Cannot get notifications data on BLE_NUS_C_EVT_NUS_RX_EVT

[Vitaliy]

Hi,

I am trying to change an example code on ble_app_uart_c (Central) SDK10.0.0 s130.

I have changed already peripheral example and I can see notification data if I connect to peripheral (ble_app_uart) via IOS LightBlue app.

But I could not get the same data via Central example, what I am missing?

Peripheral sends 20bytes via ble_nus_string_send after check:

if (p_ble_evt->evt.gatts_evt.params.write.handle == m_nus.rx_handles.cccd_handle) {

From Central I can see only:

Connected to target
[DB]: Starting discovery of service with UUID 0x1 for Connection handle 0
[DB]: Discovery of service with UUID 0x1 completed with success for Connectionhandle 0
The device has the device RX characteristic
The device has the device TX characteristic

Any help would be greatly appreciated.

Vitaliy

[Ole Bauck]

What exactly did you change? Are you getting the BLE_NUS_C_EVT_NUS_RX_EVT event?

[Vitaliy]

I changed only SCAN_WINDOW and made it the same as SCAN_INTERVAL.

Now I realize that Central actually receives sometimes data from Peripheral but not always:

The device has the device TX characteristic
p_ble_evt : 55
p_ble_evt : 56
Received RX_EVT
0123456@ABC`p_ble_evt : 56

Maybe there is nothing wrong with Central but with Peripheral...?

Peripheral side transfers 20 bytes data after it receives the event:

case BLE_GATTS_EVT_WRITE:						
`if (p_ble_evt->evt.gatts_evt.params.write.handle == m_nus.rx_handles.cccd_handle) {
#sending 20 bytes of data
   ble_nus_string_send(&m_nus, data_array, data_size);
   sd_ble_gap_disconnect(m_conn_handle,BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
}`

[Vitaliy]

I found the reason why I don't get notifications; it is because of distance. When Central and Peripheral are close enough: within 50 cm I get all notifications. If I move them further away from each other notifications start to drop, not all of them can be received by Central. And if the distance is more than 1.5m than Central will not get them at all.

I thought if a connection is established and Central can clearly get disconnect event then notifications are safe...

What would you suggest to get all notifications?

[Vitaliy]

Frustrated. I can get all 5 notifications from my iphone5s (LightBlue app as Central) 4m away from Nrf51 dongle (Peripheral).

[Ole Bauck]

I doubt it is because of distance. Why are you disconnecting after you send 20 bytes (in BLE_GATTS_EVT_WRITE case)?