So first let us set up Reaper to recognise the gamepad. Plug the gamepad in and Windows should immediately recognise this as a joystick or game controller. Then start up Reaper.
Select your Galy USB Joystick from the “Device” dropdown box
Select “ ” in the “Processing script” dropdown.
Ensure that the “Send as MIDI control/learn” option is checked.
That is your controller set up in Reaper. Now we need to use it to trigger Reaper to do something.
Fire up the Actions window (Options -> Actions, or just press the “?” key)
Then click the “Add” button, to create the shortcut for the selected action, which brings up this window.
Click OK and you’re done. Find the other actions and assign to the other controller buttons as required. Job done.