I2C驱动代码

P3.0为SDA，P3.1为SCL

MSP430F5529_I2C.c

#include "driverlib.h"

#define I2C_USCI_BASE USCI_B0_BASE
#define I2C_USCI_VECTOR USCI_B0_VECTOR
#define I2C_USCI_IV UCB0IV

#define I2C_BUF_LENGTH 32
static char i2c_buf[I2C_BUF_LENGTH];
static uint8_t i2c_buf_len = 0;
static uint8_t i2c_buf_cur = 0;

static uint8_t *i2c_rx_buf = 0;
static uint8_t i2c_rx_buf_len = 0;

void Init_I2C_GPIO(void)
{
    /* Select I2C function for I2C_SDA & I2C_SCL */
    GPIO_setAsPeripheralModuleFunctionOutputPin(
            GPIO_PORT_P3,
            GPIO_PIN0 | GPIO_PIN1);
}


/***************************************************************************//**
 * @brief  Configures I2C
 * @param  none
 * @return none
 ******************************************************************************/

void I2C_init(uint8_t slaveAddress)
{
  /* I2C Master Configuration Parameter */
  USCI_B_I2C_initMasterParam i2cConfig =
  {
    USCI_B_I2C_CLOCKSOURCE_SMCLK,
    UCS_getSMCLK(),
    USCI_B_I2C_SET_DATA_RATE_400KBPS
  };
  /* Initialize USCI_B0 and I2C Master to communicate with slave devices*/
  USCI_B_I2C_initMaster(I2C_USCI_BASE, &i2cConfig);

  /* Enable I2C Module to start operations */
  USCI_B_I2C_enable(I2C_USCI_BASE);

  // Specify slave address
  USCI_B_I2C_setSlaveAddress(I2C_USCI_BASE, slaveAddress);
  USCI_B_I2C_clearInterrupt(I2C_USCI_BASE, USCI_B_I2C_RECEIVE_INTERRUPT);
  USCI_B_I2C_enableInterrupt(I2C_USCI_BASE, USCI_B_I2C_RECEIVE_INTERRUPT);
  USCI_B_I2C_clearInterrupt(I2C_USCI_BASE, USCI_B_I2C_TRANSMIT_INTERRUPT);
  USCI_B_I2C_enableInterrupt(I2C_USCI_BASE, USCI_B_I2C_TRANSMIT_INTERRUPT);

    return;
}


/* write a byte to specific register, cannot called in interrupt context */
void writeByte(uint8_t byte)
{
    while (USCI_B_I2C_isBusBusy(I2C_USCI_BASE));

    USCI_B_I2C_setMode(I2C_USCI_BASE, USCI_B_I2C_TRANSMIT_MODE);

    // Initiate start and send first character
    i2c_buf[0] = byte;
    i2c_buf_cur = 1;
    i2c_buf_len = 1;
    USCI_B_I2C_masterSendMultiByteStart(I2C_USCI_BASE, i2c_buf[0]);

    // wait for end
    __bis_SR_register(GIE + LPM0_bits);
    __no_operation();
}

/* write a word to specific register, cannot called in interrupt context */
void writeWord(uint16_t word)
{
    while (USCI_B_I2C_isBusBusy(I2C_USCI_BASE));

    USCI_B_I2C_setMode(I2C_USCI_BASE, USCI_B_I2C_TRANSMIT_MODE);

    // Initiate start and send first character
    i2c_buf[0] = word >> 8;
    i2c_buf[1] = (uint8_t)word;
    i2c_buf_cur = 1;
    i2c_buf_len = 2;
    USCI_B_I2C_masterSendMultiByteStart(I2C_USCI_BASE, i2c_buf[0]);

    // wait for end
    __bis_SR_register(GIE + LPM0_bits);
    __no_operation();
}

///* set/clear some bit to specific register, cannot called in interrupt context */
//void writeBit(uint8_t regAddr, uint8_t bitNum, uint8_t data)
//{
//    uint8_t b = 0;
//    readByte(regAddr, &b);
//    delay_ms(2);
//    b = (data != 0) ? (b | (1 << bitNum)) : (b & ~(1 << bitNum));
//    writeByte(regAddr, b);
//}

/* read some byte from specific register, cannot called in interrupt context */
void readByte(uint8_t RegAddr, uint8_t* b)
{
	while (USCI_B_I2C_isBusBusy(I2C_USCI_BASE));

    // send address
    USCI_B_I2C_setMode(I2C_USCI_BASE, USCI_B_I2C_TRANSMIT_MODE);
    i2c_buf_cur = 1;
    i2c_buf_len = 1;
    USCI_B_I2C_masterSendSingleByte(I2C_USCI_BASE, RegAddr);

    // receive
    USCI_B_I2C_setMode(I2C_USCI_BASE, USCI_B_I2C_RECEIVE_MODE);
    i2c_rx_buf = b;
    i2c_rx_buf_len = 1;
    USCI_B_I2C_masterReceiveSingleStart(I2C_USCI_BASE);

//     wait for end
    __bis_SR_register(GIE + LPM0_bits);
    __no_operation();
}

void readBytes(uint8_t RegAddr, uint8_t length, uint8_t* data)
{
	while (USCI_B_I2C_isBusBusy(I2C_USCI_BASE));
    // send address
    USCI_B_I2C_setMode(I2C_USCI_BASE, USCI_B_I2C_TRANSMIT_MODE);
    i2c_buf_cur = 1;
    i2c_buf_len = 1;
    USCI_B_I2C_masterSendSingleByte(I2C_USCI_BASE, RegAddr);

    // receive
    USCI_B_I2C_setMode(I2C_USCI_BASE, USCI_B_I2C_RECEIVE_MODE);
    i2c_rx_buf = data;
    i2c_rx_buf_len = length;
    USCI_B_I2C_masterReceiveMultiByteStart(I2C_USCI_BASE);

    // wait for end
    __bis_SR_register(GIE + LPM0_bits);
    __no_operation();
}

#pragma vector = I2C_USCI_VECTOR
__interrupt void USCI_B0_ISR(void)
{
    switch (__even_in_range(I2C_USCI_IV, 12))
    {
        case USCI_I2C_UCTXIFG:
            if (i2c_buf_cur < i2c_buf_len)
            {
                USCI_B_I2C_masterSendMultiByteNext( I2C_USCI_BASE, i2c_buf[i2c_buf_cur]);
                i2c_buf_cur++;
            }
            else
            {
                USCI_B_I2C_masterSendMultiByteStop(I2C_USCI_BASE);
                //Clear master interrupt status
                USCI_B_I2C_clearInterrupt(I2C_USCI_BASE,
                                          USCI_B_I2C_TRANSMIT_INTERRUPT);
                __bic_SR_register_on_exit(LPM0_bits);
            }
            break;
        case USCI_I2C_UCRXIFG:
            i2c_rx_buf_len--;
            if(i2c_rx_buf_len)
            {
                if(i2c_rx_buf_len== 1)
                {
                    //Initiate end of reception -> Receive byte with NAK
                    *i2c_rx_buf++ = USCI_B_I2C_masterReceiveMultiByteFinish( I2C_USCI_BASE);
                }
                else
                {
                    //Keep receiving one byte at a time
                    *i2c_rx_buf++ = USCI_B_I2C_masterReceiveMultiByteNext( I2C_USCI_BASE);
                }
            }
            else
            {
                //Receive last byte
                *i2c_rx_buf= USCI_B_I2C_masterReceiveMultiByteNext(I2C_USCI_BASE);
                __bic_SR_register_on_exit(LPM0_bits);
            }
            break;
    }
}

MSP430F5529_I2C.h

#ifndef MSP430F5529_I2C_H_
#define MSP430F5529_I2C_H_

void Init_I2C_GPIO(void);
void I2C_init(uint8_t slaveAddress);
void writeByte(uint8_t byte);
void writeWord(uint16_t word);
void readByte(uint8_t RegAddr, uint8_t* b);
void readBytes(uint8_t RegAddr, uint8_t length, uint8_t* data);

#endif /* MSP430F5529_I2C_H_ */

OLED初始化及测试

#include "driverlib.h"
#include "MSP430F5529_I2C.h"
#include "./OLED/OLED.h"

#define MCLK_IN_HZ      25000000

#define delay_us(x)     __delay_cycles((MCLK_IN_HZ/1000000*(x)))
#define delay_ms(x)     __delay_cycles((MCLK_IN_HZ/1000*(x)))

void SystemClock_Init(void)
{
    PMM_setVCore(PMM_CORE_LEVEL_3);     //高主频工作需要较高的核心电压

    //XT1引脚复用
    GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P5, GPIO_PIN4);
    GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P5, GPIO_PIN5);

    //起振XT1
    UCS_turnOnLFXT1(UCS_XT1_DRIVE_3,UCS_XCAP_3);

    //XT2引脚复用
    GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P5, GPIO_PIN2);
    GPIO_setAsPeripheralModuleFunctionOutputPin(GPIO_PORT_P5, GPIO_PIN3);

    //起振XT2
    UCS_turnOnXT2(UCS_XT2_DRIVE_4MHZ_8MHZ);

    //XT2作为FLL参考时钟，先8分频，再50倍频 4MHz / 8 * 50 = 25MHz
    UCS_initClockSignal(UCS_FLLREF, UCS_XT2CLK_SELECT, UCS_CLOCK_DIVIDER_8);
    UCS_initFLLSettle(25000, 50);

    //XT1作为ACLK时钟源 = 32768Hz
    UCS_initClockSignal(UCS_ACLK, UCS_XT1CLK_SELECT, UCS_CLOCK_DIVIDER_1);

    //DCOCLK作为MCLK时钟源 = 25MHz
    UCS_initClockSignal(UCS_MCLK, UCS_DCOCLK_SELECT, UCS_CLOCK_DIVIDER_1);

    //DCOCLK作为SMCLK时钟源 = 25MHz
    UCS_initClockSignal(UCS_SMCLK, UCS_DCOCLK_SELECT, UCS_CLOCK_DIVIDER_1);

    //设置外部时钟源的频率，使得在调用UCS_getMCLK, UCS_getSMCLK 或 UCS_getACLK时可得到正确值
    UCS_setExternalClockSource(32768, 4000000);
}

int main(void)
{
    WDT_A_hold(WDT_A_BASE);
    SystemClock_Init();

    Init_I2C_GPIO();
    I2C_init(OLED_ADDRESS >> 1);

    __bis_SR_register(GIE);

	OLED_Init();
	OLED_Clear();
	OLED_Display_On();
	OLED_ShowString(0, 0, "MSP430F5529 OLED", 1);
	OLED_ShowString(0, 2, "   2021-08-05", 1);

    while(1)
    {
    	delay_ms(1000);
    }
}