diff --git a/lib/sdk11/components/libraries/bootloader_dfu/dfu_transport_ble.c b/lib/sdk11/components/libraries/bootloader_dfu/dfu_transport_ble.c
index 65bc503..f5ebb33 100644
--- a/lib/sdk11/components/libraries/bootloader_dfu/dfu_transport_ble.c
+++ b/lib/sdk11/components/libraries/bootloader_dfu/dfu_transport_ble.c
@@ -704,7 +704,8 @@ static void advertising_start(void)
     APP_ERROR_CHECK( sd_ble_gap_adv_set_configure(&_adv_handle, &gap_adv, &m_adv_params) );
     // maximum power for nrf52832, nrf52840 max power is +8
     APP_ERROR_CHECK( sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, _adv_handle, 4) );
-    APP_ERROR_CHECK( sd_ble_gap_adv_start(_adv_handle, BLE_CONN_CFG_HIGH_BANDWIDTH) );
+//    APP_ERROR_CHECK( sd_ble_gap_adv_start(_adv_handle, BLE_CONN_CFG_HIGH_BANDWIDTH) );
+    APP_ERROR_CHECK( sd_ble_gap_adv_start(_adv_handle, BLE_CONN_CFG_TAG_DEFAULT) );
 
     m_is_advertising = true;
   }
diff --git a/src/main.c b/src/main.c
index 53fde55..3ae51ea 100644
--- a/src/main.c
+++ b/src/main.c
@@ -153,7 +153,7 @@ static uint32_t softdev_init(bool init_softdevice)
   // Enable Softdevice
   nrf_clock_lf_cfg_t clock_cfg =
   {
-#ifdef NRF52840_XXAA // TODO use xtal source for feather52832
+#if defined(NRF52840_XXAA) // TODO use xtal source for feather52832
       .source       = NRF_CLOCK_LF_SRC_XTAL,
       .rc_ctiv      = 0,
       .rc_temp_ctiv = 0,
@@ -173,10 +173,12 @@ static uint32_t softdev_init(bool init_softdevice)
   extern uint32_t  __data_start__[]; // defined in linker
   uint32_t ram_start = (uint32_t) __data_start__;
 
+#if 0
   ble_cfg_t blecfg;
 
   // Configure the maximum number of connections.
   varclr(&blecfg);
+  blecfg.gap_cfg.role_count_cfg.adv_set_count = 1;
   blecfg.gap_cfg.role_count_cfg.periph_role_count  = 1;
   blecfg.gap_cfg.role_count_cfg.central_role_count = 0;
   blecfg.gap_cfg.role_count_cfg.central_sec_count  = 0;
@@ -199,11 +201,19 @@ static uint32_t softdev_init(bool init_softdevice)
   blecfg.conn_cfg.params.gap_conn_cfg.conn_count   = 1;
   blecfg.conn_cfg.params.gap_conn_cfg.event_length = BLEGAP_EVENT_LENGTH;
   APP_ERROR_CHECK( sd_ble_cfg_set(BLE_CONN_CFG_GAP, &blecfg, ram_start) );
+#endif
 
   // Enable BLE stack.
   // Note: Interrupt state (enabled, forwarding) is not work properly if not enable ble
   APP_ERROR_CHECK( sd_ble_enable(&ram_start) );
 
+#if 0
+  ble_opt_t  opt;
+  varclr(&opt);
+  opt.common_opt.conn_evt_ext.enable = 1; // enable Data Length Extension
+  APP_ERROR_CHECK( sd_ble_opt_set(BLE_COMMON_OPT_CONN_EVT_EXT, &opt) );
+#endif
+
   return NRF_SUCCESS;
 }
 
@@ -216,6 +226,8 @@ int main(void)
   _ota_update = (NRF_POWER->GPREGRET == BOOTLOADER_DFU_OTA_MAGIC) ||
                 (NRF_POWER->GPREGRET == BOOTLOADER_DFU_OTA_FULLRESET_MAGIC);
 
+  _ota_update = 1; // force OTA for testing
+
   // start bootloader either serial or ble
   bool dfu_start = _ota_update || (NRF_POWER->GPREGRET == BOOTLOADER_DFU_SERIAL_MAGIC);
 
@@ -342,7 +354,7 @@ void app_error_fault_handler(uint32_t id, uint32_t pc, uint32_t info)
 
 void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
 {
-  app_error_handler(0xDEADBEEF, line_num, p_file_name);
+  app_error_fault_handler(0xDEADBEEF, 0, 0);
 }
 
 /*------------------------------------------------------------------*/