BLE设备可在iOS上使用，但不能在Android上使用

Question

Here's my problem
I have an electronic lock that uses BLE, it works fine on ios(Both LightBlue & the app I made)
But on Android, after bonding with the lock(I entered the pin code 000000), I can connect to the device, but one of the Service (UUID:7570) becomes empty, and I can't read or write to any characteristic.
Also the device always gets disconnected after about 20 seconds.

This is the ScreenShot from ios

This is the ScreenShot from android (with empty Service)

Here's the log I got from nRF Connect

nRF Connect, 2018-02-07          
OHGA-ELock 60012 (68:C9:0B:15:99:0D)          
V   17:57:52.234    Connecting to 68:C9:0B:15:99:0D...          
D   17:57:52.234    gatt = device.connectGatt(autoConnect = false, TRANSPORT_LE)          
D   17:57:52.767    [Callback] Connection state changed with status: 0 and new state: CONNECTED (2)          
I   17:57:52.767    Connected to 68:C9:0B:15:99:0D          
D   17:57:52.769    wait(1600ms)          
D   17:57:52.785    [Broadcast] Action received: android.bluetooth.device.action.ACL_CONNECTED          
V   17:57:54.373    Discovering services...          
D   17:57:54.373    gatt.discoverServices()          
D   17:57:54.395    [Callback] Services discovered with status: 0          
I   17:57:54.395    Services discovered          
V   17:57:54.414    Generic Access (0x1800)          
- Device Name [R] (0x2A00)          
- Appearance [R] (0x2A01)          
- Peripheral Preferred Connection Parameters [R] (0x2A04)          
Generic Attribute (0x1801)          
Unknown Service (00007570-0000-0000-0000-000000000000)          
Device Information (0x180A)          
- System ID [R] (0x2A23)          
- Model Number String [R] (0x2A24)          
- Serial Number String [R] (0x2A25)          
- Firmware Revision String [R] (0x2A26)          
- Hardware Revision String [R] (0x2A27)          
- Software Revision String [R] (0x2A28)          
- Manufacturer Name String [R] (0x2A29)  

D   17:58:10.701    [Callback] Connection state changed with status: 8 and new state: DISCONNECTED (0)  
        E   17:58:10.701    Error 8 (0x8): GATT CONN TIMEOUT   
        I   17:58:10.701    Disconnected  
        D   17:58:10.794    [Broadcast] Action received: android.bluetooth.device.action.ACL_DISCONNECTED  

I've tested it on different Android phones with different testing apps.
Is there a chance this is an issue of the BLE device?

Please let me know if more specific details are needed.
Any help or suggestion would be appreciated. Thanks!

Answer 1

the device always gets disconnected after about 20 seconds

This is because of the supervision timeout . In Android it is hardcoded to 20 seconds during which a re-connect doesn't work. For more information to know what this 20 seconds and supervision timeout take a look here- Android BLE connection timeouts and GATT internal errors