First–huge Thank You to all the contributors on this forum! Score one for voluntary human interaction.

I had great difficulty getting the XBox 360 wireless controllers to work; nothing went well. Not a total Linux n00b but not expert either.

First: the “retroarch.cfg” file is your best friend. If all else fails, manually editing this file to achieve correct controller mappings will solve controller problems.

Second: /opt/retropie/emulators/RetroArch/installdir/bin/retroarch-joyconfig is your other friend; it quickly maps joystick inputs to the parameters for the retroarch.cfg files. It just takes a bit of doing to get it to work; my issue was it didn’t see my controller until I had them registered properly–see below.

Third: if joyconfig doesn’t see your controller, not to worry. Go here:
https://github.com/retropie/RetroPie-Setup/wiki/Setting-up-the-XBox360-controller
And use method #3. Method #1 gave me inconsistent results; the controller would jump around between js0, js1, and js3. Joyconfig couldn’t see it half the time. And it made SNES games jumpy or slow. Method #3 consistently registers the controller. It also solved my other perplexing problem–even when method #1 properly registered the controller, and the controller worked in EmulationStation, the games couldn’t see the controller.

Fourth: Get “jstest”–as in “sudo apt-get install joystick”. Once installed, find your controller with “jstest /dev/input/jsX” where “X” is 0 to 3. When you hit the right one, you’ll have zero values for the analog sticks and “off” for the buttons. Wiggle them around, press buttons, witness the magic of an XBox 360 controller talking to Linux on a 20-dollar computer*.

Now you’ve got the XBox controller reliably and stably registered with that shell script/demon trick (method #3). You’ve got the tool to tell you where it is and what its buttons do (jstest).

Use retroarch-joyconfig to create a mapping file:
“./retroarch-joyconfig -o p1.cfg -p 1 -j 0”

Copy the text that’s generated to the end of your “/opt/retropie/configs/all/retroarch.cfg” file.

Don’t assume that just because it’s mapped it’ll work in all emulators; it won’t. You now have to map that general controller to specific console’s expectations.

Individual emulator’s retroarch.cfg files are located in /opt/retropie/configs/NameOfEmulator directories. The main one under ‘all’ is overridden by the individual emulators.

If you have issues with mis-mapped keys in a game, make note of which buttons invoke which activities; for some reason I had the hat button left mapped to the fire key in NES games. Open the /opt/retropie/configs/nes/retroarch.cfg file; note which action is mapped to the number “2” (see below). Change its mapping from “2” to “11”–the right trigger.

And so forth.

XBox button/stick numerical mappings derived from jstest:

0–D-pad Up
1–D-pad Down
2–D-pad Left
3–D-pad Right
4–A
5–B
6–X
7–Y
8–Left shoulder
9–Right shoulder
10–Left trigger
11–Right trigger
12–back
13–start
14–xbox button
15–Left stick depressed
16–Right stick depressed

* I simply can’t believe how amazing the Raspberry Pi is. I didn’t have a laptop this powerful until around 2001.