Programming a fleet of Beacons

RE: Programming a fleet of Beacons

Hieu — Wed, 23 Aug 2017 08:45:57 GMT

@endnode I somehow overlooked your answer and only realized you already brought up FICR after I post mine :S

RE: Programming a fleet of Beacons

endnode — Wed, 23 Aug 2017 08:28:56 GMT

(always good to hear the same twice;)

RE: Programming a fleet of Beacons

Hieu — Wed, 23 Aug 2017 02:41:59 GMT

If you don't want to hard code anything, there are the Factory Information Configuration Registers. One of those registers store a Device Address randomly generated during the manufacturing process.

You can access that via NRF_FICR->DEVICEADDR[0] and NRF_FICR->DEVICEADDR[1]. You can read more about this Device Address here: devzone.nordicsemi.com/.../

There is also a Device ID stored in those registers, as discussed in this question. devzone.nordicsemi.com/.../

Here is a code snippet of how I use the Device Address registers in my code for unique ID.

scanrsp_manuf_data[2] = NRF_FICR->DEVICEADDR[0] & 0x000000FF;
scanrsp_manuf_data[3] = (NRF_FICR->DEVICEADDR[0] >> 8) & 0x000000FF;
scanrsp_manuf_data[4] = (NRF_FICR->DEVICEADDR[0] >> 16) & 0x000000FF;
scanrsp_manuf_data[5] = (NRF_FICR->DEVICEADDR[0] >> 24) & 0x000000FF;
scanrsp_manuf_data[6] = NRF_FICR->DEVICEADDR[1] & 0x000000FF;
scanrsp_manuf_data[7] = ((NRF_FICR->DEVICEADDR[1] | 0x0000C000) >> 8) & 0x000000FF;

RE: Programming a fleet of Beacons

endnode — Tue, 22 Aug 2017 19:42:59 GMT

I was surprised by different UUID, that wouldn't work with GATT Clients much;) If you are fine to have major minor random then either generate them on first boot (in large sample of hundreds of thousands of beacons you should arrive to pretty much equal distro;) or steal few bytes from that FICR S/N...

RE: Programming a fleet of Beacons

mstewart — Tue, 22 Aug 2017 19:28:35 GMT

I'm sorry. Same UUID, but unique major/minor, although I think this answer still answers my question.

RE: Programming a fleet of Beacons

endnode — Tue, 22 Aug 2017 19:20:12 GMT

If you want to have UUIDs really unique then yes. Alternatively you could hard-code some UUID "base" into the FW and the rest take from S/N stored in FICR area (which isn't guaranteed t be 100% unique but it's randomly generated 8-byte string and so far no one has spotted any collisions;) You can either place that string into part of 128-bit UUID directly or do some hashing/concealing before...