TP Link UB500 (Rtl8761b) can't find any device in pairing mode

I currently use CoreElec 19.5 RC2 on an Odroid N2+ and try to get my new bluetooth dongle to work.

The dongle is the UB500 from TP-Link which has the Realtek Rtl8761. This chipset is already supported and also the bluetooth stick itself is recognized by the system but can’t find any bluetooth device when i start the scan.

Here some outputs:

hciconfig-a:

Kodi-Wohnzimmer:~ # hciconfig -a
hci0:	Type: Primary  Bus: USB
	BD Address: E8:48:B8:C8:20:00  ACL MTU: 1021:6  SCO MTU: 255:12
	UP RUNNING 
	RX bytes:1422 acl:0 sco:0 events:96 errors:0
	TX bytes:4389 acl:0 sco:0 commands:96 errors:0
	Features: 0xff 0xff 0xff 0xfe 0xdb 0xfd 0x7b 0x87
	Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 
	Link policy: RSWITCH HOLD SNIFF PARK 
	Link mode: SLAVE ACCEPT 
	Name: 'Kodi-Wohnzimmer'
	Class: 0x0c0000
	Service Classes: Rendering, Capturing
	Device Class: Miscellaneous, 
	HCI Version: 5.1 (0xa)  Revision: 0xb
	LMP Version: 5.1 (0xa)  Subversion: 0x8761
	Manufacturer: Realtek Semiconductor Corporation (93)

lsusb:

Kodi-Wohnzimmer:~ # lsusb
Bus 002 Device 002: ID 05e3:0620 Genesys Logic, Inc. USB3.1 Hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 2357:0604 TP-Link TP-Link UB500 Adapter
Bus 001 Device 002: ID 05e3:0610 Genesys Logic, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

lsusb -s:

Kodi-Wohnzimmer:~ # lsusb -s 001:003 -v

Bus 001 Device 003: ID 2357:0604 TP-Link TP-Link UB500 Adapter
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass          224 Wireless
  bDeviceSubClass         1 Radio Frequency
  bDeviceProtocol         1 Bluetooth
  bMaxPacketSize0        64
  idVendor           0x2357 TP-Link
  idProduct          0x0604 
  bcdDevice            2.00
  iManufacturer           1  
  iProduct                2 TP-Link UB500 Adapter
  iSerial                 3 E848B8C82000
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength       0x00b1
    bNumInterfaces          2
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0xe0
      Self Powered
      Remote Wakeup
    MaxPower              500mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           3
      bInterfaceClass       224 Wireless
      bInterfaceSubClass      1 Radio Frequency
      bInterfaceProtocol      1 Bluetooth
      iInterface              4 Bluetooth Radio

lsmod bt:

Kodi-Wohnzimmer:~ # lsmod | grep bt
btusb                  45056  0
btrtl                  16384  1 btusb
btbcm                  16384  1 btusb
btintel                24576  1 btusb
bluetooth             425984  27 btrtl,btintel,btbcm,btusb

if i restart the bluetooth service i only get this output:

Kodi-Wohnzimmer:~ # dmesg -c
Kodi-Wohnzimmer:~ # systemctl restart bluetooth.service
Kodi-Wohnzimmer:~ # dmesg
[ 3040.909404@1]- proc: unrecognized mount option "hidepid=invisible" or missing value
Kodi-Wohnzimmer:~ # 

with bluetoothctl I can start the scan but it can’t find any device which is currently in pairing mode:

Kodi-Wohnzimmer:~ # bluetoothctl
Agent registered
[CHG] Controller E8:48:B8:C8:20:00 Pairable: yes
[bluetooth]# show
Controller E8:48:B8:C8:20:00 (public)
	Name: Kodi-Wohnzimmer
	Alias: Kodi-Wohnzimmer
	Class: 0x000c0000
	Powered: yes
	Discoverable: no
	DiscoverableTimeout: 0x000000b4
	Pairable: yes
	UUID: A/V Remote Control        (0000110e-0000-1000-8000-00805f9b34fb)
	UUID: Audio Source              (0000110a-0000-1000-8000-00805f9b34fb)
	UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)
	UUID: Audio Sink                (0000110b-0000-1000-8000-00805f9b34fb)
	UUID: A/V Remote Control Target (0000110c-0000-1000-8000-00805f9b34fb)
	UUID: Generic Access Profile    (00001800-0000-1000-8000-00805f9b34fb)
	UUID: Generic Attribute Profile (00001801-0000-1000-8000-00805f9b34fb)
	UUID: Device Information        (0000180a-0000-1000-8000-00805f9b34fb)
	Modalias: usb:v1D6Bp0246d0538
	Discovering: no
	Roles: central
	Roles: peripheral
Advertising Features:
	ActiveInstances: 0x00 (0)
	SupportedInstances: 0x05 (5)
	SupportedIncludes: tx-power
	SupportedIncludes: appearance
	SupportedIncludes: local-name
[bluetooth]# scan on
Discovery started
[CHG] Controller E8:48:B8:C8:20:00 Discovering: yes
[bluetooth]# 

Any clue what can be the issue here?

I don’t know if this guide is helpful in this case: GitHub - tedboudros/tplink-ub500-linux-patch-guide: A guide on how to get the UB500 bluetooth dongle working on <5.16 linux kernels!

No, everything is already correct in kernel.

What you get by command scan on in bluetoothctl?

I get no reply (list devices does only show itself as controller). So it seems, that the bluetooth stack ist working but it does not see any device.

I was also wondering, that i don’t get the hci_uart entry in the lsmod output. I don’t know if that is important to get bluetooth running well.

Support for this dongle was only added in the latest version of CE, however it was not advertised in the changelog. I have the N2+ and this dongle and it works fine.

Ah, thanks for the info. Do you mean CE 20 alpha 3?

I can confirm, that the dongle is working fine in CE 20 alpha 3 :slight_smile:

So the case can be closed :slight_smile:

Thanks all

As I have the trouble, that some important Addons currently not working for me within CE20/alpha3 (Plex and LUNA), is there a way to move over the support for the dongle to 19.5 rc2?