There are many ways to control PPSSPP, and a lot of settings to configure so you can find your optimal setup.
Rebind PSP controls to keyboard, game pad and virtual buttons.
Lets you set up deadzones and stuff to adjust the response of the analog stick.
This sets at what "depth" that analog trigger inputs will count as clicks.
If this is checked, keys like the Windows key, alt key etc can be used as normal. If you instead want to map those, uncheck this option.
If this is checked, gamepads will only function when the PPSSPP window has focus.
Enable to use on-screen touch controls. This is mainly useful on devices such as phones and tablets with no or too few hardware buttons, but with a good touch screen.
Used to move on-screen buttons to custom positions.
Hold down a button and drag the button to the desired location. Then click on Back to save changes.
To Reset changes, press the Reset button.
Lets you map what happens when you touch the background (outside the PSP buttons) and drag.
Just configures the look of the on-screen buttons.
Used to change the opacity of buttons. An opacity of 0 is completely transparent. Opacity of 100 is fully opaque
After this number of seconds of inactivity, touch-screen buttons are hidden. This is nice when playing on the gamepad or watching long cutscenes.
This is known as "touch gliding" in some other emulators. This lets you press multiple buttons with a single finger, by pressing the first one and then sliding over to other buttons - the first one will be kept held if this setting is on.
This moves the analog stick center to where you touched.
A more flexible alternative to this is to disable the left stick in "Edit touch control layout", then go into Gesture mapping and on the left side, use the option "Enable analog stick gesture".
Does what it says.
Ignores the Windows key when the emulator is running.
If you bind a keyboard key to the "Analog limiter" control, it will reduce the magnitude of the analog stick response - so you can walk instead of run, for example. This setting controls the amount by which the magnitude is multiplied to reduce it.
If you map the "Rapid fire" input, all buttons will repeat at this rate (in number of frames).
If this is enabled, the device will vibrate every time a button is pressed. Useful of mobile devices for tactile feedback.
This category contains some generally useful settings if you want to use the mouse as an input (which isn't really recommended, PSP games are not made to be mouse-controlled).