Lego Sherlock Holmes figure focuses a light beam on a Lego criminal with a small magnifying glass.

LEGO Regulated Air Compressor

setup of regulated air compressor.

LEGO air compressors are typically built using a Technic motor, but I decided to use an EV3 motor. The EV3 motor in combination with computer control allows regulation of the air compressor to keep an air tank pumped up to set point pressure. Most practical air compressors in garages, car repair shops, and industry work this way to keep the pneumatic pressure supply ready to go. The only thing special needed to build a LEGO version of a regulated air compressor is a means to measure air pressure. Fortunately, such a sensor is available from Dexter Industries ( in their dPressure device. The BrickPi3, also from Dexter Industries and used throughout my previous blog posts, comes with interface code to work with the sensor. I used the interface code in a Python program to keep a pneumatic pump activated until the desired set point pressure is reached. If the pressure goes below the set point, the pump is activated again. As in the photo above, a display is added to see the current pressure in the air tank and the set point. Everything working is seen in the video below.