Add info for DDGO P&P

README.md

@@ -8,6 +8,7 @@ Here you will find a collection of technical information for the various control
 - [Serial port controllers](serial/README.md)
 - [USB controllers](usb/README.md)
 - [Nintendo Wii controllers](wii/README.md)
+- [Standalone controllers](standalone/README.md)
 - [Software compatibility (WIP)](compatibility/README.md)
 
 ## GitHub repository

standalone/README.md

@@ -0,0 +1,15 @@
+## Standalone controllers
+
+The information in this section applies to the following controllers:
+
+- Densha de GO! Plug and Play
+
+This controller is different from traditional controllers in the sense that it contains the game (an improved version of Densha de GO! Final) and does not connect to a PC or console. Externally, it looks similar to a TCPP-20009, except it does not include a pedal connection. Internally, it contains an ARM board running Linux. It requires a micro USB cable for power and a HDMI cable for video output.
+
+The micro USB port supports USB OTG with a powered adapter and is used by Taito to install software updates.
+
+It is possible to update the Linux kernel on the board to enable USB gadget mode and emulate traditional controllers, such as the DGOC-44U. This makes it possible to control other software. You can find more information [here](https://github.com/GMMan/dengo-plug-and-play-controller).
+
+## Acknowledgements
+
+Big thanks to [GMMan](https://github.com/GMMan), who has done research on this controller and developed several software modifications.