RE: fast pair connects but fails to add to find my device

Hieu — Tue, 01 Apr 2025 14:02:24 GMT

Unfortunately, I cannot reproduce the issue with NCS v2.9.1. At the bottom is my log where the device can be added to my phone successfully, and I also tested the play sound feature successfully.

We are unfortunately out of clue now. Can I ask you to test with NCS v2.9.1, and if that still failed, test with another phone?

*** Booting NCS locator tag v2.9.1 - unknown commit ***
*** Using nRF Connect SDK v2.9.1-60d0d6c8d42d ***
*** Using Zephyr OS v3.7.99-ca954a6216c9 ***
I: Starting Bluetooth Fast Pair locator tag example
I: DFU: Firmware version: 2.9.1+0
I: 3 Sectors of 4096 bytes
I: alloc wra: 0, f00
I: data wra: 0, 108
I: SoftDevice Controller build revision: 
I: 79 a3 10 be e6 80 b7 e9 |y.......
I: a3 ba cc a9 fc 08 66 12 |......f.
I: 90 cf 45 a9             |..E.    
I: HW Platform: Nordic Semiconductor (0x0002)
I: HW Variant: nRF52x (0x0002)
I: Firmware: Standard Bluetooth controller (0x00) Version 121.4259 Build 3078678206
I: No ID address. App must call settings_load()
I: Bluetooth initialized
I: Identity[0]: CF:62:58:24:0A:53 (random)
I: Identity[1]: CA:D4:09:FF:C5:F7 (random)
I: HCI: version 6.0 (0x0e) revision 0x109a, manufacturer 0x0059
I: LMP: version 6.0 (0x0e) subver 0x109a
I: Settings loaded
I: FMDN: setting battery level to 100 %
I:      FMDN level: Normal
I:      DULT level: Full
D: FMDN State: TX power set to 0 [dBm]
D: FMDN State: enabled
D: Motion detector is not running: owner nearby
I: DULT enabled
D: Fast Pair is enabled
I: Fast Pair: prepared the advertising set
I: Fast Pair: fp_adv module enabled
I: Fast Pair: RPA expired
I: Fast Pair: setting RPA timeout to 762 [s]
I: Sample has started
I: FMDN: state changed to unprovisioned
I: Fast Pair: advertising request from trigger "ui": enable
I: Fast Pair: advertising: enabling
I: Fast Pair: advertising in the discoverable mode
I: Connected
D: Key-based Pairing write: res=80 conn=0x20002a28
D: Account Key stored
I: Fast Pair: Account Key write
I: Fast Pair: advertising request from trigger "fmdn_provisioning": enable
I: Fast Pair: advertising: enabling
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=0x20002a28
D: Beacon Actions GATT Read Request
D: Beacon Actions: challenge-response enabled for the next write:
D: d8 98 18 d9 b6 ef 99 6a |.......j
D: Beacon Actions read: res=9 conn=0x20002a28
I: Beacon Actions CCCD write, handle: 0, value: 0x0001
D: Beacon Actions GATT Write Request:
D: 01 08 2e f7 1d 4a 87 2a |.....J.*
D: 78 c8                   |x.      
D: Beacon Actions: consuming random nonce read operation
D: Beacon Actions response:
D: 01 09 3c 99 12 b6 61 6d |..<...am
D: 6f f7 02                |o..     
D: Beacon Actions write: res=10 conn=0x20002a28
I: Beacon Actions CCCD write, handle: 0, value: 0x0000
I: Disconnected (reason 19)
I: Fast Pair: advertising in the non-discoverable mode
I: Connected
D: Beacon Actions GATT Read Request
D: Beacon Actions: challenge-response enabled for the next write:
D: 36 1a ec 6d 5b ab cd 5e |6..m[..^
D: Beacon Actions read: res=9 conn=0x20002a28
I: Beacon Actions CCCD write, handle: 0, value: 0x0001
D: Beacon Actions GATT Write Request:
D: 01 08 5d e6 44 49 e7 73 |..].DI.s
D: 1a 03                   |..      
D: Beacon Actions: consuming random nonce read operation
D: Beacon Actions response:
D: 01 09 ae 78 06 45 5c c9 |...x.E\.
D: 1a 24 02                |.$.     
D: Beacon Actions write: res=10 conn=0x20002a28
I: Beacon Actions CCCD write, handle: 0, value: 0x0000
I: Beacon Actions CCCD write, handle: 0, value: 0x0001
D: Beacon Actions GATT Read Request
D: Beacon Actions: challenge-response enabled for the next write:
D: 43 12 b7 4f 04 6d be 8d |C..O.m..
D: Beacon Actions read: res=9 conn=0x20002a28
D: Beacon Actions GATT Write Request:
D: 01 08 34 1d 62 4e ca ab |..4.bN..
D: a6 99                   |..      
D: Beacon Actions: consuming random nonce read operation
D: Beacon Actions response:
D: 01 09 03 1c a7 3a ce 2f |.....:./
D: 76 0e 02                |v..     
D: Beacon Actions write: res=10 conn=0x20002a28
D: Beacon Actions GATT Read Request
D: Beacon Actions: challenge-response enabled for the next write:
D: 78 7d d8 a7 eb 12 d9 40 |x}.....@
D: Beacon Actions read: res=9 conn=0x20002a28
D: Beacon Actions GATT Write Request:
D: 00 08 14 d9 6d ed 84 c1 |....m...
D: 7c 87                   ||.      
D: Beacon Actions: consuming random nonce read operation
D: Beacon Actions: Beacon Parameters Read request: setting response TX power to -15 [dBm] encoded as 0xF1
D: FMDN Clock: reading the last value: 8 [s]
D: Beacon Actions response:
D: 00 18 c8 7d ea a5 41 e1 |...}..A.
D: bb 8f 29 1c b1 56 b4 b1 |..)..V..
D: ea 4b 6b ad bf ac 7f ba |.Kk.....
D: c3 80                   |..      
I: FMDN: clock information synchronized with the authenticated Bluetooth peer
D: Beacon Actions write: res=10 conn=0x20002a28
D: Beacon Actions GATT Read Request
D: Beacon Actions: challenge-response enabled for the next write:
D: 8e 26 73 93 e5 ed 50 58 |.&s...PX
D: Beacon Actions read: res=9 conn=0x20002a28
D: Beacon Actions GATT Write Request:
D: 02 28 da da a8 42 32 89 |.(...B2.
D: 97 91 61 98 43 c0 88 35 |..a.C..5
D: 27 88 b8 c8 67 eb b6 d3 |'...g...
D: bb 67 dc 19 c2 f2 fa 02 |.g......
D: 4e 48 d0 8f d3 9d a0 ae |NH......
D: bf 2e                   |..      
D: Beacon Actions: consuming random nonce read operation
I: FMDN: state changed to provisioned
I: Fast Pair: advertising request from trigger "fmdn_provisioning": disable
I: Fast Pair: advertising request from trigger "ui": disable
I: Fast Pair: advertising: disabling
I: Fast Pair: automatically switched to disabled advertising mode
I: Fast Pair: advertising inactive due to an active connection
D: FMDN State: RPA expired
D: FMDN Clock: reading the last value: 13 [s]
D: FMDN State: calculating new rotation time: 1011 s + 12 s
D: FMDN Clock: reading the last value: 13 [s]
D: EID seed data:
D: ff ff ff ff ff ff ff ff |........
D: ff ff ff 0a 00 00 00 00 |........
D: 00 00 00 00 00 00 00 00 |........
D: 00 00 00 0a 00 00 00 00 |........
D: EIK:
D: de a3 d2 a3 11 5f 7e 46 |....._~F
D: 99 05 f9 76 d3 be c1 4e |...v...N
D: 1f 62 39 8f 6f 0e e0 e4 |.b9.o...
D: 67 8e a5 bc 9f 5b 13 91 |g....[..
D: Encrypted EID seed data:
D: b3 42 fa 56 93 a3 59 15 |.B.V..Y.
D: 3d ab 40 58 12 f7 41 f7 |=.@X..A.
D: c7 1f e0 e5 b4 b9 82 be |........
D: 58 47 a6 9e b7 f8 9d d6 |XG......
D: EID:
D: 4a ad 60 f4 fb 00 eb d6 |J.`.....
D: 92 44 ae 99 8a ca ed 5c |.D.....\
D: 80 bd 2e 23             |...#    
D: FMDN State: Hashed Flags byte:
D:      Bitmask:        0x02
D:      Hash:           0x3B
D:      Final value:    0x39
D: FMDN State: FMDN Frame type: 0x40
D: FMDN State: rotating advertising payload
D: FMDN State: next rotation in 1023 [s]
I: Fast Pair: RPA expired
I: Fast Pair: the last timeout has occurred 13 [s] ago
D: FMDN State: forcing advertising payload rotation
D: FMDN State: advertising started
D: FMDN State: Successful provisioning of the EIK
D: Beacon Actions response:
D: 02 08 c8 f4 15 2e 8c 42 |.......B
D: f5 73                   |.s      
D: Beacon Actions write: res=42 conn=0x20002a28
I: Beacon Actions CCCD write, handle: 0, value: 0x0000
I: Disconnected (reason 19)
I: Fast Pair: advertising in the disabled mode
I: Connected
D: FMDN State: peer connected
D: FMDN State: advertising started
I: Beacon Actions CCCD write, handle: 0, value: 0x0001
D: Beacon Actions GATT Read Request
D: Beacon Actions: challenge-response enabled for the next write:
D: 0c b0 b7 a9 cc 0d 2c 78 |......,x
D: Beacon Actions read: res=9 conn=0x20002af8
D: Beacon Actions GATT Write Request:
D: 05 0c 1b 9d c4 96 d0 fd |........
D: bd e1 ff 02 58 00       |....X.  
D: Beacon Actions: consuming random nonce read operation
I: FMDN: starting ringing action with the following parameters:
I:      Source:         Bluetooth GATT FMDN
I:      Components:     Right=active, Left=active, Case=active (BM=0xFF)
I:      Timeout:        600 [ds]
I:      Volume:         Default (0x00)
D: Beacon Actions response:
D: 05 0c 45 ab 7c 88 e5 b8 |..E.|...
D: 10 e0 00 07 02 58       |.....X  
D: Beacon Actions write: res=14 conn=0x20002af8
D: Beacon Actions GATT Read Request
D: Beacon Actions: challenge-response enabled for the next write:
D: 45 01 d4 52 b0 d3 38 97 |E..R..8.
D: Beacon Actions read: res=9 conn=0x20002af8
D: Beacon Actions GATT Write Request:
D: 05 0c 01 3f 32 b2 40 7d |...?2.@}
D: a7 61 00 00 00 00       |.a....  
D: Beacon Actions: consuming random nonce read operation
I: FMDN: stopping the ringing action on GATT request
I:      Source: Bluetooth GATT FMDN
D: Beacon Actions response:
D: 05 0c 37 33 8d 44 46 fe |..73.DF.
D: e2 a3 04 00 00 00       |......  
D: Beacon Actions write: res=14 conn=0x20002af8
I: Beacon Actions CCCD write, handle: 0, value: 0x0000
I: Disconnected (reason 19)

RE: fast pair connects but fails to add to find my device

Hieu — Fri, 28 Mar 2025 14:46:08 GMT

It was a little odd to me that you are using the v2.9-branch instead of a fixed release. However, I checked the difference and there shouldn't be any impactful change between v2.9.1 and the current v2.9-branch head.

I will try to reproduce and follow up with you in 1-2 working days.

RE: fast pair connects but fails to add to find my device

andrew-identita — Thu, 27 Mar 2025 21:25:20 GMT

This was a standard installation ... literally following the instructions you listed. when I say I am using the v2.9-branch, it just means that I'm using that specific branch (checking out the specific branch as described in the instructions).

Building the firmware and flashing it was literally just navigating to nrf/samples/bluetooth/fast_pair/locator_tag and then running west zephyr-export, west build -b nrf52840dk/nrf52840 (or west build -b nrf54l15dk/nrf54l15/cpuapp for the nRF54L15 dev board) and then west flash.

I'm pretty sure I'm not doing anything weird to build the code.

RE: fast pair connects but fails to add to find my device

Hieu — Thu, 27 Mar 2025 21:20:30 GMT

Hi andrew-identita,

[quote user=""]I am using Zephyr 2.9.0 with the sdk-nrf repo v2.9-branch checked out.[/quote]

This is a little strange description of an SDK. How did you install this?

Since this is about an unmodified sample, I would like to reproduce and test this myself, but I am missing some prerequisites. Could you please try again with a specific release of the nRF Connect SDK? There are a few ways to install it, described here: Installation.

Hieu