This is a Raspberry Pi running Raspbian and RetroPie.
As input control I used an Arduino Pro acting as a HID device and connected to USB of RPi. Each button is connected to the arduino, acting as a keyboard and mouse. For powering, I used a Lipo 3.7V, but as the RPi runs on 5.0V I had to use a power booster, step-up from 3.7V to 5.0V. LCD is connected to the composite video of RPi. Speaker is connected to the audio amplifier and then to the P2 audio jack of RPi.
Button 1: 5-Way Navigation Button works as keyboard arrows keys OR mouse cursor.
Button 2: Key A
Button 3: Key B
Left side – Button 4: Key Esc/Back
Left side – Switch: switch between Mouse mode / Keyboard Mode
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