What you need
OpenRig needs no custom board: every part is a standard one.
| Part | What to get |
|---|---|
| Computer | A Raspberry Pi 5 (or a Pi 500), or an x86_64 mini PC with UEFI and Intel graphics (Intel N100, Lenovo Tiny…) |
| Audio interface | A USB audio interface that works without a driver (class compliant), or a sound HAT on the Pi |
| Screen | A touchscreen. The UI is made for 1024 × 600 and up; a mouse works too |
| Storage | A micro SD card for the Pi, a USB stick or an SSD for a mini PC; 8 GB or more |
| Power | For a Pi 5, the official 27 W (5 V, 5 A) supply |
| Optional | Up to 8 footswitches and a rotary encoder on the GPIO, MIDI controllers over USB or DIN |
Raspberry Pi 5
Section titled “Raspberry Pi 5”The Pi 5 is the main target. The release images use its PREEMPT_RT kernel, and the neural
engine is tuned for its ARM cores: a full A2 amp capture uses about 12 % of one core at 128
frames.
The Pi 5 gives USB devices 1.6 A only with the official 27 W supply; with any other supply it limits them to 600 mA. A touchscreen and an audio interface both powered from the Pi need the 27 W supply, or they drop out.
Audio interface
Section titled “Audio interface”Any interface that Linux sees without a driver works; the first one found is used. It was
tested with a Focusrite Scarlett 2i2 at 48 kHz and 128 × 2 frames, about 5 ms of buffer each
way. Sound HATs work too: add their overlay in extra.txt (see
pedalboard.txt).
The guitar goes into the first input. The first two outputs are left and right.
Screen
Section titled “Screen”Any HDMI screen works; a touchscreen makes it a pedalboard. Small 10” panels at 1024 × 600 are a good fit. Some of them send wrong display data to the Pi: see Troubleshooting if the picture does not show.
x86_64 mini PC
Section titled “x86_64 mini PC”Any UEFI PC with Intel graphics: the image has no AMD GPU driver yet. It erases the whole disk it is written to. Secure Boot must be off.
Footswitches and encoder
Section titled “Footswitches and encoder”Optional. Momentary footswitches wire between a GPIO pin and ground, with no resistor: the Pi’s internal pull-ups are used. A rotary encoder (A, B and its push button) drives the UI like the arrow keys. See Footswitches and encoder.
Any MIDI controller works too, with nothing to wire: see MIDI.