tmp_112_i2c.txt

#include <msp430F5529.h>
#include <stdlib.h>                               //Processor specific definitions
#include <stdio.h>


unsigned char SADDR = 0x48;        //Slave address for TMP112 WRITE TO 0b01001000
unsigned char RADDR = 0x00;       //Slave register address for TMP112

unsigned char temp= 0x00;                   //assign temperature variable

void using_TMP112_temperature_ic();


int main( void )
{
WDTCTL = WDTPW + WDTHOLD;               // Stop WDT

//set clock freq 8 Mhz

while(1)
{
using_TMP112_temperature_ic();

}
}

void using_TMP112_temperature_ic()
{
        P4SEL |= BIT1|BIT2;                        //4.2=SDA -  4.3=CLK
        P3SEL &=~ BIT3;///ALERT pin
        P3DIR |= BIT3;
        P3OUT &=~ BIT3;

        UCB1CTL1 |= UCSWRST;                       // Enable SoftWare reset
        UCB1CTL0 = UCMST + UCMODE_3 + UCSYNC;      // Mode: Master, I2C, synchronous
        UCB1CTL1 = UCSSEL_2 + UCSWRST;             // Use SMCLK, keep SW reset
        UCB1BR0 = 80; // fSCL = SMCLK/80 = ~100kHz
        UCB1BR1 = 0;
        UCB1I2CSA = SADDR;                           //Set Slave address 0x48
        UCB1CTL1 &= ~UCSWRST;                      // Clear SW reset, resume operation
        UCB1CTL0 &= ~UCSLA10;                      // Enable 7 bit slave address option
        UCB1CTL1 |= UCTR;                          // Master is a transmitter
        UCB1CTL1 |= UCTXSTT;                       // Staart : TXIFG flag is raised


        unsigned char hold = 0x00;

        while (hold == 0x00)
        {
            hold = UCB1IFG;                //wait until slave address is sent completely
        }
        UCB1TXBUF = RADDR;                        // input register add=0x00 into TXBUF, TXIFG flag cleared
        hold = 0x00;


        // Select configuration register
        while (hold == 0x00)
        {
            hold = UCB1IFG;
        }
        UCB1TXBUF = 0x01;
        hold = 0x00;

        // Continuous conversion, comparator mode, 12-bit resolution
      while (hold == 0x00)
        {
            hold = UCB1IFG;
        }
        UCB1TXBUF = 0x60;
        hold = 0x00;

     while (hold == 0x00)
        {
            hold = UCB1IFG;
        }
        UCB1TXBUF = 0xA0;
        hold = 0x00;
        //----------------------------------------------------------------------------------------------

        //clear hold variable for next wait cycle

        //TMP112 is now setup with it being addressed and its register when temp data is now address
        //Now starting the Master Receiver mode where the TMP112 will be outputting temperature data to MSP430
        //Master Receiver Mode

        UCB1CTL1 &= ~UCTR;                                    // Master is a receiver
        UCB1CTL1 |= UCTXSTT;                                 // Repeated Staart

       while (hold == 0x00)
        {
            hold = UCB1IFG;                   // Wait for RX Interrupt flag
        }
        temp_112[0] = UCB1RXBUF;
        hold = 0x00;

        while (hold == 0x00)
        {
            hold = UCB1IFG;                       // Wait for RX Interrupt flag
        }
        temp_112[1] = UCB1RXBUF;
        hold = 0x00;
        UCB1CTL1 |= UCTXSTP;                                   // I2C stop condition


        TMP_112_temp=((temp_112[0]*256+temp_112[1])/16)*0.0625;     //TMP112 -temperature calculation equation    ---if temp_112[0]=6 and temp_112[1]=64 then temp is 100 C  -->  0.0625 used to convert in C


        __delay_cycles(300);//put break point here u will get temp

}