Issue connection for "Google find my device"

[yousseflxn]

Hello

Environment:

• nRF Connect SDK Version: v2.7.0-rc2
• Board: nRF52840 DK
• Operating System: Windows 10
• Android Phones: Samsung S20 (Android 13) / POCO F3 (Android 13)

Description:

I am using the locator_tag example in the nRF Connect SDK to test the "Google Find My Device" feature. The project was built with the default MODEL_ID and ANTI_SPOOFING_KEY.

When running the project on the nRF52840 DK, I receive the connection pop-up from the "Google Find My Device" application and start the connection process.

However, I consistently encounter an issue connecting from the app (see attached picture).

I have tested with both my phones, and the "Find My Device" feature is active and functioning on both devices with different accounts. Despite this, the issue persists.

Below are the logs from the nRF52840 DK, which seem to be normal, with no warnings or errors except for the "Key discarded (timeout)" message.

nRF52840 DK Logs:

I: Settings loaded
I: FMDN: setting battery level to 100 %
I: FMDN level: Normal
I: DULT level: Full
I: Fast Pair: RPA expired
I: Fast Pair: setting RPA timeout to 775 [s]
I: Fast Pair: prepared the advertising set
D: FMDN State: TX power set to 0 [dBm]
D: FMDN State: enabled
I: DULT enabled
D: Fast Pair is enabled
I: FMDN: state changed to unprovisioned
I: Fast Pair: advertising in the discoverable mode
I: Sample has started
I: Connected
D: Personalized Name is empty
D: Personalized Name was not notified (Key-based Pairing)
D: Key-based Pairing write: res=80 conn=0x200022b8
D: Account Key stored
I: Fast Pair: Account Key write
I: Fast Pair: automatically switched to non-discoverable advertising mode
I: Fast Pair: advertising inactive due to an active connection
D: Account Key write: res=16 conn=0x200022b8
D: Beacon Actions GATT Read Request
D: Beacon Actions: challenge-response enabled for the next write:
D: f5 e0 1c a0 4a e5 77 14 |....J.w.
D: Beacon Actions read: res=9 conn=0x200022b8
I: Beacon Actions CCCD write, handle: 0, value: 0x0001
D: Beacon Actions GATT Write Request:
D: 01 08 6e 59 a1 7d 29 c1 |..nY.}).
D: 13 41 |.A
D: Beacon Actions: consuming random nonce read operation
D: Beacon Actions response:
D: 01 09 13 bb 57 8c 8b 79 |....W..y
D: c4 d7 02 |...
D: Beacon Actions write: res=10 conn=0x200022b8
I: Beacon Actions CCCD write, handle: 0, value: 0x0000
I: Key discarded (timeout)
I: Performing reset to factory settings...
D: FMDN State: disabled
I: DULT reset completed
D: Fast Pair is disabled
I: Fast Pair: automatically switched to disabled advertising mode
I: Fast Pair: advertising inactive due to an active connection
I: Factory Reset: resetting Bluetooth identity within the factory reset
I: Fast Pair: RPA expired
I: Fast Pair: the last timeout has occurred 309 [s] ago
I: Fast Pair: setting RPA timeout to 751 [s]
I: Fast Pair: prepared the advertising set
D: FMDN State: TX power set to 0 [dBm]
D: FMDN State: enabled
I: DULT enabled
D: Fast Pair is enabled
I: Reset to factory settings has completed
I: FMDN: state changed to unprovisioned
I: Please press a button to put the device in the Fast Pair discoverable advertising mode after a reset to factory settings
I: Disconnected (reason 22)
I: Fast Pair: advertising in the disabled mode
D: FMDN Clock: storing the last value: 600 [s]

Questions:

1. Is the behavior observed in the nRF52 logs normal when connecting to a new Android phone?
2. Could the issue be related to using the default debug MODEL_ID and ANTI_SPOOFING_KEY provided in the sample?

Thank you for your assistance.

Youssef

[luckbear]

Hi，Youssef

I would like to ask what ID you are using. After I use 0x4A436B，fast pair cannot get the device. Has it been refined?

[yousseflxn]

Hi

For me, I also used model id: 0x4A436B, I always got Issue Connecting pop-up

[Amanda Hsieh]

luckbear said:

Can Fast Pair recognize FMDN only after submitting the device registration application?

Yes, please contact Google. 

luckbear said:

Does enabling the FMDN function affect the connection of the fast pair?

It affects this sample Bluetooth Fast Pair: Locator tag. Please see the note in the Testing. 

luckbear said:

Can the ID provided by Nordic Demo be used by the developer if his account is not registered in fmdn?

No, please see the note in the Testing. 

[luckbear]

Thank you very much for your detailed answer。

[Wayne]

Hi,

I'm having trouble getting a Model ID.  For my device registration application I just put the locator_tag debug/demo Model ID.  This I assume is plainly wrong.

In the NearbyConsole when I use 'Add Series' it wants a company name but I don't have a Bluetooth Assigned number and I assume I can't just select Nordic Semiconductor ASA?

Any help would be appreciated. 

Thanks

Wayne

[Amanda Hsieh]

Hi, 

I don't think it would get accepted by Google as the Nordic debug model is registered under our company name (Nordic Semi). There will be a mismatch between their company name as seen on the device proposal form and their model ID.

Please get in touch with Google for the registration issue. 

-Amanda H.

[Wayne]

Hi Amanda,

Thanks for answering at the weekend.

Should I be able to use the Nordic locator_tag sample as-is (without creating or registering my own model id) if I've done all the phone setup steps (Find My Device app installed, display debug info, google service notifications) and have flashed the unmodified locator_tag sample firmware?

I'm starting to think that maybe the locator_tag sample needs a note saying it's for only developers that are legally entitled to use a Bluetooth SIG registered company name.

For example:

When I bring my phone close tot he nRF the FMD half screen popup appears then fter selecting 'Connect' and accepting the T&C's there is a connection error.  In the Android 11 LogCat

"SpotPairing - Model ID isn't certified"

The "NCS Locator Tag" name is appearing in my list of FMD remembered devices.  This is perhaps indicative of the Nordic debug model ID not being associated with my gmail account?  Or are Debug Model ID's allowed for any account?

I shall also reach out to Google.   

Thanks for your time,

All the best

Wayne

[Amanda Hsieh]

Hi,

Wayne said:

Should I be able to use the Nordic locator_tag sample as-is (without creating or registering my own model id) if I've done all the phone setup steps (Find My Device app installed, display debug info, google service notifications) and have flashed the unmodified locator_tag sample firmware?

Yes, as long as the test Android device uses a primary email account that is on Google’s email allow list for the FMDN feature. 

Wayne said:

This is perhaps indicative of the Nordic debug model ID not being associated with my gmail account?  Or are Debug Model ID's allowed for any account?

The doc said:

You can either register your own device or use the debug Model ID and Anti-Spoofing Public/Private Key pair obtained by Nordic Semiconductor for development purposes.

Did you modify anything of the Locator tag sample? If so, please test with the unmodified sample. If not, Could you create a new support case and upload the completed log via Toolbar -> Insert -> code? Also, provide the case link or number. I will pick up it.

-Amanda H.