/* Initialize the master TWI. 
Function used to initialize master TWI interface that would communicate with simulated EEPROM. */
static ret_code_t twi_master_init(void)
/* Initialize the master TWI. 
Function used to initialize master TWI interface that would communicate with simulated EEPROM. */
static ret_code_t twi_master_init(void)
{
    ret_code_t ret;
    const nrf_drv_twi_config_t config =
    {
       .scl                = TWI_SCL_M,
       .sda                = TWI_SDA_M,
       .frequency          = NRF_TWI_FREQ_400K,
       .interrupt_priority = APP_IRQ_PRIORITY_HIGH,
       .clear_bus_init     = false
    };
    ret = nrf_drv_twi_init(&m_twi_master, &config, NULL, NULL);
    if (NRF_SUCCESS == ret)
    {
        nrf_drv_twi_enable(&m_twi_master);
    }
    return ret;
}