Score:0

Ubuntu

Bluetooth can't find any device after tweaking wifi configuration

Harley

5/18/23, 4:08 PM

I've been dual booting Kubuntu and Win10. Both the Bluetooth and WiFi are fine when using from Win10. Here's my system info.

Now, after a while, WiFi signal started to drop quite frequently and also irregularly. Eventually I was forced to change the antenna settings by creating the /etc/modprobe.d/rtl8723be.conf file and appending options rtl8723be ant_sel=2 to this file. That's when the Bluetooth issue popped up. Note: setting ant_sel=1 resulted into broken WiFi.

I tried removing all previously saved devices as they couldn't able to connect. Then Bluetooth couldn't able to find any device! Tried with bluetoothctl and then, scan on, which is just laptop's own mac id. Tried removing and subsequently adding Bluetooth module with sudo rmmod btusb; sleep 5; sudo modprobe btusb. Didn't work.

Here's some relevant info; lsusb, lspci, lspci -k, sudo rfkill list all, sudo dmesg -HT | grep -i bluetooth and, sudo systemctl status bluetooth.service.

Thanks. Let me know if any other info is required. By the way, if I reset the WiFi settings to default, ie. removing the /etc/modprobe.d/rtl8723be.conf file, the Bluetooth works just fine. But in doing so, WiFi issue reappears. Now, at least, WiFi works without any hitch for last few days.

0 + 0

wireless

bluetooth

networking

realtek

20.04

heynnema

5/18/23, 5:16 PM

Are you using 2.4Ghz or 5Ghz wireless networks? What channels are set in the router? Is `bluetooth coexistence` enabled in the router?

Harley

5/19/23, 4:31 AM

I'm using a 2.4Ghz router (TP-Link TL-WR820N). By default, channel was set as Auto. I changed it to 1 while keeping the `bluetoothctl scan on` open, it immediately printed out some devices except my cellphone and Bluetooth earphone. So, I rebooted and tried scanning again and now I can't see any device. Exactly same thing happened upon changing the channel to 6 or 11. After these, I tried changing the channel width from Auto to 20MHz, still nothing. Sadly I couldn't find the the existence of `bluetooth coexistence` in my router.

heynnema

5/19/23, 1:36 PM

Did you install the rtl8723be yourself, or was it already installed when you purchased the computer?

Harley

5/19/23, 1:49 PM

Not sure what you meant exactly, but I didn't install any external bluetooth/ wifi hardware. But upon finding error similar to this one `hci0: Failed to load rtl_bt/rtl8723b_config.bin` in `dmesg`, I installed firmware from this [link](https://github.com/armbian/firmware/tree/master/rtl_bt) and bluetooth started to work. But that was **before** I modified wifi configuration.

heynnema

5/19/23, 1:51 PM

Is the rtl8723be internal or external? Internal, yes? So with the new firmware, is it all working now... without wifi mods?

Harley

5/19/23, 1:53 PM

Without WiFi mods? Yes bluetooth works just fine.

Score:1

Ubuntu

heynnema

5/18/23, 5:11 PM

In Windows

Sometimes Windows settings can mess up device configuration in Ubuntu. Do this...

boot into Windows
open the Power control panel
choose change what the power buttons do
choose change options that are unavailable
uncheck fast startup
close the Power control panel
open an administrative command prompt window
type powercfg /h off
type chkdsk /f c:
approve to run chkdsk at next reboot
reboot into Windows to let chkdsk run on drive C:

Wi-Fi

Install WiFi Analyzer on your smart phone, and determine what local WiFi channels have the least use. Set your router's Wifi to that channel... or try channels 1/6/11, as they have no overlap.

0 + 0

Harley

5/19/23, 4:15 AM

Hi @heynnema, I had to do some of these as a precaution while setting up dual boot. Anyway, I checked again, disabled the fast boot and hibernation in windows, also completed a disk check up of C: drive as you suggested. Still nothing.

Harley

5/19/23, 4:39 AM

I checked with an analyzer app, most of the routers nearby are overlapping with mine, even after switching to channel 1, 6 or 11. Anyway I finally set it to 11. But I am not sure that the issue is with router side. Because I tried connecting the laptop to my phone's hotspot/ or different WiFi connections for that matter, Bluetooth still didn't work then.

heynnema

5/19/23, 1:31 PM

@Harley Yes, there will always be some overlap, but look at the center of each channel to determine how many there are per channel. Channels 1/6/11 won't overlap... although you'll see that with 20/40 bandwidth, they will overlap nearby channels. Try two tests... 1) power off the router and see if your bluetooth can find devices, or 2) disconnect from any 2.4Ghz wireless network and see if your bluetooth can find devices.

Harley

5/19/23, 1:45 PM

Yeah, bluetooth starts to work (able to find devices and connect to earphone), almost immediately when wifi is turned off.

heynnema

5/19/23, 1:50 PM

@Harley Which test were you running? Try both tests. Report back.

Harley

5/19/23, 1:51 PM

2nd one. just completely turned off wifi connection with `nmcli radio wifi off`

heynnema

5/19/23, 1:56 PM

@Harley So I'm a little confused as to where we are. With the new BT firmware, is everything working, or is there still a wifi or BT problem? The nmcli command didn't do exactly the same as the tests I suggested. Please turn wifi back on and try my tests exactly as I requested them. Thanks.

Harley

5/19/23, 2:02 PM

My apologies. This time, I disconnected my wifi ssid (it's 2.4GHz) from the panel and bluetooth starts to work immediately.

heynnema

5/19/23, 2:07 PM

@Harley Here's what I'm trying to eliminate... 2.4Ghz wifi and bluetooth overlap in frequency... so they can interfere with each other. By changing channels in the router, or, as you did, change the 20/40 bandwidth, or powering off the router to eliminate the specific wifi and making sure that the router wasn't causing the problem. So it's still unclear... do you still have a wifi or BT problem, or did the firmware fix anything? Be specific whilst running my tests. Thanks.

Harley

5/19/23, 2:24 PM

1) I switched off the router, now laptop's not connected to any wifi network and bluetooth works (both finding and connecting to device). 2) I disconnected the laptop from my router's ssid (which is 2.4GHz). Again laptop's not connected to any wifi network. And bluetooth works. My problem is that, wifi and BT can't able to function properly at the same time. I can't use BT when connected to any wifi network. If I remove wifi mod, both of them works, but wifi disconnects randomly. Thanks.

heynnema

5/19/23, 2:35 PM

@Harley OK, thanks. Do you know if you've got a V1 or V2 router? Are you in Europe? Check your router firmware against this page... https://www.tp-link.com/in/support/download/tl-wr820n/v2/#Firmware

heynnema

5/19/23, 2:37 PM

@Harley In your wifi, are you using WPA2-AES?

Harley

5/19/23, 2:53 PM

Let us [continue this discussion in chat](https://chat.stackexchange.com/rooms/133341/discussion-between-harley-and-heynnema).

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Bluetooth can't find any device after tweaking wifi configuration

TH: บลูทูธไม่พบอุปกรณ์ใด ๆ หลังจากปรับแต่งการกำหนดค่า wifi

RO: Bluetooth nu poate găsi niciun dispozitiv după ce ați modificat configurația wifi

RU: Bluetooth не может найти какое-либо устройство после настройки конфигурации Wi-Fi

VI: Bluetooth không tìm thấy thiết bị nào sau khi chỉnh cấu hình wifi

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