why are the random addresses the some?

[andy2003hunan]

hi everyone.now i am developing a project with nrf51822.i am using the PCA10000 dongle to see some information of advertising packages. i moved out and pluged in the PCA10001 many times,but the random address are the some.why?general speaking,they should be different.

[andy2003hunan]

and i want to know where is the random address from?how does it come out?

[Carles]

Hi there,

By default the SD used the "Static Random" address type as defined by the Specification in GAP 10.8.1. This means that it is a random number but static: i.e. it does not change at all, it is actually stored in flash in a special register called the FICR and loaded from there every time the SD is initialized.

You sound like you require a random private (non-resolvable) address, which is designed to change periodically. To do this, simply generate your own random number and use:

sd_ble_gap_address_set()

to set it.

Regards,

Carles

[Carles]

I am not sure I understand your question. As mentioned in my reply, the static random address is fixed random number stored in a special register in flash, the FICR.

You can set your own address every time the application boots up, effectively overriding the default address and using your own one, of the type you see fit.

[andy2003hunan]

TKS.I got it.

[Ole Morten]

Good! To help other finding and reading this question later, it would be very useful if you could accept Carles' answer. :-)