Custom Firmware: Hack Steam Puck to Emulate Console Controllers

The quest for the perfect controller often involves compromise. Valve’s excellent Steam Controller offers great functionality within the Steam ecosystem, but for hardcore enthusiasts, a nagging limitation persists: native XInput support is missing. That is where things get interesting, because dedicated hardware hackers have found a way to bypass the software limitations and unlock true cross-platform freedom.

Enter OpenPuck, a stunning piece of open-source ingenuity engineered by enthusiast Safijari. This DIY project transforms an existing Steam Controller into a versatile, multi-platform gamepad capable of emulating Xbox, PlayStation, and Nintendo layouts in real-time—all without needing the restrictive Steam Input software running.

OpenPuck is more than just a simple accessory; it is a custom firmware solution built around an open-source microcontroller. This system intercepts raw data from the standard controller and translates it directly on the device, achieving fully-fledged emulation with incredible speed. It achieves this by leveraging hardware like the Pro Micro NRF52480, which provides the necessary Bluetooth and 2.4 GHz radio capabilities.

The process is incredibly accessible for makers. Once primed in DFU mode, users simply connect the board via USB-C, load the custom Arduino sketch, and their microcontroller instantly becomes an OpenPuck. Want a polished finish? The project even encourages 3D printing a custom case to make the final assembly look truly professional.

To manage the controller’s incredible potential, creators utilize a simple web configurator that employs the WebUSB API. This tool allows users to seamlessly switch between various modes—including Switch Pro, Xbox, DualSense (PS5), and DualShock 4 (PS4). The promise of this setup is high performance, with the project claiming a latency of just 1ms.

The versatility extends across console landscapes. While it can natively emulate a Nintendo Switch controller (even disabling haptics for a Hori Pad feel), it also supports complex PlayStation modes, including a unique DualShock 3 configuration that works with Sixaxis gyro and haptic support on PS3 consoles.

The freedom provided by OpenPuck is truly expansive. But the innovation doesn’t stop there. A bonus sub-project called ReversePuck allows a Steam Deck to act as an external controller, streaming its built-in controls across the room via 2.4 GHz radio directly to the PC. This opens up a new realm of external control possibilities for gamers and creators alike.