OpenPipes hardware covers everything between the organ console and the computer: MIDI controller boards, stop modules, expression pedals, pedalboard sensors, and peripheral controls. Two generations are available — the current PIPE 2C platform (I2C/USB, solderless) and the legacy Arduino-based system documented in the OpenPipes Book.
OpenPipes hardware is organized into two platform generations:
Current Platform - PIPE 2C
I2C/USB based modules that chain together with no soldering required. Six types: stop tabs, pistons, draw knobs, expression pedals, pedalboard sensors, and analog faders. Compatible with the Qwiic and STEMMA QT ecosystems. Explore Pipe2C →
Legacy Platform
The original OpenPipes hardware system, fully documented in OpenPipes: The Book. Arduino-based MIDI controller with multiplexed extension boards, NeoPixel LED feedback, and a complete range of peripheral modules (rocker buttons, pistons, expression pedals, drawknobs, sliders, and keyboard encoders).
Hardware Controllers and Parts
PIPE 2C is the current OpenPipes hardware platform. It uses I2C and USB with standardized 4-wire Qwiic/STEMMA QT connectors throughout — no soldering, no custom wiring harnesses. Modules daisy-chain and can be mixed with any compatible off-the-shelf I2C hardware.
Why I2C
Most VPO electronics available today are either hard to source, require custom wiring, or need soldering skills most builders don’t have. PIPE 2C is built on I2C - an open standard used by Qwiic (SparkFun), STEMMA QT (Adafruit), and M5Stack - which means off-the-shelf parts and a standardized 4-wire connector throughout.
Legacy Hardware
The original OpenPipes hardware platform, based on Arduino and the 74HC4067 multiplexer IC. A central MIDI Controller Board connects to daisy-chained extension boards and peripheral modules through ribbon cables. Fully documented in OpenPipes: The Book.