intertial measurement

3 Articles

A Modern Take On The Etch A Sketch

March 20, 2025 by 6 Comments

The Etch A Sketch is a classic children’s toy resembling a picture frame where artwork can be made by turning two knobs attached to a stylus inside the frame. The stylus scrapes off an aluminum powder, creating the image which can then be erased by turning the frame upside down and shaking it, adding the powder back to the display. It’s completely offline and requires no batteries, but in our modern world those two things seem to be more requirements than when the Etch A Sketch was first produced in the 1960s. Enter the Tilt-A-Sketch, a modern version of the classic toy.

Rather than use aluminum powder for the display, the Tilt A Sketch replaces it with an LED matrix and removes the stylus completely. There are no knobs on this device to control the path of the LED either; a inertial measurement unit is able to sense the direction that the toy is tilted while a microcontroller uses that input to light up a series of LEDs corresponding to the direction of tilt. There are a few buttons on the side of the device as well which allow the colors displayed by the LEDs to change, and similar to the original toy the display can be reset by shaking.

The Tilt-A-Sketch was built by [devitoal] as part of an art display which allows the visitors to create their own art. Housed in a laser-cut wooden enclosure the toy does a faithful job of recreating the original. Perhaps unsurprisingly, the Etch A Sketch is a popular platform for various projects that we’ve seen before including original toys modified with robotics to create the artwork and electronic recreations that use LED displays instead in a way similar to this project.

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Add Scroll Wheels And Buttons To Smartphones With 3D-Printed Widgets Read By Accelerometer

June 17, 2019 by 22 Comments

The first LED digital wristwatches hit the market in the 1970s. They required a button push to turn the display on, prompting one comedian to quip that giving one to a one-armed man would be in poor taste. While the UIs of watches and other wearables have improved since then, smartphones still present some usability challenges. Some of the touch screen gestures needed to operate a phone, like pinching, are nigh impossible when one-handing the phone, and woe unto those with stubby thumbs when trying to take a selfie.

You’d think that the fleet of sensors and the raw computing power on board would afford better ways to control phones. And you’d be right, if the modular mechanical input widgets described in a paper from Columbia University catch on. Dubbed “Vidgets” by [Chang Xiao] et al, the haptic devices are designed to create characteristic acceleration profiles on a phone’s inertial measurement unit (IMU) when actuated. Vidgets take various forms, from push buttons to scroll wheels, each of a similar size and shape and designed to dock into one of eight positions on the back of a 3D-printed phone case. Once trained, the algorithm watches for the acceleration signature caused by actuating a Vidget, and sends commands to the phone to mimic the corresponding gestures. The video below demonstrates a couple of use cases, of which the virtual saxophone is our favorite.

This is really clever stuff, and ventures deep into “Why didn’t I think of that?” territory. Need to get ahead of the curve on IMUs to capitalize on what they can do? You could start with [Al Williams]’ primer on micro-electromechanical systems, or MEMS.

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Adaptive Spoon Helps Those With Parkinson’s

January 9, 2019 by 6 Comments

There are a lot of side effects of living with medical conditions, and not all of them are obvious. For Parkinson’s disease, one of the conditions is a constant hand tremor. This can obviously lead to frustration with anything that involves fine motor skills, but also includes eating, which can be even more troublesome than other day-to-day tasks. There are some products available that help with the tremors, but at such a high price [Rupin] decided to build a tremor-compensating utensil with off the shelf components instead.

The main source of inspiration for this project was the Liftware Steady, but at around $200 this can be out of reach for a lot of people. The core of this assistive spoon has a bill of material that most of us will have lying around already, in order to keep costs down. It’s built around an Arduino and an MPU6050 inertial measurement unit with two generic servo motors. It did take some 3D printing and a lot of math to get the utensil to behave properly, but the code is available on the project site for anyone who wants to take a look.

This project tackles a problem that we see all the time: a cost-effective, open-source solution to a medical issue where the only alternatives are much more expensive. Usually this comes up around prosthetics, but can also help out by making biological compounds like insulin directly for less than a medical company can provide it.

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