Error - BLE_GAP_SEC_STATUS_OOB_NOT_AVAILABLE

[Noy12120]

Hi,

When connecting my Nrf52840 to a PC using BLE nfc, after connection is established, I encountered the following error : BLE_GAP_SEC_STATUS_OOB_NOT_AVAILABLE – Out of bound key not available.

This error appears no consistently (about 800 test all of them using BLE , about 3- 4  of them usually failed with this error )

BLE version – 4.2

Out of band mode – NFC_PAIRING_MODE_LESC_OOB

 

target device - NRF52840 FreeRTOS based application with soft device 140 7.2.0, sdk 17.2.

Can you please tell me what may be the reason for that issue?

[Sigurd]

Hi,

Some follow- up questions

1) You are getting a BLE_GAP_EVT_AUTH_STATUS event, with auth_status set to BLE_GAP_SEC_STATUS_OOB_NOT_AVAILABLE (0x82) ?

This error appears no consistently (about 800 test all of them using BLE , about 3- 4  of them usually failed with this error )

2) You are testing 800 different nRF52840 devices, and 3-4 of these devices fails with this error? And it's always the same devices that fails?

3) What PC is this? It has some kind of built-in NFC reader?

[Noy12120]

Hi, 

1. Yes

2. No , it always the same device

3. Using third party device which holds NFC and BLE implementation inside (TWN ELATEC)

After a few attempts it succeeds

BR, 

Noy

[Sigurd]

Noy12120 said:

it always the same device

If it's always the same devices that fails, I suspect some HW issue here. Maybe the NFC antenna is not connected properly ? or not tuned optimally.

.

[Noy12120]

Hi, 

I replaced the NFC antenna, and Checked the hardware - No problem were found, but is still failed for the same reason -

BLE_GAP_SEC_STATUS_OOB_NOT_AVAILABLE – Out of bound key not available.

do you have another idea?

[Noy12120]

The NRF52840, which is turned on and immediately start advertise, due to NFC trigger

Should we wait for something before start advertising?