Observed Advertising Name length limit (~22 characters) in DFU mode

[RSerna]

Hi

I`m working with an nRF52833.

I've observed that when the module enters DFU mode, the Bluetooth advertising name seems to be limited to around 22 characters.

If I set a longer name, it exits DFU mode.

I'm not sure if this is an intentional limit or a side effect of how the DFU advertising data is structured. Could someone clarify the reason for this behavior?

Thanks.

RSerna

[Vidar Berg]

Hello,

The maximum payload for the primary advertisement packet is 31 octets, and the first 9 bytes are used to hold the advertising flags and the UUID of the DFU service. Note that if you use buttonless DFU the advertisment name in dfu mode will normally not be visible to the user.

Best regards,

Vidar