Error 62 (0x3e): GATT CONN FAIL ESTABLISH

[MegaCpp]

Hi,

i use the nrf52833dk with ncs 2.6.0 and the official peripheral_uart example to test NUS.
When i use my new Galaxy Tab A8 (Android14) and try to connect to the board i get always an Error 62 (0x3e): GATT CONN FAIL ESTABLISH.

When i use the new Galaxy Tab A9 (Android14) or my Xiamoi 11 (Android 12) everything connects fine.
i also tried to use the internal RC

# Use the internal 32kHz RC oscillator

CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y

CONFIG_CLOCK_CONTROL_NRF_K32SRC_20PPM=y

but it did not work.. am i doing something wrong or is the Galaxy Tab A8 just cheap rubbish?

[Jared]

Hi,

When i use the new Galaxy Tab A9 (Android14) or my Xiamoi 11 (Android 12) everything connects fine.
i also tried to use the internal RC

Did it work before you reconfigured the board to use the internal RC instead of the external crystal?

Try setting CONFIG_CLOCK_CONTROL_NRF_K32SRC_500 instead of CONFIG_CLOCK_CONTROL_NRF_K32SRC_20PPM.

regards

Jared 

[MegaCpp]

Hi thank you for the fast reply.

Yes i tried both the external crystal as well as the internal with 500ppm accuracy.

I have just ordered a nrf52840-dk, to see if the problem still exists and is indeed Tablet related (factory reset of the tablet didn't help either)

I will report back.

[Jared]

Hi,

In the meantime you could test with a mobile phone if you download the nRF Connect app for Android or IOS,

regards

Jared

[MegaCpp]

MegaCpp said:

When i use the new Galaxy Tab A9 (Android14) or my Xiamoi 11 (Android 12) everything connects fine.

with the nrf52840dk i get the same behaviour, i still can't connect to the board with the  Galaxy Tab A8 (Android14) only the Galaxy Tab A9 (Android14) and the Xiamoi 11 (Android 12) can connect.

same problem with default central_and_peripheral_hr example.

XIAO BLE with custom firmware also has the same problem with Galaxy Tab A8. so it's Tablet related,

but the tablet can connect to a generic JBL audio Box via Bluetooth. Any Ideas what might be the problem? Should i better ask at Samsung support ?

[ovrebekk]

Hi 

Jared is currently on leave and I will help you out in the mean time. 

It is strange that this particular tablet would struggle to connect when using standard BLE examples on regular devkits. 

Is it the same problem if you run a Bluetooth sample on the nRF52840DK without making any changes to the LF configuration, so that the external 32kHz crystal is used? 

It would be interesting to get a Bluetooth sniffer trace showing what is happening when the tablet tries to connect, but possibly you don't have a professional Bluetooth sniffer available? 
We do provide a free Bluetooth sniffer which is good enough for most sniffing tasks, but here we need to analyze packet timing very accurately which I am unsure if the nRF Sniffer can do. 

Best regards
Torbjørn