加速度センサー（MMA8452Q）を使いこなす

#include "mcc_generated_files/mcc.h"
#include <stdlib.h>

#define MMA8452_ADRS 0x1D    
#define MMA8452_STATUS 0x00
#define MMA8452_XYZ_DATA_CFG 0x0E
#define MMA8452_CTRL_REG1 0x2A
#define MMA8452_CTRL_REG1_ACTV_BIT 0x01
#define MMA8452_WHO_AM_I 0x0D
#define MMA8452_CTRL_REG1_CONFIG 0x00
#define MMA8452_G_SCALE 2
#define SLAVE_I2C_GENERIC_RETRY_MAX 10

uint8_t g_buf[7] = {0, 0, 0, 0, 0, 0, 0};

void writeI2C(uint8_t addr, uint8_t* writeData, uint8_t len) {
    I2C_MESSAGE_STATUS status;
    I2C_MasterWrite(writeData, len, addr, &status);
    while (status == I2C_MESSAGE_PENDING){
        __delay_us(100);
    }
}

void readI2C(uint8_t addr, uint8_t reg, uint8_t* readData, uint8_t len) {
    
    I2C_MESSAGE_STATUS status;
    I2C_TRANSACTION_REQUEST_BLOCK readTRB[2];
    uint16_t    timeOut;

    // this initial value is important
    status = I2C_MESSAGE_PENDING;

    // we need to create the TRBs for a random read sequence to the EEPROM
    // Build TRB for sending address
    I2C_MasterWriteTRBBuild(   &readTRB[0],
                                    &reg,
                                    1,
                                    addr);
    // Build TRB for receiving data
    I2C_MasterReadTRBBuild(    &readTRB[1],
                                    readData,
                                    len,
                                    addr);

    timeOut = 0;

    while(status != I2C_MESSAGE_FAIL)
    {
        // now send the transactions
        I2C_MasterTRBInsert(2, readTRB, &status);

        // wait for the message to be sent or status has changed.
        while(status == I2C_MESSAGE_PENDING){
            __delay_us(100);
        }

        if (status == I2C_MESSAGE_COMPLETE)
            break;

        // if status is  I2C_MESSAGE_ADDRESS_NO_ACK,
        //               or I2C_DATA_NO_ACK,
        // The device may be busy and needs more time for the last
        // write so we can retry writing the data, this is why we
        // use a while loop here

        // check for max retry and skip this byte
        if (timeOut == SLAVE_I2C_GENERIC_RETRY_MAX)
            break;
        else
            timeOut++;
    }
}

void printSerial(uint8_t* data, uint8_t len) {
    for(int i = 0; i < len; i++) {
        EUSART_Write(data[i]);
    }
}

void initMMA8452Q() {
    uint8_t len = 1;
    I2C_MESSAGE_STATUS status;

    readI2C(MMA8452_ADRS, MMA8452_WHO_AM_I, &g_buf, 1);
    printSerial(g_buf, 1);
    
    g_buf[1] = 0x00;
    g_buf[0] = MMA8452_CTRL_REG1;
    writeI2C(MMA8452_ADRS, g_buf, 2);
    printSerial(g_buf, 2);

    g_buf[0] = MMA8452_XYZ_DATA_CFG;
    g_buf[1] = (MMA8452_G_SCALE >> 2);
    writeI2C(MMA8452_ADRS, g_buf, 2);
    printSerial(g_buf, 2);

    readI2C(MMA8452_ADRS, MMA8452_CTRL_REG1, &g_buf, 1);
    printSerial(g_buf, 1);
    
    g_buf[1] = MMA8452_CTRL_REG1_CONFIG | MMA8452_CTRL_REG1_ACTV_BIT;
    g_buf[0] = MMA8452_CTRL_REG1;
    writeI2C(MMA8452_ADRS, g_buf, 2);
}

void main(void)
{
    // initialize the device
    SYSTEM_Initialize();

    // When using interrupts, you need to set the Global and Peripheral Interrupt Enable bits
    // Use the following macros to:

    // Enable the Global Interrupts
    INTERRUPT_GlobalInterruptEnable();

    // Enable the Peripheral Interrupts
    INTERRUPT_PeripheralInterruptEnable();

    // Disable the Global Interrupts
    //INTERRUPT_GlobalInterruptDisable();

    // Disable the Peripheral Interrupts
    //INTERRUPT_PeripheralInterruptDisable();

    __delay_ms(1000);
    
    initMMA8452Q();
    
    readI2C(MMA8452_ADRS, MMA8452_STATUS, &g_buf, 7);
    
    while (1)
    {
        readI2C(MMA8452_ADRS, MMA8452_STATUS, &g_buf, 7);
        printSerial(g_buf, 6);

        __delay_ms(1000);
    }
}