This page is a list of tested compatible dongles for Batocera and their tested platform. If your dongle is not listed, it doesn't mean it won't work, just that it hasn't been formally tested yet.
In general, unbranded “clone” dongles, ones that don't explicitly state as supporting Bluetooth Low Energy (BLE) and BT 5.0 have the lowest chance of working. Branded dongles, with support for 4.0 or 2.0 Bluetooth, that explicitly state that they support BLE have the highest chance of working. Of course, there's always a chance that the BT dongle will/won't work irrelevant of these qualifications. With unbranded ones, there's a chance that they just don't have the specifications they list anyway (just because it says it has the same chipset as a tested dongle may not actually guarantee that or that it will work, but it will have a higher chance than one with a different chipset altogether).
If you were looking to troubleshoot your wireless dongle instead, check out both the Wi-Fi and Bluetooth sections on the troubleshooting page respectively.
If you know of another model that is not listed here, please let the moderators on Discord know, or drop a note on the forum. Thank you!
Here is the list of PCI-E cards that have been tested with Batocera.
This list is more tentative, as obviously there are too many PCI-E cards to properly test them all. It's best to assume that all modularly designed PCI-E network cards work out of the box, with the only exception being bleeding-edge cards or ones that use brand new technologies.
A list of Linux-compatible (not necessarily Batocera-compatible, but should be) Intel PCI-E cards can be found at https://www.intel.ca/content/www/ca/en/support/articles/000005511/wireless.html
Main chip: Intel AX210 or AX211.
These dongles are interesting because they let you use Wi-Fi and Bluetooth with a same dongle. If you have many USB ports it's not important, but on OGA where there is only one, it's the best choice. Don't forget you can play two players if plug a second controller on your OGA (via USB or supported BT dongle).
Main chip: RTL8723BU - BT4.0 dongle adapter, 150Mbps wireless WiFi network LAN card + Bluetooth V4.0 adapter for laptop desktop PC (working channels: 1-14)
Sometimes the integrated Wi-Fi chip embedded on a Raspberry Pi SBC isn't powerful enough for a sustainable connection, or its performance can be severely diminished by a case, in particular with metallic cases.
Audio driver support in Linux is usually much more straightforward than wifi and BT adapters. But, in case you need a cheap USB audio dongle, to replace a failing audio component on a motherboard, or if you want to separate the sound of the ball rolling on the playfoeld from the backglass music and sounds effets in Visual Pinball X you can get this USB audio dongle that has been verified on PC: