extract pair key

[icondev]

Can the pairing code be extracted from memory via JLink during production in order to print a pair code decal for a product without a display?

I know it shows up on the tablet in an application or can be printed to logs but is it known statically before programming the application code?

[Einar Thorsrud]

Hi,

What exactly do you refer to by "pair key". Is it a 6 digit Bluetooth pass key? I will assume so for now. SDK examples that use passkey generate them on demand, but you can use a static pass key as well. Then you would typically generate that in your production script and program it to a special location in flash (could be in UICR or somewhere else which fits you, as long as it is in a fixed place you can easily program separately for all devices in production). Then you can also print this.

If this is not what you are after, then please explain what you mean by "pair key".

[icondev]

We are using a 4 digit pairing code. Talking to our BLE library guy, he said he thinks it is generated from the mac address. Is there a calculation that can be used to get the code from the Mac address so we don't need to rebuild the library with a special mode?

[Einar Thorsrud]

There is no standard concept of a 4 digit pairing code in BLE nor in our SDKs so I cannot say exactly what it is or how you use it. I am sure it would be possible to do something sensible in production, but I would need to know more details in order to make suggestions.

[icondev]

I was able to find the way to read the mac address with JLink and found that we are generating the pair code from a custom checksum. This is our own calculation and not from the SDK so it is my misunderstanding. Thanks for your quick responses.