nRF52840 bonded but no connection

Hi,

I have my device based on the nRF52840, we have manufactured some equipments and we have created our own application to manage connection. Everything is working fine.

When our device is first connected to a smartphone, the smartphone asks for a key to stablish bonding: we manage this through our application.

Nevertheless, if a user bonds the device usign smartphone base system (through bluetooth icon provided by the system) then:

- Device remains in a 'connected' state

- If we open then the application, device does not appear as available as it is not advertising.

Only way to recover the device is just to switch off bluetooth or unbond it from the smartphone.

The question is: which is the best way to manage this? how can we avoid to have the device in this 'connected' state when following the above described steps?

Best regards,

Dani.

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0 user8164 over 4 years ago

Hi,

When the device has been connected to the phone, but not visible from your app, is it visible in nRF Connect on that same phone? I suspect it will be possible if using the correct API, or that there may be some restrictions on certain device types for the given smartphone OS and version.

We may be able to provide better pointers if you provide information about what smart phone and OS, and what kind of device (is it for instance a HID device?)

Regards,
Terje
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0 user8164 over 4 years ago

Hi,

When the device has been connected to the phone, but not visible from your app, is it visible in nRF Connect on that same phone? I suspect it will be possible if using the correct API, or that there may be some restrictions on certain device types for the given smartphone OS and version.

We may be able to provide better pointers if you provide information about what smart phone and OS, and what kind of device (is it for instance a HID device?)

Regards,
Terje
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0 user3586 over 4 years ago in reply to user8164

Hi,

The device is not visible from nRF Connect, neither from any other type of Smartphone (tested with different Android and IoS devices).

Having the device 'connected' to the first smartphone, the device is seen again from any other device when bluetooth is switched off in the first smartphone.

It seems as the device remains blindy 'connected'
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0 user8164 over 4 years ago in reply to user3586

Hi,

So what you see, is that the device seems to be connected to the phone in the background, but not visible in your app?

Do you have a sniffer trace from when this happens?

Regards,
Terje
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0 user3586 over 4 years ago in reply to user8164

Hi,

I have done the following procedure:

- Device switched on (advertising)

- Android Bluetooth is used to bond the device to my smartphone: device seems to remain 'connected'

- Application is launched (our application or nrF Connect): device can not be seen

- Then, bluetooth in the smartphone is switched off --> Device starts advertising again

I have tried to save sniffer log using a developement board together with WireShark, but Wireshark is not catching more frames once device has been bonded to the smartphone. Any suggesiton?

Regards,

Dani.
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