I found this video on my hard drive from a couple years back, when I built a ‘tacit glove’ for a friend. No audio (too much static), but I decided to put it online to showcase the glove in action, albeit silently.

For those not aware, a Tacit Glove was a design from Steve Hoefer of Grathio Labs. It used two sonar range sensors in front, slightly angled, and two servos behind. The idea was that as the hand drew closer or farther from something, the levers of the servos would go up or down, pressing against the back of the hand and giving useful feedback.

Unfortunately, the audio was horrible – just hissing – but if it was good, you’d hear the servos go up and down as they translate distance to up/down pressure (close is down, up is far). In the video, the glove is pointing down a hallway, so some of the readings are because the angled sensors are reflecting off the hallway walls.

My version differed from the original in that I didn’t have the plastics he had access to – instead, I put everything into a plastic corrugated ‘case’ and placed that directly on the neoprene glove with Velcro strips instead of putting a cover over it.

Working with it, I found some design issues:

• Pointing it is awkward, with the angle a bit hard to get used to as you move it.
• The servos are near-constantly moving, and cheap ones (like the ones I used) are very noisy.
• While the original Grathio Glove was quite pretty and svelte, I found fitting the parts into the box made for a very large and bulky device. While it could be made a bit smaller, ultimately, the two sensors do take up quite a bit of space above the knuckles.
• Likewise, the angled sensors gave somewhat confusing readings. Since they were angled to the left and right slightly, they actually responded to the sides as well as the front. Notice the video pointing down a hallway – the walls occasionally triggered a sensor reflection.
• The parts could have been cheaper. I’m not a fan of the Ping))) sensor, since it seems about the same capability as the HC-SR04 found on eBay (and many times the price!) If I was to spend $30 for a sensor, I’d use the all-in-one Maxbotix devices (which I did later on in my Sonareye ‘flashlight’)
• For long term, the neoprene is quite warm. Comfortable, though.

All in all, it was a good experiment to build it – trying it out got me used to working with the Arduino Pro Mini, led me to develop different versions, and eventually my simpler Sonar ‘Eye’.