mode;
        // SLA+R has been transmitted; ACK has been received.
                break;

        case 0x50:    // Master Receiver mode;
        // Data byte has been received; ACK has been returned.
                DatBuf_Idx++;
                if ( DatBuf_Idx >= (I2C_BUFSIZE-1) )
                {
                }
                break;

        case 0x58:    // Master Receiver mode;
        // Data byte has been received; NOT ACK has been returned.
                break;

        /* Do NOT need-want to Handle. */
        case 0x20:    // Master Transmitter mode;
        case 0x30:    // Master Transmitter mode;
        case 0x38:    // Master Transmitter mode; Master Receiver mode;
        case 0x48:    // Master Receiver mode;

        default:
                I2CMasterState = DATA_ERROR;
                I20CONCLR = I2CONCLR_SIC;
                break;
  }

  VICVectAddr = 0;              /* Acknowledge Interrupt */
}

  • 0 in reply to John Linq

    ics.nxp.com/.../lpc17xx.cmsis.driver.library.zip

    Download the above driver library, it is for LPC17xx, but the I2C controller supposed to be similar.

    Now, NXP provides more I2C examples, including:

    /***********************************************************************//**
 * @file                pca8581_test.c
 * @purpose             An example of I2C using polling mode to test the I2C driver.
 *                              Using EEPROM PCA8581 to transfer a number of data byte.
 * @version             2.0
 * @date                21. May. 2010
 * @author              NXP MCU SW Application Team
 *---------------------------------------------------------------------

    The path:
    lpc17xx.cmsis.driver.library\LPC1700CMSIS\Examples\I2C\pca8581_polling

  • 0 in reply to John Linq

    "void I2C0MasterHandler(void) __irq"

    that's the worst aspect of the lpc i2c engine.

    it runs off a series of "states", rather than a series of tasks (i2c_start, i2c_send, i2c_read, i2c_stop, etc.).

    not sure why nxp decided to do it that way.

  • 0 in reply to Ashley Madison

    Sounds similar to the STM32's I2C...

  • 0 in reply to Andy Neil

    "Sounds similar to the STM32's I2C..."

    maybe you are looking at different stm32s, :)

    here is from the st library for stm32:

    void I2C_Init(I2C_TypeDef* I2Cx, I2C_InitTypeDef* I2C_InitStruct);
void I2C_GenerateSTART(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_GenerateSTOP(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_AcknowledgeConfig(I2C_TypeDef* I2Cx, FunctionalState NewState);
void I2C_Send7bitAddress(I2C_TypeDef* I2Cx, uint8_t Address, uint8_t I2C_Direction);
void I2C_SendData(I2C_TypeDef* I2Cx, uint8_t Data);
uint8_t I2C_ReceiveData(I2C_TypeDef* I2Cx);

    does it look like they are even remotely similar to the lpc code?