Creator DuctTapeMechanic loves sports and electronics, so for a recent project he decided to combine his two passions by hacking a speed bag to keep track of his punches.

As shown in the video below, the first step was to get it physically set up, modding an old metal bed frame into a support structure. He also added a recessed NPN capacitive sensor to pick up when the bag hits the back of the platform.

The sensor sends “hit” signals to an Arduino Uno via a PC817 optocoupler. The board then counts punches and displays the number of hits on an LCD screen mounted just above eye level.

Whether it’s competing with friends or simply improving your boxing skills, DuctTapeMechanic’s system looks like a fun one to build yourself!