Unique Device ID

[Dave]

I have a radio board using a NRF51822 with a custom radio protocol. I need a unique identifier, ideally 24bit, 32bit but be acceptable.

I notice in the parameters there is:

Device ID 64bit unique ID for each unit. DEVICEID[0] DEVICEID[1]

Device address bit 64bit. DEVICEADDR[0] DEVICEADDR[1]

I cant think of a mathematical method of reducing the number of bits and presume there isnt a way (64bit to 24bit or 32bit)?

I presume the DEVICEID is unique for every chip? Unless the device ID is made of different fields that can be split?

[Paul]

You need to look at your application for the "Unique ID". If all the ID's got uploaded to a database and linked to a server, You can always put a extra column to fix it, or even download it back to fix permanently. I still think the hash idea would work. If it is online, then server can assign an ID back. If it is offline application, I don't see too many reasons to really really have a "Unique" ID.

[Tom]

No ID in the chip is guaranteed to be unique, as they are all randomly generated in production of the chip.

If true uniqueness is required, writing a unique serial number (or similar) to a constant or NVM and recompiling for each unit is a possible solution. But this is time consuming for large quantities. Any other suggestions? We are considering using uVision5 to program.