Uniqueness of HWID on nRF5340

RE: Uniqueness of HWID on nRF5340

Einar Thorsrud — Mon, 10 Feb 2025 08:11:33 GMT

Which HW ID are you using? Have you set it explicitly yourself, or can you check the .config? If you are using HW_ID_LIBRARY_SOURCE_DEVICE_ID which should be default, can you double check that the value you get match wat you get from the DEVICEID registers? (note that the library gives you a string representation, and not the raw value).

RE: Uniqueness of HWID on nRF5340

neo_here — Sat, 08 Feb 2025 01:49:27 GMT

Yes, just caught the typo

RE: Uniqueness of HWID on nRF5340

Emil Lenngren — Fri, 07 Feb 2025 19:57:39 GMT

Do you mean 16 bytes?

RE: Uniqueness of HWID on nRF5340

neo_here — Fri, 07 Feb 2025 19:16:40 GMT

Hey yes, we use the the HW_ID_LEN provided by hw_id.h

We're also trying to figure out if it might be process error instead as well, but wanted to know about the chances of seeing collisions.

RE: Uniqueness of HWID on nRF5340

Einar Thorsrud — Fri, 07 Feb 2025 13:03:11 GMT

Hi,

The hardware ID comes from the DEVICEID in FICR, and is 64 bit that is randomly generated in prodcution. It is not guaranteed to be unique, but given the size of the number you should normally never see collisions. Do you use the full 64 bit when you see collisions?