eusci_b_i2c_ex2_masterRxSingle.c

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//*****************************************************************************
 
//
//*****************************************************************************
#include "driverlib.h"
 
//*****************************************************************************
//
//Set the address for slave module. This is a 7-bit address sent in the
//following format:
//[A6:A5:A4:A3:A2:A1:A0:RS]
//
//A zero in the "RS" position of the first byte means that the master
//transmits (sends) data to the selected slave, and a one in this position
//means that the master receives data from the slave.
//
//*****************************************************************************
#define SLAVE_ADDRESS 0x48
 
//*****************************************************************************
//
//Target frequency for SMCLK in kHz
//
//*****************************************************************************
#define CS_SMCLK_DESIRED_FREQUENCY_IN_KHZ   1000
 
//*****************************************************************************
//
//SMCLK/FLLRef Ratio
//
//*****************************************************************************
#define CS_SMCLK_FLLREF_RATIO   30
 
uint8_t RXData;
void main (void)
{
    //Stop WDT
    WDT_A_hold(WDT_A_BASE);
 
    //Set Ratio and Desired MCLK Frequency  and initialize DCO
    CS_initFLLSettle(
        CS_SMCLK_DESIRED_FREQUENCY_IN_KHZ,
        CS_SMCLK_FLLREF_RATIO
        );
 
    //Set SMCLK = DCO with frequency divider of 1
    CS_initClockSignal(
            CS_SMCLK,
            CS_DCOCLKDIV_SELECT,
            CS_CLOCK_DIVIDER_1
            );
 
    //Set MCLK = DCO with frequency divider of 1
    CS_initClockSignal(
            CS_MCLK,
            CS_DCOCLKDIV_SELECT,
            CS_CLOCK_DIVIDER_1
            );
 
    // Configure Pins for I2C
    /*
    * Select Port 5
    * Set Pin 2, 3 to input with function, (UCB0SIMO/UCB0SDA, UCB0SOMI/UCB0SCL).
    */
    GPIO_setAsPeripheralModuleFunctionInputPin(
        GPIO_PORT_P5,
        GPIO_PIN2 + GPIO_PIN3,
        GPIO_PRIMARY_MODULE_FUNCTION
    );
 
    //Set P1.0 as an output pin.
    /*
 
     * Select Port 1
     * Set Pin 0 as output
     */
    GPIO_setAsOutputPin(
        GPIO_PORT_P1,
        GPIO_PIN0
    );
 
    /*
     * Disable the GPIO power-on default high-impedance mode to activate
     * previously configured port settings
     */
    PMM_unlockLPM5();
 
    EUSCI_B_I2C_initMasterParam param = {0};
    param.selectClockSource = EUSCI_B_I2C_CLOCKSOURCE_SMCLK;
    param.i2cClk = CS_getSMCLK();
    param.dataRate = EUSCI_B_I2C_SET_DATA_RATE_400KBPS;
    param.byteCounterThreshold = 1;
    param.autoSTOPGeneration = EUSCI_B_I2C_SEND_STOP_AUTOMATICALLY_ON_BYTECOUNT_THRESHOLD;
    EUSCI_B_I2C_initMaster(EUSCI_B0_BASE, &param);
 
    //Specify slave address
    EUSCI_B_I2C_setSlaveAddress(EUSCI_B0_BASE,
        SLAVE_ADDRESS
        );
 
    //Set Master in receive mode
    EUSCI_B_I2C_setMode(EUSCI_B0_BASE,
        EUSCI_B_I2C_RECEIVE_MODE
        );
 
    //Enable I2C Module to start operations
    EUSCI_B_I2C_enable(EUSCI_B0_BASE);
 
    EUSCI_B_I2C_clearInterrupt(EUSCI_B0_BASE,
        EUSCI_B_I2C_RECEIVE_INTERRUPT0 +
        EUSCI_B_I2C_BYTE_COUNTER_INTERRUPT
        );
 
    //Enable master Receive interrupt
    EUSCI_B_I2C_enableInterrupt(EUSCI_B0_BASE,
        EUSCI_B_I2C_RECEIVE_INTERRUPT0 +
        EUSCI_B_I2C_BYTE_COUNTER_INTERRUPT
        );
 
     while (1)
    {
      __delay_cycles(2000);
 
     // I2C start condition
      RXData = EUSCI_B_I2C_masterReceiveSingleByte(EUSCI_B0_BASE);
 
    }
}