The power switch functionality allows you to turn on and off the power to the Raspberry Pi with a toggle switch (A toggle switch is not part of the ControlBlock). The ControlBlock comes with a USB Micro socket. You can optionally solder a USB-B socket to the ControlBlock, if you need a larger connector for your project (A USB-B socket is not included in the package). Any toggle switch can be connected to the ControlBlock, which allows you the biggest flexibility for your project. The power status of the Raspberry Pi can be indicated via an LED that can be connected to male pin headers.
The GPIO pins can be accessed from the Raspberry Pi via the SPI interface. The ControlBlock makes it very easy to connect arcade controllers for up to two players. The open-source driver for the ControlBlock can be configured for various controller types. It supports, e.g., arcade controllers that are mapped to game pad devices, as well as a mapping to a MAME keyboard configuration. The ControlBlock also supports, e.g., the polling of SNES and NES controllers so that it provides the functionality of the RetroPie GPIO Adapter.
You can find an article with a detailed description of the ControlBlock, getting started information and various demo videos here. The ControlBlock comes fully assembled.
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