Steam Controller owners who want ordinary gamepad compatibility without keeping Steam open now have a DIY route. A hobbyist developer using the name Safijari has published OpenPuck, open-source firmware that turns a small wireless microcontroller board into a replacement puck for Valve’s new Steam Controller.
The practical problem is boring but real: Valve’s new controller does not offer native XInput support, according to Tom’s Hardware. Steam can translate the controller through Steam Input while it is running, but that ties the device’s broader compatibility to a PC-side software layer. OpenPuck moves that translation onto the puck hardware.
How OpenPuck works
Safijari’s firmware reads the raw data coming from the Steam Controller and converts it on the microcontroller before sending it onward as another controller type. The project says this allows real-time emulation of several common pads without Steam Input handling the mapping in the background.
The developer used a Pro Micro NRF52840 board, which has the Bluetooth and 2.4 GHz radios needed for the job. The project notes that other compatible boards may work. Setup, as described by the project, involves putting the board into DFU mode, connecting it to a computer over USB-C, and dropping the Arduino sketch onto it. Safijari has also posted a 3D-printable enclosure for builders who want the result to look less like a naked development board lost a bar fight.
Configuration happens through a web page that uses the WebUSB API. From there, users can select the emulation mode and manage the puck. The project description claims about 1 millisecond of latency, a number that should be treated as the developer’s claim unless independently tested.
Supported controller modes
OpenPuck includes modes for Switch Pro, Xbox, DualSense for PlayStation 5, DualShock 4 for PlayStation 4, DualShock 3, and the default Steam Controller behavior, according to the project documentation.
- Switch Pro mode works natively on a Nintendo Switch and supports gyro and haptics, according to Safijari.
- A Hori Pad emulation option is available for Switch use, but it disables gyro and haptics.
- The DualSense and DualShock 4 modes are listed as PC-only.
- The DualShock 3 mode can work natively on a PlayStation 3 and includes Sixaxis-style gyro and haptics support, according to the project.
Some modes can be changed from the controller by holding all four rear buttons and pressing A, B, X, or Y. The PlayStation modes require the web configurator instead.
A Steam Deck side project
Safijari also lists a related experiment called ReversePuck. It uses a second NRF52840 Pro Micro connected to a Steam Deck, allowing the Deck’s built-in controls to be streamed over 2.4 GHz to an OpenPuck-equipped PC.
The project says ReversePuck supports the Steam Controller’s features except grip input. In practice, that gives a Steam Deck a second job as a wireless external controller for a PC, provided the user is willing to flash more hardware and accept the rough edges that come with hobby firmware.
This story draws on original reporting from Tom's Hardware.
