Real Atari 2600 Joysticks are necessary for a truly authentic feel when using an emulator. The UJOY interface allows to connect one Atari Joystick to a standard USB port.
The Atari joystick is a very simple device. Just 5 switches directly connected to a female DB9 connector. We used a Silicon Laboratories EFM8UB1 USB microcontroller as the bridge.
The schematics is quite simple. The Silicon Labs MCU is highly integrated and optimized for the task and does not require any external components (save a few decoupling capacitors) to implement a USB device.
The PCB is shaped to fit into a standard DB9 plastic shell to provide a practical and easy to find case for the device.
The device is compliant with the USB HID specification allowing driverless plug and play operation in all major operating systems.
