nRF51822 - ID

[Jose Xavier]

Hello,

There is any unique ID per chip that we can use? On my application I'm able to add and remove devices from network, each network consist on 5 to 10 devices. I'm planing to product 100 units, will I need to program a different id code to identify each chip?

thank you

[endnode]

Hi Xavier,

Have you read the nRF51 Reference Manual (UICR and FICR chapters)? You will find the answers there (or you can see other posts on this forum such as: devzone.nordicsemi.com/.../ ). Basically you have 8-byte ID burned into the chip and additional register area which can hold some diversified ID at the programming stage.

Cheers Jan

[Susheel Nuguru]

The Chip ID is not guarenteed to be unique. These numbers are set in production and should be random numbers (FIPS compliant).

devzone.nordicsemi.com/.../

[John]

Reminds me of a comment I saw in code that generated keys into a hash table and didn't check for collisions: "What are the odds?"

[Susheel Nuguru]

This are 64bit DeviceID, the odds of collision are fairly small, but non zero. If this is something very important for your design, you can manage this easily in your production by using nrfjprog command line tool.

[Jose Xavier]

thank you all, I think it is ok as per kit it will be using 5 to 6 tags and if there is a collision is it possible to change the tag.