BLE white list : Can I set wild card for white list?

[Won Huh]

Hi, I just started to develop a new project with nRF52840 and I've been trying to understand about white listing feature of BLE.

As I need white list to skip unknown device's scanning or connection trial, I want to save white list to peripherals in advance like in a manufacturing process so that only customer devices (central) can scan and try to connect.

However, according to nordic SDK, max count is 8 which is not so enough for many central devices and they may change their central devices.

So I wonder if t is possible to set some sort of wild card to cover a group of various devices in white list rather than using specific device address.

Thank you.

Won 

[tesc]

Hi,

No, there is no "wildcard" functionality. Whitelist is implemented as mandated by the Bluetooth specification.

On the central you can decide what peripherals to attempt to connect to based on the advertisement. Either based on what BLE services are advertised, or on manufacturer specific data.

On the peripheral you can for instance implement some sort of authorization in order to get access to the BLE services, and also dropping the connection if the central fails to get authorized within reasonable time.

Regards,
Terje

[Won Huh]

Hi Terje,

Thank you for answering.

I have one more quesion, so when you say implementing some sort of authorization, does it mean paring algorithm like Passkey display or Out of Band?

Regard,

Won

[tesc]

Hi,

It depends on what is the use case. Pairing (with or without bonding) is the mechanism in BLE for the user to connect two devices to each other. So if the end user (or someone else) sets up those connections (or guides the process) then yes, that is what you can do. We already support paring and bonding in our SoftDevice and with our SDK, and there are numerous examples in the SDK using this functionality.

If you need the devices to be connected from factory then you can for instance program them with existing bonds. If the device needs to know about more other devices than what will fit in flash, then you need to implement some sort of other authorization that enables the devices to trust each other when setting up the connection. I definitely recommend using what is already in BLE (i.e. pairing and bonding.)

Regards,
Terje