Get the nRF52840 factory-set Bluetooth Address

[brianreinhold]

This is a very simple question:

According to the documentation, each dongle is assigned a Bluetooth Address at the factory using some random number generation algorithm that remains with the IC permanently. However, I can set the Bluetooth Address to something else (which I need to do and I change it often as I am writing a test suite). But I need some unique identifier of the nRF52840 dongle. The factory assigned Bluetooth address would be an ideal candidate, but I do not know how to get that address once I have set the address to something else.

Is there a way to get the factory generated Bluetooth Address OR is there another way I can (programmatically) get a unique identifier of a given dongle?

Note that I am using the pc-ble-driver and thus need to use the sd_* methods.

[Ivan Herrera]

I think this is what you're looking for: https://devzone.nordicsemi.com/f/nordic-q-a/14152/what-is-the-difference-between-the-deviceid-and-deviceaddr/54079#54079

To summarize: NRF_FICR->DEVICEADDR[] will get you the factory-set Bluetooth address. NRF_FICR->DEVICEID[] is also a unique identifier you could use.

[brianreinhold]

Looks promising. But I am not sure if it applies to the nRF52840 dongle. If it does, would you know what method I should call to get either of these values or is the NFR_FICR one of the defined structs I can always read?

It does not appear that such a struct is available to me; A global search does not find any of these fields. The struct might be different for the dongle.

[Ivan Herrera]

It applies to the nRF52840. The NFR_FICR struct should be defined as long as you include "nrf.h" in your project. Below are some examples as to how to read these values:

NRF_LOG_INFO("DEVICEADDR0: %08X\n", NRF_FICR->DEVICEADDR[0]);
NRF_LOG_INFO("DEVICEADDR1: %08X\n", NRF_FICR->DEVICEADDR[1]);

NRF_LOG_INFO("DEVICEID0: %08X\n", NRF_FICR->DEVICEID[0]);
NRF_LOG_INFO("DEVICEID1: %08X\n", NRF_FICR->DEVICEID[1]);

[brianreinhold]

Got burned!

This is all that is in my nrf.h file

#ifndef NRF_H__
#define NRF_H__

/* Empty file for SDK compatibility */

#endif // NRF_H__

I don't get it. I am using the pc-ble-driver, but I do not understand why that information is omitted. Maybe I can go to the standard SDK  and grab the include file. I might have to remove stuff from it but I do not understand the rationale ... Nordic has some explaining to do!

[Ivan Herrera]

Woops, I totally missed the fact that you were using the pc-ble-driver. Copying code over from the standard SDK wont work because the registers need to be accessed on the device itself. Could you read and store the address before you manipulate it? 

[brianreinhold]

You are correct. That works. I made the assumption that the dongle would keep the address I set. björn spokile confirmed that it is not the case. So I can do as you suggest. That also means I no longer need to check the address against my set addess; I have to set it every time.