Raspberry PI4 - Zexmte Bluetooth dongle - Range problem

Hello to all,

I recently bought a bluetooth dongle recommended by HA to increase the range of the raspberry PI4 ( ZEXMTE BT-505 [RTL8761BU] (Long Range)

The installation went well, the dongle is well recognized in HA (the raspberry one was disabled)
I have successfully connected my 4 sensors Mi Temperature and
Humidity Monitor v1 and Temperature and Humidity Monitor Clock

My problem, the range is always so weak (2-3m max through a wall and some more in free distance)

I find that these are extremely low values.
If I connect my sensors to my phone, I can keep the connection at more than 15m through walls every 0.5sec

Do you think these are normal measures?

As it is, I can’t use it

pi@raspberrypi:~ $ dmesg|egrep -i "blu|hci|bt"
[    1.552993] xhci_hcd 0000:01:00.0: enabling device (0140 -> 0142)
[    1.553177] xhci_hcd 0000:01:00.0: xHCI Host Controller
[    1.553225] xhci_hcd 0000:01:00.0: new USB bus registered, assigned bus number 1
[    1.558910] xhci_hcd 0000:01:00.0: hcc params 0x002841eb hci version 0x100 quirks 0x00003c0000000890
[    1.560008] xhci_hcd 0000:01:00.0: xHCI Host Controller
[    1.560052] xhci_hcd 0000:01:00.0: new USB bus registered, assigned bus number 2
[    1.560096] xhci_hcd 0000:01:00.0: Host supports USB 3.0 SuperSpeed
[    1.560597] usb usb1: Product: xHCI Host Controller
[    1.560626] usb usb1: Manufacturer: Linux 5.15.61-v7l+ xhci-hcd
[    1.562628] usb usb2: Product: xHCI Host Controller
[    1.562658] usb usb2: Manufacturer: Linux 5.15.61-v7l+ xhci-hcd
[    1.571663] sdhci: Secure Digital Host Controller Interface driver
[    1.571699] sdhci: Copyright(c) Pierre Ossman
[    1.572383] sdhci-pltfm: SDHCI platform and OF driver helper
[    1.899843] usb 1-1: new high-speed USB device number 2 using xhci_hcd
[    2.941454] mmc0: SDHCI controller on fe340000.mmc [fe340000.mmc] using ADMA
[    3.239846] usb 1-1.4: new full-speed USB device number 3 using xhci_hcd
[    3.391328] usb 1-1.4: Product: Bluetooth 5.1 Radio
[    9.619148] Bluetooth: Core ver 2.22
[    9.619280] NET: Registered PF_BLUETOOTH protocol family
[    9.619297] Bluetooth: HCI device and connection manager initialized
[    9.619326] Bluetooth: HCI socket layer initialized
[    9.619348] Bluetooth: L2CAP socket layer initialized
[    9.619389] Bluetooth: SCO socket layer initialized
[    9.863337] usbcore: registered new interface driver btusb
[    9.887562] Bluetooth: hci0: RTL: examining hci_ver=0a hci_rev=000b lmp_ver=0a lmp_subver=8761
[    9.890569] Bluetooth: hci0: RTL: rom_version status=0 version=1
[    9.890601] Bluetooth: hci0: RTL: loading rtl_bt/rtl8761bu_fw.bin
[    9.918350] Bluetooth: hci0: RTL: loading rtl_bt/rtl8761bu_config.bin
[    9.933394] Bluetooth: hci0: RTL: cfg_sz 6, total sz 27814
[   10.357616] Bluetooth: hci0: RTL: fw version 0x09a98a6b
[   11.141645] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   11.141675] Bluetooth: BNEP filters: protocol multicast
[   11.141706] Bluetooth: BNEP socket layer initialized

pi@raspberrypi:~ $ hciconfig -a
hci0:   Type: Primary  Bus: USB
        BD Address: 00:E0:43:8A:16:03  ACL MTU: 1021:6  SCO MTU: 255:12
        UP RUNNING
        RX bytes:1804 acl:0 sco:0 events:165 errors:0
        TX bytes:29501 acl:0 sco:0 commands:165 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: 'HomeAssistant'
        Class: 0x000000
        Service Classes: Unspecified
        Device Class: Miscellaneous,
        HCI Version: 5.1 (0xa)  Revision: 0x9a9
        LMP Version: 5.1 (0xa)  Subversion: 0x8a6b
        Manufacturer: Realtek Semiconductor Corporation (93)

pi@raspberrypi:~ $
pi@raspberrypi:~ $
pi@raspberrypi:~ $ bluetoothctl
Agent registered
[CHG] Controller 00:E0:43:8A:16:03 Pairable: yes
[bluetooth]# show
Controller 00:E0:43:8A:16:03 (public)
        Name: raspberrypi
        Alias: HomeAssistant
        Class: 0x00000000
        Powered: yes
        Discoverable: no
        DiscoverableTimeout: 0x000000b4
        Pairable: yes
        UUID: Generic Attribute Profile (00001801-0000-1000-8000-00805f9b34fb)
        UUID: Generic Access Profile    (00001800-0000-1000-8000-00805f9b34fb)
        UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)
        UUID: A/V Remote Control Target (0000110c-0000-1000-8000-00805f9b34fb)
        UUID: A/V Remote Control        (0000110e-0000-1000-8000-00805f9b34fb)
        UUID: Device Information        (0000180a-0000-1000-8000-00805f9b34fb)
        Modalias: usb:v1D6Bp0246d0537
        Discovering: no
        Roles: central
        Roles: peripheral
Advertising Features:
        ActiveInstances: 0x00 (0)
        SupportedInstances: 0x04 (4)
        SupportedIncludes: tx-power
        SupportedIncludes: appearance
        SupportedIncludes: local-name
        SupportedSecondaryChannels: 1M
        SupportedSecondaryChannels: 2M
        SupportedSecondaryChannels: Coded
[bluetooth]#

Thank you for your feedback and advice
Nice Day :slight_smile: