Unable to use some UUIDs when trying to extend DFU service (undocumented API)

RE: Unable to use some UUIDs when trying to extend DFU service (undocumented API)

Bjørn Kvaale — Thu, 22 Mar 2018 07:38:42 GMT

You are correct. In the infocenter, buttonless dfu without bonds characteristic is set to 0x0003 (0x0004 for buttonless dfu with bonds characteristic). It might be that these characteristics are hardcoded in the nrf connect app & therefore they are set as native Nordic characteristics. I will mention your recommendation about documenting extending a service.

RE: Unable to use some UUIDs when trying to extend DFU service (undocumented API)

Andy — Tue, 20 Mar 2018 09:31:21 GMT

I just found out that UUID 0x0003 is used by the BLE DFU module for the Buttonless DFU characteristic. However, that characteristic is not included in the bootloader and I have no idea why does the nRF Connect app wants to do something with it during the DFU process.

It might be a good idea to document that if you want to extend the service, you shouldn't use that UUID for compatibility reasons.

RE: Unable to use some UUIDs when trying to extend DFU service (undocumented API)

Andy — Tue, 20 Mar 2018 09:16:50 GMT

I don't think so, the UUIDs use Nordic's base UUID, i.e. 0x8EC90003-F315-4F60-9FB8-838830DAEA50

RE: Unable to use some UUIDs when trying to extend DFU service (undocumented API)

Bjørn Kvaale — Tue, 20 Mar 2018 07:26:54 GMT

It could be the protocol identifiers RFCOMM & TCP UUIDs mentioned in Table 1.

RE: Unable to use some UUIDs when trying to extend DFU service (undocumented API)

Andy — Mon, 19 Mar 2018 13:19:29 GMT

No, I just found the ones that worked and just kept going with my work. But those UUIDs (0x0003 and 0x0004) were recognized by the Android app as "native" Nordic characteristics.

RE: Unable to use some UUIDs when trying to extend DFU service (undocumented API)

Bjørn Kvaale — Mon, 19 Mar 2018 13:17:42 GMT

I have checked the bootloader_secure_ble example in SDK 13.1 & it seems there aren't any defined UUIDs that use 0x0003 & 0x0004. Have you tested any other values that do not work? What about 0x0005 or 0x0006? Do these values work?