UniversalController is an Android app that connects to your RetroPie via Bluetooth. You can use it as a generic, virtual controller for the different platforms. A short list of currently supported controllers:
- SNES/RetroPie
Useful for controlling SNES games, and RetroPie itself
- Commodore 64 Keyboard
Supports all the keys (F-keys, Run/Stop etc) that one needs during use
- Commodore Amiga Keyboard
- Mouse
Useful for Amiga games (for example) that require mouse input
- Joystick
A generic touchscreen joystick (Note: To use it you have to switch the joystick in VICE to "numpad")
- Android Keyboard
Android keyboards are optimized for usability, this can be useful for writing longer text
- Intellivision
- ColecoVision
Some of the more crammed keyboards (Amiga, C64) support pinch and zoom. E.g. if a game needs repeated use of the F-keys you can zoom in on those.
This app does not replace an actual joystick or game controller, for two reasons: one, Bluetooth has an inherent latency that kills any fast-moving action game, two, when you look at the screen your hands slowly move out of position on your smartphone because there is no tactile feedback.
So, this tools is awesome for navigating through menus and stuff, and even for slow gameplay. You will not successfully play Great Giana Sisters with it.
** MAKE A BACKUP OF YOUR SYSTEM **
Seriously, this app is alpha-stage at best. It patches at least one system file (the Bluetooth config), so something could go wrong.
Ok, here's the installation procedure:
- Attach keyboard to RetroPie (this is just for installation)
- Make sure you have internet connectivity (also only for installation)
- Drop out of RetroPie by hitting F4
- On the command line:
cdgit clone https://github.com/threebrooks/UniversalControllercd UniversalController/linuxsudo ./install.sh
Hopefully the installation went well, then restart the RPi with
sudo shutdown -r now
- Go into the Bluetooth settings, select to pair a new device
- Your RetroPie should show as "retropie" (allow for a good amount of time, like a minute, and regularly hit refresh on your Bluetooth list on the phone). Pair with retropie when it shows up!
- Download the "UniversalController" app on the Google Play Store (https://play.google.com/store/apps/details?id=com.threbrooks.bluetoothkeyboard)
- In the top bar, tap on the right item (left of the Bluetooth icon) and select "retropie"
- After a few seconds, the Bluetooth icon should change to that it is connected (the one in the app, not your phone's icon. That one is annoyingly reserved for Android-native connections)
- You're ready to go! The drop-down list of platforms is to the left of the Bluetooth list
- To reiterate, the C64 and the Amiga keyboard support pinch and zoom (two fingers)
- The keys are tiny, i have a hard time hitting the right one: The C64 and Amiga keyboards support two-finger pinch and zoom
- How do i use the modifier keys? (Shift, Commodore Key etc): They are "tap to activate". So, tap Shift, then tap Run/Stop for example to do the C64 "Shift Run/Stop" combination
- The "Digital Joystick" doesn't work: That screen emits numpad keycodes for the directions. In VICE you have to switch the joystick port to "numpad" to make it work
- How do I add Intellivision/ColecoVision overlays? Connect your phone/tablet to a computer, and create a directory called "INTV"/"CoolCV". Place the overlay pictures into that directory. Next time on app start, when you push the arrows on the controller, you can switch between the overlays.
The app is located in the android/ folder of the project, it's an Android Studio project.
That's the easy one. You should start with copying maybe the Commodore 64 keyboard code and use that as a template.
Now, the way these keyboard-like controllers work is that there are two PNG files (look at the android/app/src/main/res/drawable folder): one normal picture of the keyboard (e.g. controller_c64.png) and one "mask" picture (controller_c64_mask.png) that is the same size as the normal one.
"Display" image
"Mask" image
The app only shows the Display picture, but when you touch a section of the picture, the underlying code (the "BitmapControllerView" class you inherit from does this for you) looks up the exact same image location in the Mask picture, and calls the onPixelClick() function with the RGB value of the mask image's pixel you clicked on.
If you look at the Mask picture, you see that all the buttons are yellow boxes. They are all different shades of yellow however! Each box has a different RGB value. (to make it easy in the code, they all have the same red and green value, the only thing changing is the blue value). When you create your own masking picture, write down the different RGB values and what key they map to, and then carry that over to the onPixelClick function. The good thing about this approach is that there is no limitation as to the shape of the keys, or even that they are contiguous! You can map the two Alt keys to the same color for example if you want.
So, to add another controller, create the two pictures and put them into that folder, then refer to them in the constructor of your controller class.
Two more places need to be adjusted:
- android/app/src/main/res/values/strings.xml : Add your new controller as a new string value, and also add it to the controller_init_list (this is the order displayed in the GUI)
- android/app/src/main/java/com/threbrooks/universalcontroller/FullscreenActivity.java : Add your class into that long if-then-else section
Test and debug, and then create a pull request!
That's a bit harder. You have to inherit from ControllerBaseView and build up your own layout.
I take zero responsibility for any damage this tool might do to your Android device or Raspberry Pi (I can't see how it even could, but better point it out). The tool is as-is, license is entirely and completely free. Improve, copy, modify, do whatever you like.