Once RetroPie resets connect the Gamepad controller by tapping the center “U” button. When this is done EmulationStation will “see” your controller. If a configuration window does not pop up then connect a different controller or keyboard and hit “start” to pull up the necessary menu.
The initial configuration only allows the gamepad controller to work properly with EmulationStation, and not the actual emulators. This issue is easily solved with a few further steps. This is not a difficult process, but it does take some work, so bare with me, it will all be worth it in the end.
The next part of the process involves configuring the controller in RetroArch. Because the Gamepad controller is not mapped properly by EmulationStation this is easiest if you have a keyboard or another controller connected so that you can easily navigate through the RetroArch UI.
First access “RetroArch” through the “RetroPie” menu in EmulationStation.
Next choose “Settings” and then “Configuration” and change the “Save Configuration on Exit” to “on”. Once this is done, back out to the previous menu.
Next choose “Input”
Next choose “Input User 1 Binds
Next use your keyboard/extra controller to help you navigate (until the binds have been set up) and change the inputs as desired. Make sure that the “Device Index” is set to “Game Controller (#1)”. I also like to change the “Device Type” to “Retropad w/ Analog” and the “Analog to Digital Type” to “Left Analog” as this allows me to use the left analog stick as a d-pad. You will need the button numbers later, so make sure to write down how RetroArch numbers the buttons. After configuring the controller make sure to also choose “Save Autoconfig” and then back out to the previous screen
Next choose “Input Hotkey Binds” I don’t do much here, but I highly suggest setting the “Save State” and “Load State” to a button. The hotkeys are used by pressing the desired hotkey plus the enable hotkey at the same time. The hotkeys (including the enable hotkey button) will need some further configuration, but that will happen in another area, for now it is enough to set this part up.
Finally back out to the main RetroArch menu and choose “Quit RetroArch”
After starting MAME hit tab on computer keyboard select general configurations and selected the Input General options. This will configure the setup and apply it to all games.
Then going through each button and joystick movement and mapping this to my control panel.