Bluetooth Passthrough issue remembering wiimotes

[SiriusVI]

Hey everyone,

getting back into Dolphin emulation after a long hiatus. Last time I used Dolphin, I had a hard time getting my original nintendo wiimotes paired via a bluetooth dongle. I'd get it to work eventually, but it was never really reliable as in: I launch Dolphin, I press 1+2 on the wiimote and it pairs. Sometimes it worked fine, sometimes it didn't work, sometimes it worked only on 2 wiimotes, but not on all 4.

I was happy to see the dolphin team developed the new bluetooth passthrough pairing mode, which sounded great, so I tried it with my bluetooth adapter. It didn't work, so I bought an adapter that the passthrough wiki said was working.

I got the UGREEN USB Bluetooth 4.0 Adapter [CSR8510] and wouldn't you know, it worked... well kind of.

You see, the initial sync works fine. I tried it in  Mario Kart. All four wiimotes pair with the bluetooth dongle. But whenever I close Mario Kart and relaunch it, only 2 wiimotes will be connected right away with the push of a button. The other two won't pair unless I resync everything from scratch.

I KNOW that the wiimotes are not to blame, because I tried switching them up. Whichever wiimote I use, the first two always pair, the other two don't.

After some research, I found that at least two people reported the same issue with the same adapter even, but the thread was closed before the issue could be resolved.

I'm referring to this thread: https://forums.dolphin-emu.org/Thread-bluetooth-passthough-dongle

To this part specifically:

"It's a bit strange, I can sync my 3 Wiimotes for the first time i.e. running Mario Kart. All runs fine.
If I stop the game and start Mario Kart again, the BT controller only connects 2 Wiimotes.

But this is game dependent!
I.e. Mario Kart 2 controllers
Smash brawl 3 controllers
Donkey Kong returns 1 controller
Mario party8 2 controller
This is reproducible"

I've tested this and can confirm it. It is game dependent. I manage to get all 4 wiimotes working though, after resyncing them. They just don't conveniently pair up correctly.

Now, do any of you guys know how this issue can be resolved? What really baffles me is that different games react differently. If all games just paired 2 wiimotes, then I'd think the adapter had some kind of limitation, but that can't be it, since some games DO pair more than 2 wiimotes and some pair even just one.

[SiriusVI]

I bought another BT adapter which was recommended by some redditors and on other forums online. It's called the Zexmte.

https://www.amazon.de/-/en/Bluetooth-Receiver-Transfer-Wireless-Keyboard/dp/B0775YF36R/ref=sr_1_4?crid=1O9HDOR0A0VYL&keywords=zexmte&qid=1642779605&s=computers&sprefix=zexmte%2Ccomputers%2C61&sr=1-4

In Mario Kart I now can reconnect 3 wiimotes, at least sometimes, so I guess it works better than the Ugreen adapter. Sadly however, The fourth wiimote won't reconnect.

In Mario Kart there is a workaround. You can go to the 4-Player Multiplayer screen and then add a wiimote by pressing + on one of the connected wiimotes. By pressing 1 and 2 on the missing wiimote, it will eventually connect. However, not all games have this function.

[SiriusVI]

Hmm, didn't think the dolphin community was this inactive ...

[mbc07]

BT Passthrough can be very finicky depending of the BT adapter used, perfect compatibility is only guaranteed when using a real Wii BT module modded to USB. Other adapters may or may not remember the pairings and there's not much you can do other than trying other adapter ¯\_(ツ)_/¯

[SiriusVI]

Hey thanks for answering. Is there a shop I can buy a modded wii BT module to USB module? I don't really wanna do that myself..

[ExtremeDude2]

There is a user that sells them here:

https://www.abbiedoobie.com/

[SiriusVI]

Thanks for the info. He doesn't seem to ship to Germany, though. I contacted him and asked for details =).

Will this adapter work exactly like on a real Wii? Will it pair and remember all my Wii motes without issue?

[ExtremeDude2]

It should, but I've not tested one myself.

https://wiki.dolphin-emu.org/index.php?title=Bluetooth_Passthrough#Adapter_test_results

[SiriusVI]

The chart on the Dolphin Wiki is not reliable. I've tested some of these, as I mentioned and the dongles don't remember my pairings, at least not if I use 4 Wii remotes.

The UGREEN dongle for example is listed in green, meaning "Fully compatible. Works well in all cases and will give the same experience as a Wii Bluetooth adapter.".

I can definitely say that it does NOT give the same experience as the Wii Bluetooth Adapter, since not all wii remotes will pair, after they are synced and the game is launched for a second time.

It might be possible that this is not caused by the BT dongle, but by Dolphin, but I don't know. This worries me, because while I am willing to pay a good deal to have an original wii BT to USB module, I really don't want to receive one just to find out that the same pairing issues remain even with the original wii BT module.

Would be great if someone could confirm that with the original BT module and Dolphin, I can sync all 4 wii remotes ONCE and then have them pair immediately after restarting the PC and Dolphin, just like it would work on a real Wii console.