TMS570LC4357-EP: I2C Problems When Interfacing With HTU21D Temp/Humidity Sensor

/** @file sys_main.c 
*   @brief Application main file
*   @date 28.Aug.2015
*   @version 04.05.01
*
*   This file contains an empty main function,
*   which can be used for the application.
*/

/* 
* Copyright (C) 2009-2015 Texas Instruments Incorporated - www.ti.com 
* 
* 
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*  modification, are permitted provided that the following conditions 
*  are met:
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*    notice, this list of conditions and the following disclaimer.
*
*    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.
*
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*    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 
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*  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
*  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
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*  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.
*
*/


/* USER CODE BEGIN (0) */
/* USER CODE END */

/* Include Files */

#include "sys_common.h"

/* USER CODE BEGIN (1) */
#include "spi.h"
#include "i2c.h"
/* USER CODE END */

/** @fn void main(void)
*   @brief Application main function
*   @note This function is empty by default.
*
*   This function is called after startup.
*   The user can use this function to implement the application.
*/

/* USER CODE BEGIN (2) */
/* Variables for I2C Communication*/
unsigned int pstatus=0x001;

int I2C_Read_M(short Slave_Add, short Read_Add,
               short Count,     uint8 *buff );

int I2C_Write_M(short Slave_Add, short Read_Add,
                short Count,     uint8 *buff );

void delay(void) {
	  static volatile uint32_t delayval;
	  delayval = 10000;                     //100000 are about 10ms
	  while(delayval--);
}

/* USER CODE END */

void main(void)
{
	 int error,  Count, Register;

	 short Slave_Addr  = 0x32;        // 0-1-1-0-0-1-0-R/W-A
	 short Own_Addr    = 0x26;        // Define Master Own Address
	 uint8 TxData[10]  = {
	 	    		    	 0x18,
	 					     0x26,
		 				     0x12,
	 					     0x10,
	 					     0x14,
							 0x04,
							 0x16
	 					 };
	 uint8 RxData[10]  = {
	                         0
	                     };
	 uint8 RxData1[10]  = {
	                         0
	                     };
	 uint8 RxData2[10]  = {
	                         0
	                     };
	 uint8 RxData3[10]  = {
	                         0
	                     };

	 error = 0x00;

	/* I2C Init as per GUI
	 *  Mode = Master - Transmitter
	 *  baud rate = 100KHz
	 *  Count = 10
	 *  Bit Count = 8bit
	 */
	 i2cInit();

	 i2cSetOwnAdd(i2cREG1, Own_Addr);

	 Register = 0x00;          // Select Configuration Register
	 Count    = 0x07;
     delay();  //at least 61uS delay is required by RTC datasheet
	 error = I2C_Write_M(Slave_Addr, Register, Count, TxData);

	 Register = 0x00;         // 0x00/01//02//03 "second/min/hour/week/day/month/year" register
	 Count    = 0x7;          // 4 bytes for week, day, month, year
     delay();  //at least 61uS delay is required by RTC datasheet
	 error = I2C_Read_M(Slave_Addr, Register, Count, RxData);

     delay();  //at least 61uS delay is required by RTC datasheet
	 error = I2C_Read_M(Slave_Addr, Register, Count, RxData1);

     delay();  //at least 61uS delay is required by RTC datasheet
	 error = I2C_Read_M(Slave_Addr, Register, Count, RxData2);

     delay();  //at least 61uS delay is required by RTC datasheet
	 error = I2C_Read_M(Slave_Addr, Register, Count, RxData3);

	 if (error==0)
		pstatus=0x000;
	 else
	 	pstatus=0x001;

/* USER CODE END */
}

/* USER CODE BEGIN (4) */

/* Read from a slave device */
int I2C_Read_M(short Slave_Add, short Read_Add, short Count, uint8 *buff)
{
	int i, error, dummy;
	error = 0;

    if((i2cREG1->STR & I2C_BUSBUSY ) == 0) //test if Busy is busy
    {
        /* Clear Stop bit */
        i2cREG1->MDR &= ~(I2C_STOP_COND);
        /* Clear Start bit */
        i2cREG1->MDR &= ~(I2C_START_COND);
        /* Clear Repeat mode bit */
        i2cREG1->MDR &= ~(I2C_REPEATMODE);

        /* Set direction to Transmitter */
        i2cSetDirection(i2cREG1, I2C_TRANSMITTER);
        /* Set mode as Master */
        i2cSetMode(i2cREG1, I2C_MASTER);
        /* Configure Data count */
        i2cSetCount(i2cREG1, 0x01);  //for 1-byte read address

        /* Configure address of Slave to talk to */
        i2cSetSlaveAdd(i2cREG1, Slave_Add);

        /* send the read address */
        i2cSendByte(i2cREG1, Read_Add);

        /* Start transmit*/
        i2cSetStart(i2cREG1);   //Start the transmission:
                                //I2C Bus: Start--Slave Addr--Read Addr

        while( ((i2cREG1->STR & I2C_NACK) == 0) && ((i2cREG1->STR & I2C_ARDY) == 0) );

        if((i2cREG1->STR & I2C_NACK) == 0)  // Check for Positive Acknoledge
        {                                      // Application can continue
            /* Set mode as Master, and Receiver */
            i2cSetMode(i2cREG1, I2C_MASTER);         // Switch to Master Receiver
            i2cSetDirection(i2cREG1, I2C_RECEIVER);
            /* Set Repeat start mode */
            i2cREG1->MDR |= I2C_REPEATMODE;

            /* Start transmit*/
            i2cSetStart(i2cREG1);   //I2C BUS: Start--Slave Addr

            for (i=0; i<Count; i++)
            {
                 buff[i] = i2cReceiveByte(i2cREG1);  // Read incoming data and store in array
                 if (i == Count-2){
                    i2cSetStop(i2cREG1); //to generate a STOP
                 }
            }
        }
        else
        {
            dummy = i2cREG1->IVR;   // Clear nack flag
        	i2cSetStop(i2cREG1);    // to generate a STOP
        	error=-2;               // Set error as NoAck
        }
    }
    else{
    	error = -1; // Set error as Bus Busy
    }

    while((i2cREG1->MDR & I2C_STOP_COND) ==1);

    return error;
}


/* Write to a slave device */
int I2C_Write_M(short Slave_Add, short Write_Add, short Count, uint8 *buff )
{
	int error, dummy;                 // Return code
    error = 0x00;                               // Default, no error

    if((i2cREG1->STR & I2C_BUSBUSY ) == 0) //test if Busy is busy
    {
        /* Set direction to Transmitter */
        i2cSetDirection(i2cREG1, I2C_TRANSMITTER);
        /* Set mode as Master */
        i2cSetMode(i2cREG1, I2C_MASTER);

        /* Clear Start bit */
        i2cREG1->MDR &= ~(I2C_START_COND);
		/* Set Stop after programmed Count */
		i2cSetStop(i2cREG1);

		/* Clear RM bit */
	    i2cREG1->MDR &= ~(I2C_REPEATMODE);   // Not in Repeat Mode

	    /* Configure Data count */
	    i2cSetCount(i2cREG1, Count+1);

        /* Configure address of Slave to talk to */
        i2cSetSlaveAdd(i2cREG1, Slave_Add);

		/* Transmit Start Condition */
		i2cSetStart(i2cREG1);         //I2C Bus: Start--Slave Addr

	    /* send the write address */
	    i2cSendByte(i2cREG1, Write_Add);  // Transmit data to Select Destination Register

	    if((i2cREG1->STR & I2C_NACK) == 0)  // Check for Positive Acknoledge
	    {
			/* Tranmit DATA_COUNT number of data in Polling mode */
			i2cSend(i2cREG1, Count, buff);
	    }
	    else{
            dummy = i2cREG1->IVR;   // Clear nack flag
        	i2cSetStop(i2cREG1);    // to generate a STOP
        	error=-2;               // Set error as NoAck
        }
    }
    else{
    	error = -1; // Set error as Bus Busy
    }

    while((i2cREG1->MDR & I2C_STOP_COND) ==1);

    return error;
}

/* USER CODE END */