We are using SDK 3.1.1 and nrf52DK with our own Model ID and anti-spoofing key from Google.
When flashing the Locator Tag example to the board, a half sheet notification is shown on the phone (Google Pixel 6 with Android 16) and provisioning is successful. The device is shown in the Google Find Hub app.
However, when we try the "Provisioning for non-owner" test in the Eddystone test set (configured for devices that do not create bonding during pairing) of the Google Fast Pair Validator (FPV) app, the test fails. The test was started both with the device unprovisioned via the Find Hub app and reset (turned off then on), as well as with the device freshly flashed. The tester app was running on Google Pixel 6 with Android 16 and OnePlus 3 with Android 9.
When starting the test, everything works as expected at first. Upon booting the DUT is put into advertising/pairing mode by pressing button 1. An account key is written, then the phone disconnects as planned. The FPV app then suggests to put the device back into pairing mode, which usually happens by pressing button 1. But the DUT refuses to enter pairing mode, since an Account Key has been written to the non-volatile storage (as can be seen in l.97 in Log 1). The test fails because the DUT cannot be discovered. The only other solution I found to put the device back into pairing mode is to restart the device. It then looses the saved account key and advertises again. But now the FPV app is trying to provision with another account key, which the DUT recognizes as its owner account key. So the test fails, since the DUT is supposed to remember the previous actual owner account key, such that any other account key can be reported as non-owner.
The question is: How can the DUT be put into advertising mode after having received an account key?
Log 1 (trying to put the device back into pairing mode via button 1)
*** Booting NCS locator tag v3.1.1-107a3c48bbbb *** *** Using nRF Connect SDK v3.1.1-e2a97fe2578a *** *** Using Zephyr OS v4.1.99-ff8f0c579eeb *** I: Starting Bluetooth Fast Pair locator tag sample 3.1.1 I: 2 Sectors of 4096 bytes I: alloc wra: 1, c58 I: data wra: 1, 490 I: SoftDevice Controller build revision: I: fc de 41 eb a2 d1 42 24 |..A...B$ I: 00 b5 f8 57 9f ac 9d 9e |...W.... I: aa c9 b4 34 |...4 I: HW Platform: Nordic Semiconductor (0x0002) I: HW Variant: nRF52x (0x0002) I: Firmware: Standard Bluetooth controller (0x00) Version 252.16862 Build 1121034987 I: No ID address. App must call settings_load() I: Bluetooth initialized I: HCI transport: SDC I: Identity[0]: DE:92:EC:DD:B8:EA (random) I: Identity[1]: F2:AE:B2:6F:36:76 (random) I: HCI: version 6.1 (0x0f) revision 0x1069, manufacturer 0x0059 I: LMP: version 6.1 (0x0f) subver 0x1069 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 Adv Manager: prepared the advertising set I: Fast Pair Adv Manager: RPA expired I: Fast Pair Adv Manager: RPA rotation in the inactive advertising state I: Fast Pair Adv Manager: setting RPA timeout to 753 [s] I: Fast Pair Adv Manager: module enabled I: Performing reset to factory settings... I: Fast Pair Adv Manager: module disabled D: FMDN State: advertising stopped D: FMDN State: disabled I: DULT reset completed D: Fast Pair is disabled I: Sample has startedI: Factory Reset: resetting Bluetooth identity within the factory reset 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 Adv Manager: prepared the advertising set I: Fast Pair Adv Manager: RPA expired I: Fast Pair Adv Manager: RPA rotation in the inactive advertising state I: Fast Pair Adv Manager: the last timeout has occurred 0 [s] ago I: Fast Pair Adv Manager: setting RPA timeout to 769 [s] I: Fast Pair Adv Manager: module enabled I: Reset to factory settings has completed I: The device has been reset to factory settings I: Please press a button to put the device in the Fast Pair discoverable advertising mode I: Fast Pair Adv Manager: advertising request from trigger "pairing_mode": enable D: Fast Pair Adv Manager: set pairing mode to true D: Fast Pair Adv Manager: set RPA rotation suspended to true I: Fast Pair Adv Manager: triggers state change to: active I: Fast Pair Adv Manager: advertising in the discoverable mode I: Fast Pair Adv Manager: connected to 75:87:DB:09:20:3C (random) W: Notify name not supported (KBP request) D: Key-based Pairing write: res=80 conn=0x20002088 D: Confirmed passkey D: Passkey write: res=16 conn=0x20002088 I: FMDN: connection authenticated using the Bluetooth bond: 0x20002088 I: Fast Pair Adv Manager: security changed: 75:87:DB:09:20:3C (random) level 4 D: Bonding complete D: Account Key stored I: Fast Pair Adv Manager: advertising request from trigger "fmdn_provisioning": enable I: Fast Pair: Account Key write I: Fast Pair Adv Manager: advertising request from trigger "pairing_mode": disable D: Fast Pair Adv Manager: set pairing mode to false D: Account Key write: res=16 conn=0x20002088 I: Fast Pair Adv Manager: disconnected from D4:3A:2C:8B:12:03 (public) (reason 19) I: Fast Pair Adv Manager: advertising in the not-discoverable mode I: Fast Pair Adv Manager: connected to D4:3A:2C:8B:12:03 (public) 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: 0e f4 82 78 78 2e e8 89 |...xx... D: Beacon Actions read: res=9 conn=0x20002088 D: Beacon Actions GATT Write Request: D: 01 08 1b 80 73 bc 5e 9f |....s.^. D: 35 45 |5E D: Beacon Actions: consuming random nonce read operation D: Beacon Actions response: D: 01 09 da 45 63 bb 5c e4 |...Ec.\. D: 59 da 02 |Y.. I: FMDN: connection authenticated using Beacon Actions command: 0x20002088 D: Beacon Actions write: res=10 conn=0x20002088 I: Beacon Actions CCCD write, handle: 0, value: 0x0000 I: Fast Pair Adv Manager: disconnected from D4:3A:2C:8B:12:03 (public) (reason 19) I: Fast Pair Adv Manager: advertising in the not-discoverable mode I: Fast Pair: pairing mode change is not available when the Account Key is in the NVM storage
Log 2 (restarted the device for the second part of the FPV app test)
*** Booting NCS locator tag v3.1.1-107a3c48bbbb *** *** Using nRF Connect SDK v3.1.1-e2a97fe2578a *** *** Using Zephyr OS v4.1.99-ff8f0c579eeb *** I: Starting Bluetooth Fast Pair locator tag sample 3.1.1 I: 2 Sectors of 4096 bytes I: alloc wra: 1, b88 I: data wra: 1, 59c I: SoftDevice Controller build revision: I: fc de 41 eb a2 d1 42 24 |..A...B$ I: 00 b5 f8 57 9f ac 9d 9e |...W.... I: aa c9 b4 34 |...4 I: HW Platform: Nordic Semiconductor (0x0002) I: HW Variant: nRF52x (0x0002) I: Firmware: Standard Bluetooth controller (0x00) Version 252.16862 Build 1121034987 I: No ID address. App must call settings_load() I: Bluetooth initialized I: HCI transport: SDC I: Identity[0]: DE:92:EC:DD:B8:EA (random) I: Identity[1]: F1:6F:4D:D5:05:9D (random) I: HCI: version 6.1 (0x0f) revision 0x1069, manufacturer 0x0059 I: LMP: version 6.1 (0x0f) subver 0x1069 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 Adv Manager: prepared the advertising set I: Fast Pair Adv Manager: RPA expired I: Fast Pair Adv Manager: RPA rotation in the inactive advertising state I: Fast Pair Adv Manager: setting RPA timeout to 749 [s] I: Fast Pair Adv Manager: module enabled I: Performing reset to factory settings... I: Fast Pair Adv Manager: module disabled D: FMDN State: advertising stopped D: FMDN State: disabled I: DULT reset completed D: Fast Pair is disabled I: Sample has startedI: Factory Reset: resetting Bluetooth identity within the factory reset 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 Adv Manager: prepared the advertising set I: Fast Pair Adv Manager: RPA expired I: Fast Pair Adv Manager: RPA rotation in the inactive advertising state I: Fast Pair Adv Manager: the last timeout has occurred 0 [s] ago I: Fast Pair Adv Manager: setting RPA timeout to 751 [s] I: Fast Pair Adv Manager: module enabled I: Reset to factory settings has completed I: The device has been reset to factory settings I: Please press a button to put the device in the Fast Pair discoverable advertising mode I: Fast Pair Adv Manager: advertising request from trigger "pairing_mode": enable D: Fast Pair Adv Manager: set pairing mode to true D: Fast Pair Adv Manager: set RPA rotation suspended to true I: Fast Pair Adv Manager: triggers state change to: active I: Fast Pair Adv Manager: advertising in the discoverable mode I: Fast Pair Adv Manager: connected to 75:87:DB:09:20:3C (random) W: Notify name not supported (KBP request) D: Key-based Pairing write: res=80 conn=0x20002088 D: Confirmed passkey D: Passkey write: res=16 conn=0x20002088 I: FMDN: connection authenticated using the Bluetooth bond: 0x20002088 I: Fast Pair Adv Manager: security changed: 75:87:DB:09:20:3C (random) level 4 D: Bonding complete D: Account Key stored I: Fast Pair Adv Manager: advertising request from trigger "fmdn_provisioning": enable I: Fast Pair: Account Key write I: Fast Pair Adv Manager: advertising request from trigger "pairing_mode": disable D: Fast Pair Adv Manager: set pairing mode to false D: Account Key write: res=16 conn=0x20002088 I: Fast Pair Adv Manager: disconnected from D4:3A:2C:8B:12:03 (public) (reason 19) I: Fast Pair Adv Manager: advertising in the not-discoverable mode I: Fast Pair Adv Manager: connected to D4:3A:2C:8B:12:03 (public) I: FMDN: connection authenticated using the Bluetooth bond: 0x20002088 I: Fast Pair Adv Manager: security changed: D4:3A:2C:8B:12:03 (public) level 4 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: 29 13 89 ae 3a 31 d1 b1 |)...:1.. D: Beacon Actions read: res=9 conn=0x20002088 D: Beacon Actions GATT Write Request: D: 01 08 4f a0 70 b0 78 7e |..O.p.x~ D: a8 e2 |.. D: Beacon Actions: consuming random nonce read operation D: Beacon Actions response: D: 01 09 84 4b b0 94 f9 2e |...K.... D: d3 33 02 |.3. I: FMDN: connection authenticated using Beacon Actions command: 0x20002088 D: Beacon Actions write: res=10 conn=0x20002088 I: Beacon Actions CCCD write, handle: 0, value: 0x0000 I: Fast Pair Adv Manager: disconnected from D4:3A:2C:8B:12:03 (public) (reason 19) I: Fast Pair Adv Manager: advertising in the not-discoverable mode
FPV app screenshot (after restarting the device to enter pairing mode)
