File content as of revision 1:04b7521f737d:

# include<mbed.h>

I2C i2c(D4, D5);//sda,scl
Serial pc(USBTX,USBRX);

void main() 
{
    /*
    // Create I2C bus
    int file;
    //ここから下6行はいらないかも
    char *bus = "/dev/i2c-1";
    if((file = open(bus, O_RDWR)) < 0) 
    {
        printf("Failed to open the bus. \n");
        exit(1);
    }
    
    // Get I2C device, L3GD20 I2C address is 0x6A(106)
   // ioctl(file, I2C_SLAVE, 0x6A);
    slave.address(0x6A);    //1101010のことやと思うからSA0をGNDにつなげばいいと思う
    int i = slave.receive();
*/
    const int addr = 0x6A;
    // Enable X, Y, Z-Axis and disable Power down mode(0x0F)
    char config[2] = {0};
    config[0] = 0x20;
    config[1] = 0x0F;
    i2c.write(addr, config, 2);
    // Full scale range, 2000 dps(0x30)
    config[0] = 0x23;
    config[1] = 0x30;
    i2c.write(addr, config, 2);
    wait(1);

    // Read 6 bytes of data
    // lsb first
    // Read xGyro lsb data from register(0x28)
    char reg[1] = {0x28};
    i2c.write(addr, reg, 1);
    char data[1] = {0};
    if(i2c.read(addr, data, 1) != 1)
    {
        printf("Error : Input/Output Error \n");
        exit(1);
    }
    char data_0 = data[0];

    // Read xGyro msb data from register(0x29)
    reg[0] = 0x29;
    i2c.write(addr, reg, 1);
    i2c.read(addr, data, 1);
    char data_1 = data[0];

    // Read yGyro lsb data from register(0x2A)
    reg[0] = 0x2A;
    i2c.write(addr, reg, 1);
    i2c.read(addr, data, 1);
    char data_2 = data[0];

    // Read yGyro msb data from register(0x2B)
    reg[0] = 0x2B;
    i2c.write(addr, reg, 1);
    i2c.read(addr, data, 1);
    char data_3 = data[0];

    // Read zGyro lsb data from register(0x2C)
    reg[0] = 0x2C;
    i2c.write(addr, reg, 1);
    i2c.read(addr, data, 1);
    char data_4 = data[0];

    // Read zGyro msb data from register(0x2D)
    reg[0] = 0x2D;
    i2c.write(addr, reg, 1);
    i2c.read(addr, data, 1);
    char data_5 = data[0];

    // Convert the data
    int xGyro = (data_1 * 256 + data_0);
    if(xGyro > 32767)
    {
        xGyro -= 65536;
    }

    int yGyro = (data_3 * 256 + data_2);
    if(yGyro > 32767)
    {
        yGyro -= 65536;
    }

    int zGyro = (data_5 * 256 + data_4);
    if(zGyro > 32767)
    {
    zGyro -= 65536;
    }

    // Output data to screen
    while(1){
    printf("Rotation in X-Axis : %d \n", xGyro);
    printf("Rotation in Y-Axis : %d \n", yGyro);
    printf("Rotation in Z-Axis : %d \n", zGyro);
    wait(0.5);
        }
    
}