Talking Digital Calipers Make Engineering More Accessible


The team over at NerdKits recently put together a device aimed to help make the process of measuring things more accessible to those with disabilities. [Terry Garrett] is a Mechanical Engineering student, and as anyone who is in the field knows, it’s a discipline which requires taking tons of measurements. Since [Terry] cannot see he was often asking classmates to assist in measuring items during labs, but when he got a job at a nearby design studio, he knew he would have to find a way to take those measurements on his own.

Enter NerdKits.

[Humberto] wrote in to share how he and his team built a set of talking digital calipers to assist [Terry] in his daily tasks. They based the design off a previous project they worked on, getting digital readout data from a set of calipers. The DRO information is fed into an ATmega382p, which pieces together pre-recorded sound bites to announce the size of the object being measured.

As you can see in the video below, the system looks to work very well, and [Terry] is quite pleased with his new talking tool. We love seeing these sorts of hacks, because they truly make a difference in people’s lives – excellent job!


14 thoughts on “Talking Digital Calipers Make Engineering More Accessible

  1. Mixed feelings on this one. While I think it is cool to make a talking calipers. I have to question the safety of a blind person on a milling machine like that. My wife works with disabled people and one of the big challenges is finding jobs that fit the capabilities. Safety is often a concern. Having said that often the greater disability is the mind set, not the actual physical or learning disability. I applaud Terry for making the most of him self.

  2. @tjb

    I personally know one machinist that is blind. He makes the sighted look blind at how precise and incredible his work is. I also know a blind woodworker that makes pieces so elaborate it amazes many people that his work is so perfect.

    1. That is very cool And backs up my thoughts that disability is more of a state of mind in many cases. I am more curious how he can do it safely. Should he do it is for him do decide. I am not one to tell some one they can’t do some thing.

      1. This is a really cool idea! You shouldn’t think of this as “because it exists it will put visually impaired people in dangerous situations”, but rather “this has the potential to open up a new world of understanding to the visually impaired that touch alone cannot describe”

        Great job Nerd Kits!

  3. If someone is visualy impared, use a more accurate caliper, not a $20 pair. And use the proper cable, and decoder, just my 2cents, other than that, I think this is a neat hack, and will use some of it for my cheapo calipers, but not for anything accurate

    1. $20 calipers are accurate enough for most people, and way better than not having a pair of digital calipers.

      I can remember before having a pair of digital calipers, I used to try and look at parts next to a 0.01″ graded metal ruler through a 10x loupe. Boy did that suck, was inefficient and not very accurate.

      Now I only use the cheap stuff from Harbor Freight, and it’s plenty accurate for doing engineering work down to 0.001″.

    2. Believe it or not, my cheap lidl chinese caliper is in fact on par with my mitutoyo one.
      And this was tested from 1 to 100mm with precision grade 0 gage blocks.

      In fact the mitutoyo was always 0.05mm off if not handled correctly (ie putting to much pressure on the jaws). But in the end it is more smooth to use and eat less battery.

      This was not the case with palmers. Mitutoyo/Roch mechanicals ones where good to the micron, where chinese where 0.005 mm off (5 microns). Not so bad for 0.01mm resolution palmers.

  4. I enjoyed this article, and have found the talking calipers to be the best tool I have ever used in my work at mind studios.

    as for the milling. I don’t manually run the machine, the cnc excepts g-code (programming code) and that is how I tell the machine to cut my parts.

  5. Just a thing to remember if you are going to take this interface any further: These calipers are POSITIVE ground. That is, the positive side of the button cell battery is connected to the metal parts. Just a thing to consider if you are going to interface to other electronics that may share a common ground with your equipment, a mill for example.

  6. What a great project, better value for money than commercial options. I note the usual prejudice about blind machinists which always seems to arise. My son has been using both manual and CNC lathes and mills for years without losing any fingers and he is totally blind.

  7. I needed a caliper to help me with nonvisual drawing and 3d modeling — I’m Blind and teach accessible CAD at the New York Public Library. I discovered that for $100 or so on eBay you can buy an iGaging Smart Origin Cal, which connects to your smartphone or computer as a keyboard. This approach has notable advantages:
    -Output comes to you through whatever speech engine or Braille display you already use
    -The device itself is silent and you can use headphones with your destination device (important in a library)
    No unwieldy wires
    -Long-lasting charge with a standard watch battery (it comes with one extra)
    -Measures inside, outside and depth in both inches and milimeters
    -Track measurements in any doc or spreadsheet
    -LCD screen so sighted collaborators can borrow it
    This is my first digital caliper so I’m sure there are limitations and drawbacks I’ll find out about later but for now I’m super excited to own something so well-made that just happens to be nonvisually accessible.

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