C++ (Cpp) I2C_IF_Read Examples

Example #1

File: pwm_break_out_if.c Project: brandonto/Human_Interface_for_Robotic_Control

//****************************************************************************
//
//! Read an 8 bit data from a register on the PWM board
//!
//! \param  regAddress: register's address
//
//!  \return 8 bit data
//****************************************************************************
static uint8_t read(uint8_t regAddress) 
{
    int iRetVal;
    unsigned char DataBuf[1];
    //Construct the data buffer
    DataBuf[0] = (unsigned char) regAddress;
    //Send command to the PWM board
    iRetVal = I2C_IF_Write((unsigned char)PWM_ADDRESS, DataBuf, 1, 1);
    if(iRetVal == FAILURE)
    {
        #ifdef PWM_DEBUG
        UART_PRINT("I2C Read failed\n\r");
        #endif
        return 0; // TODO: figure out error code, use 0 as temp
    }
    //Read the value from the register
    iRetVal = I2C_IF_Read((unsigned char)PWM_ADDRESS, DataBuf, 1);
    if(iRetVal == SUCCESS)
    {
        #ifdef PWM_DEBUG
        //UART_PRINT("I2C Read complete\n\r");
        #endif 
        return ((uint8_t)DataBuf[0]);
    }
    else
    {
        #ifdef PWM_DEBUG
        UART_PRINT("I2C Read failed\n\r");
        #endif
        return 0;// TODO: figure out error code, use 0 as temp
    }
}

Example #2

File: HDC1050.cpp Project: alashworth/cc3200-sensor

int HDC1050::get_tempature_and_humidity(HDC1050::reading &measurement) {
    // execute pointer write transaction at 0x00
    int rc = I2C_IF_Write(DEVICE_ADDRESS,0 /* device address*/, 1 /* bytes to read */, 0 /*no stop bit */);

    // wait at least 6.5 milliseconds - every 1000 ticks is 12.5 us
    MAP_UtilsDelay(10000000);

    static uint8_t temperature[2];
    static uint8_t humidity[2];

    uint32_t temp = 0;
    uint32_t hum = 0;

    // read
    I2C_IF_Read(DEVICE_ADDRESS + Registers8::temperature, &temperature[0], 2);
    I2C_IF_Read(DEVICE_ADDRESS + Registers8::humidity , &humidity[0], 2);

    // process readings
    temp = temperature[1];
    temp = temp << 4;
    temp += temperature[0];

    temp = temp * 165 - 40;
    temp = temp << 16;

    measurement.temperature = temp;  // celsius

    hum = humidity[1];
    hum *= 100;
    hum = hum << 16;

    measurement.humidity = hum;  // relative humidty as percentage

    // todo: check for nack
    return 0;
}

Example #3

File: main.c Project: Balu1991/Wifly_Light

//****************************************************************************
//
//! Parses the readreg command parameters and invokes the I2C APIs
//! i2c readreg 0x<dev_addr> 0x<reg_offset> <rdlen>
//!
//! \param pcInpString pointer to the readreg command parameters
//! 
//! This function  
//!    1. Parses the readreg command parameters.
//!    2. Invokes the corresponding I2C APIs
//!
//! \return 0: Success, < 0: Failure.
//
//****************************************************************************
int
ProcessReadRegCommand(char *pcInpString)
{
    unsigned char ucDevAddr, ucRegOffset, ucRdLen;
    unsigned char aucRdDataBuf[256];
    char *pcErrPtr;

    //
    // Get the device address
    //
    pcInpString = strtok(NULL, " ");
    RETERR_IF_TRUE(pcInpString == NULL);
    ucDevAddr = (unsigned char)strtoul(pcInpString+2, &pcErrPtr, 16);
    //
    // Get the register offset address
    //
    pcInpString = strtok(NULL, " ");
    RETERR_IF_TRUE(pcInpString == NULL);
    ucRegOffset = (unsigned char)strtoul(pcInpString+2, &pcErrPtr, 16);

    //
    // Get the length of data to be read
    //
    pcInpString = strtok(NULL, " ");
    RETERR_IF_TRUE(pcInpString == NULL);
    ucRdLen = (unsigned char)strtoul(pcInpString, &pcErrPtr, 10);
    //RETERR_IF_TRUE(ucLen > sizeof(aucDataBuf));

    //
    // Write the register address to be read from.
    // Stop bit implicitly assumed to be 0.
    //
    RET_IF_ERR(I2C_IF_Write(ucDevAddr,&ucRegOffset,1,0));
    
    //
    // Read the specified length of data
    //
    RET_IF_ERR(I2C_IF_Read(ucDevAddr, &aucRdDataBuf[0], ucRdLen));

    UART_PRINT("I2C Read From address complete\n\r");
    
    //
    // Display the buffer over UART on successful readreg
    //
    DisplayBuffer(aucRdDataBuf, ucRdLen);

    return SUCCESS;
}

Example #4

File: main.c Project: Balu1991/Wifly_Light

//****************************************************************************
//
//! Parses the read command parameters and invokes the I2C APIs
//!
//! \param pcInpString pointer to the user command parameters
//! 
//! This function  
//!    1. Parses the read command parameters.
//!    2. Invokes the corresponding I2C APIs
//!
//! \return 0: Success, < 0: Failure.
//
//****************************************************************************
int
ProcessReadCommand(char *pcInpString)
{
    unsigned char ucDevAddr, ucLen;
    unsigned char aucDataBuf[256];
    char *pcErrPtr;
    int iRetVal;

    //
    // Get the device address
    //
    pcInpString = strtok(NULL, " ");
    RETERR_IF_TRUE(pcInpString == NULL);
    ucDevAddr = (unsigned char)strtoul(pcInpString+2, &pcErrPtr, 16);
    //
    // Get the length of data to be read
    //
    pcInpString = strtok(NULL, " ");
    RETERR_IF_TRUE(pcInpString == NULL);
    ucLen = (unsigned char)strtoul(pcInpString, &pcErrPtr, 10);
    //RETERR_IF_TRUE(ucLen > sizeof(aucDataBuf));
    
    //
    // Read the specified length of data
    //
    iRetVal = I2C_IF_Read(ucDevAddr, aucDataBuf, ucLen);

    if(iRetVal == SUCCESS)
    {
        UART_PRINT("I2C Read complete\n\r");
        
        //
        // Display the buffer over UART on successful write
        //
        DisplayBuffer(aucDataBuf, ucLen);
    }
    else
    {
        UART_PRINT("I2C Read failed\n\r");
        return FAILURE;
    }

    return SUCCESS;
}