This repository contains code for the electronic pressure regulator described in our All-in-one microfluidics control system article. Please refer to the article for instructions on how to build and program these.
Details are also available on Hackaday.io.
Two proportional solenoid valves are used: one on the inlet to let pressurized air in (from a pump, gas tank, etc), thus raising the pressure. A second proportional solenoid valve can be opened to vent excess air and lower the pressure. A sensor on the outlet allows the microcontroller to regulate pressure rapidly and precisely using a PID loop. That's it!
Set points and current pressure values can be transmitted in 3 ways: over USB, i2c or analog. This way, the regulator can be included in all sorts of projects, whether as a benchtop tool or on a robot of some sort.