bluetooth: Can't connect to BBC micro:bit BLE device |
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Issue descriptionGoogle Chrome 53.0.2785.13 (Official Build) dev (64-bit) Revision f88481b907e2fff8fd02eaf4043e66d86ff7bfb9-refs/branch-heads/2785@{#70} Platform 8530.11.0 (Official Build) dev-channel link What steps will reproduce the problem? (1) Go to Chrome OS Settings / Bluetooth (2) Click "Add a device" button, search for your BBC micro:bit BLE device waiting to be paired (3) Select it and click "Connect" button What is the expected output? Pairing process for BBC micro:bit BLE device should start. What do you see instead? An error. See screenshots below. Here are helpful btmon logs: @ Discovering: 0x00 (7) < HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7 [hci0] 311.882239 Type: Passive (0x00) Interval: 60.000 msec (0x0060) Window: 30.000 msec (0x0030) Own address type: Public (0x00) Filter policy: Ignore not in white list (0x01) > HCI Event: Command Complete (0x0e) plen 4 [hci0] 311.882737 LE Set Scan Parameters (0x08|0x000b) ncmd 1 Status: Success (0x00) < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0] 311.882796 Scanning: Enabled (0x01) Filter duplicates: Enabled (0x01) > HCI Event: Command Complete (0x0e) plen 4 [hci0] 311.883740 LE Set Scan Enable (0x08|0x000c) ncmd 1 Status: Success (0x00) > HCI Event: LE Meta Event (0x3e) plen 38 [hci0] 312.507822 LE Advertising Report (0x02) Num reports: 1 Event type: Connectable undirected - ADV_IND (0x00) Address type: Random (0x01) Address: DA:01:DB:0B:60:C6 (Static) Data length: 26 Flags: 0x06 LE General Discoverable Mode BR/EDR Not Supported Name (complete): BBC micro:bit [vagap] RSSI: -85 dBm (0xab) < HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2 [hci0] 312.507937 Scanning: Disabled (0x00) Filter duplicates: Disabled (0x00) > HCI Event: Command Complete (0x0e) plen 4 [hci0] 312.508778 LE Set Scan Enable (0x08|0x000c) ncmd 1 Status: Success (0x00) < HCI Command: LE Create Connection (0x08|0x000d) plen 25 [hci0] 312.508873 Scan interval: 60.000 msec (0x0060) Scan window: 60.000 msec (0x0060) Filter policy: White list is not used (0x00) Peer address type: Random (0x01) Peer address: DA:01:DB:0B:60:C6 (Static) Own address type: Public (0x00) Min connection interval: 50.00 msec (0x0028) Max connection interval: 70.00 msec (0x0038) Connection latency: 0x0000 Supervision timeout: 420 msec (0x002a) Min connection length: 0.000 msec (0x0000) Max connection length: 0.000 msec (0x0000) > HCI Event: Command Status (0x0f) plen 4 [hci0] 312.509746 LE Create Connection (0x08|0x000d) ncmd 1 Status: Success (0x00) > HCI Event: LE Meta Event (0x3e) plen 19 [hci0] 313.540725 LE Connection Complete (0x01) Status: Success (0x00) Handle: 32 Role: Master (0x00) Peer address type: Random (0x01) Peer address: DA:01:DB:0B:60:C6 (Static) Connection interval: 67.50 msec (0x0036) Connection latency: 0.00 msec (0x0000) Supervision timeout: 420 msec (0x002a) Master clock accuracy: 0x00 < HCI Command: LE Read Remote Used Features (0x08|0x0016) plen 2 [hci0] 313.540881 Handle: 32 @ Device Connected: DA:01:DB:0B:60:C6 (2) flags 0x0000 02 01 06 16 09 42 42 43 20 6d 69 63 72 6f 3a 62 .....BBC micro:b 69 74 20 5b 76 61 67 61 70 5d it [vagap] > HCI Event: Command Status (0x0f) plen 4 [hci0] 313.541727 LE Read Remote Used Features (0x08|0x0016) ncmd 1 Status: Success (0x00) > HCI Event: LE Meta Event (0x3e) plen 12 [hci0] 313.889786 LE Read Remote Used Features (0x04) Status: Success (0x00) Handle: 32 Features: 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00 LE Encryption < ACL Data TX: Handle 32 flags 0x00 dlen 11 [hci0] 313.889864 SMP: Pairing Request (0x01) len 6 IO capability: KeyboardDisplay (0x04) OOB data: Authentication data not present (0x00) Authentication requirement: Bonding, MITM, SC, No Keypresses (0x0d) Max encryption key size: 16 Initiator key distribution: EncKey Sign LinkKey (0x0d) Responder key distribution: EncKey IdKey Sign LinkKey (0x0f) = bluetoothd: No cache for DA:01:DB:0B:60:C6 313.900219 < ACL Data TX: Handle 32 flags 0x00 dlen 7 [hci0] 313.900180 ATT: Exchange MTU Request (0x02) len 2 Client RX MTU: 517 > ACL Data RX: Handle 32 flags 0x02 dlen 11 [hci0] 314.293776 SMP: Pairing Response (0x02) len 6 IO capability: DisplayOnly (0x00) OOB data: Authentication data not present (0x00) Authentication requirement: Bonding, MITM, Legacy, No Keypresses (0x05) Max encryption key size: 16 Initiator key distribution: <none> (0x00) Responder key distribution: EncKey IdKey (0x03) > HCI Event: Number of Completed Packets (0x13) plen 5 [hci0] 314.293810 Num handles: 1 Handle: 32 Count: 1 @ User Passkey Request: DA:01:DB:0B:60:C6 (2) > HCI Event: Number of Completed Packets (0x13) plen 5 [hci0] 314.294734 Num handles: 1 Handle: 32 Count: 1 > ACL Data RX: Handle 32 flags 0x02 dlen 7 [hci0] 314.698140 ATT: Exchange MTU Response (0x03) len 2 Server RX MTU: 23 < ACL Data TX: Handle 32 flags 0x00 dlen 11 [hci0] 314.698530 ATT: Read By Group Type Request (0x10) len 6 Handle range: 0x0001-0xffff Attribute group type: Primary Service (0x2800) > HCI Event: Number of Completed Packets (0x13) plen 5 [hci0] 314.833763 Num handles: 1 Handle: 32 Count: 1 > ACL Data RX: Handle 32 flags 0x02 dlen 18 [hci0] 315.103264 ATT: Read By Group Type Response (0x11) len 13 Attribute data length: 6 Attribute group list: 2 entries Handle range: 0x0001-0x0007 UUID: Generic Access Profile (0x1800) Handle range: 0x0008-0x000b UUID: Generic Attribute Profile (0x1801) < ACL Data TX: Handle 32 flags 0x00 dlen 11 [hci0] 315.103561 ATT: Read By Group Type Request (0x10) len 6 Handle range: 0x000c-0xffff Attribute group type: Primary Service (0x2800) > ACL Data RX: Handle 32 flags 0x02 dlen 26 [hci0] 315.508821 ATT: Read By Group Type Response (0x11) len 21 Attribute data length: 20 Attribute group list: 1 entry Handle range: 0x000c-0x000e UUID: Unknown (e95d93b0-251d-470a-a062-fa1922dfa9a8) > HCI Event: Number of Completed Packets (0x13) plen 5 [hci0] 315.508854 Num handles: 1 Handle: 32 Count: 1 < ACL Data TX: Handle 32 flags 0x00 dlen 11 [hci0] 315.509226 ATT: Read By Group Type Request (0x10) len 6 Handle range: 0x000f-0xffff Attribute group type: Primary Service (0x2800) > HCI Event: Vendor (0xff) plen 7 [hci0] 315.981812 82 12 95 40 10 36 59 ...@.6Y > HCI Event: Disconnect Complete (0x05) plen 4 [hci0] 315.982749 Status: Success (0x00) Handle: 32 Reason: Connection Timeout (0x08) @ Device Disconnected: DA:01:DB:0B:60:C6 (2) reason 1
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Jul 20 2016
,
Jul 20 2016
For info, here's what says https://github.com/lancaster-university/microbit-docs/blob/82a2aca45ce3317e7f901903e8fac7667e208987/docs/ble/profile.md#bluetooth-security: micro:bit uses standard Bluetooth security. Bluetooth defines a series of optional security features of which the following are used for micro:bit: 1. Pairing with passkey and MITM protection 2. White Listing 3. Encrypted link for operations involving most characteristics
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Jul 20 2016
After having a discussion with josephsih@, we find the suspicion in the last part btmon logs in issue summary,
> HCI Event: Number of Completed Packets (0x13) plen 5 [hci0] 315.508854
Num handles: 1
Handle: 32
Count: 1
< ACL Data TX: Handle 32 flags 0x00 dlen 11 [hci0] 315.509226
ATT: Read By Group Type Request (0x10) len 6
Handle range: 0x000f-0xffff
Attribute group type: Primary Service (0x2800)
> HCI Event: Vendor (0xff) plen 7 [hci0] 315.981812
82 12 95 40 10 36 59 ...@.6Y
> HCI Event: Disconnect Complete (0x05) plen 4 [hci0] 315.982749
Status: Success (0x00)
Handle: 32
Reason: Connection Timeout (0x08)
The time difference between the outgoing packet and the disconnection packet is 472.586 ms, which is greater than the agreed supervision timeout(420 ms), so it's likely that host decided to disconnect from the peripheral which is considered out-of-range. And we saw the similar issue on PocketLab(http://www.thepocketlab.com/). To see if this is the cause, I will upload a test patch to change the supervision timeout to 2 seconds where pairing should be more stable.
Note that we recently find that the failure rate of pairing is about 3~5% which comes from 1000 tests in the isolated chamber, and we will have further investigation to improve the pairing.
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Jul 20 2016
Do you want a trace of Android?
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Jul 21 2016
Android supervision timeout can be a clue of our assumption.
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Jul 21 2017
This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue. Sorry for the inconvenience if the bug really should have been left as Available. If you change it back, also remove the "Hotlist-Recharge-Cold" label. For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot
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Sep 20 2017
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Apr 19 2018
The supervision timeout has been changed to 2 seconds (https://chromium-review.googlesource.com/441506).
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Jul 12
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Comment 1 by fbeaufort@chromium.org
, Jul 20 2016116 KB
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