uint8_t i2c_send_start(void)
{
    uint8_t timeout_count = 0;

    /* Send START condition. */
    LPC_I2C1->I2CONSET = 0x1 << I2CONSET_STA;

    /* Wait until START condition is sent. */
    do {
        /* If the transmission takes longer than TIMEOUT, returns error. */
        if (timeout_count++ >= I2C_START_TIMEOUT)
            return I2C_FUNCTION_RETCODE_TIMEOUT;
    } while (!(LPC_I2C1->I2CONSET & (0x1 << I2CONSET_SI)));

    /* If the status code differs from I2C_STARTED, returns error. */
    if (i2c_get_status() != I2C_STARTED)
        return I2C_FUNCTION_RETCODE_COMM_FAIL;

    /* Clear bit START. */
    LPC_I2C1->I2CONCLR = 0x1 << I2CONSET_STA;
    /* Everything went well. */
    return I2C_FUNCTION_RETCODE_SUCCESS;
}