This DIY trainer is like a Whack-a-Mole for boxers

Back in the 1985 classic Rocky IV, Balboa’s rival Ivan Drago was shown utilizing a futuristic electronic punch meter in his quest for triumph. Inspired by the flick, a group of Cornell students recently designed their own electronic boxing trainer system for beginners and well-seasoned athletes alike. The device is capable of teaching both basic and advanced combinations, while also providing users with a gauge of timing and accuracy.


“While we desired to have ‘built-in’ sequences to train the user, we also desired to allow the user to self-program and store their own practice combination sequences. We attempted to do this without exceeding a budget of $100,” the team writes.

The project is comprised of five square pads organized in the shape of a human head and upper body, with each square surrounded by bright LED ribbons that emit light based on a pre-conifgured pattern. Think of the system as a life-size Simon or Whack-A-Mole: When a pad lights up, the trainee must hit it. If the user fails to strike the pad within a set deadline, the next punch in the sequence proceeds. The game, which is controlled by an ATmega1284P, keeps tabs of the user’s activity in terms of reaction, accuracy and other relevant statistics.

In an effort to keep costs at a minimum, the students created their own force sensors consisting of two square pieces of fine aluminum windscreen with foam structures placed in between. One of the foam pieces was made from conducting ESD foam, while the other was a piece of half-inch thick insulating foam rubber with quarter-inch slits cut approximately half an inch apart, for approximately 12 slits per sensor.


“In each of the screen pieces, we thread (copper) wire through the (aluminum) screen’s holes in a ‘Z’ pattern and bond the metals together with conducting glue. The jailbar foam is then hot-glued to the ESD foam, and then the composite foam is sandwiched via hot glue between two of the wire-threaded screens. The screens are then covered on their exposed sides with cardboard that has been rolled with a wine bottle to reduce its brittleness (by popping any trapped air pockets). We used four 10” by 10” sensors to create the ‘body’ of a figure, and a 9” by 9” sensor for the head.”

The sensors are then mounted against a wall, or in the Cornell project’s case, a back of a metal exterior door. When a user punches a sensor, it compresses and as a result, causes the resistance between the two pieces of aluminum screen to change. This greater the change in resistance, the more powerful the hit.

Meanwhile, feedback to the user and the programming interface is done by serial communication. The team interfaced with a PC using a USB-RS232 cable and PuTTY.  The code for the system can be divided into three distinct categories: initialization, user input via PuTTY (or other serial terminal) and game play.

Interested in learning more about the project as well as the team’s outcome? You can read the entire log of their build here, or watch a demo of the boxing trainer below.


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