Wristwatch Measures Your Perception Of Time; Also Tells Time

This wristwatch is hiding a lot of features in its hardware and its software. It’s called the TicTocTrac and it’s a Senior project for a pair of students at Cornell University. Judging from the sheer volume and quality of the project documentation we wonder if someone has a science writing career ahead of them? Be we digress… It’s a clock and we love it!

First off, this does more than just tell the time. In fact, that’s almost an ancillary function in this case. The wristwatch is more of a metering device to record your own time-based behaviors. Find yourself checking your watch frequently as the lunch break approaches? This watch records that activity and you can later graph the data. This allows you to analyze how you percieve the passage of time. The more often you check the time, the slower you feel time progressing. The documentation does a much better job of describing this than we have time for, so check it out.

On the hardware side of things we’re quite impressed. The housing is 3D printed. It hides two half-circle PCBs below the full-circle PCB face plate. The half-boards leave space for a tiny rechargeable battery, and host a vibrating motor and RTC chip. Instead of using buttons, there’s a piezo sensor which detects when you tap on the top of the watch.

15 thoughts on “Wristwatch Measures Your Perception Of Time; Also Tells Time

      1. First of all:

        Second: You must not have much experience with PCB Creation. Traces mean everything. Besides the look and actual current flow its a professional thing…

        Why do most companies develop PCBs with no 90 degree angles? Why do most companies dont use round traces? There are a ton of reasons. If the trace didnt matter pages like this wouldnt have to exist:

      2. Of course width is a factor, but except for aesthetic reasons the angle of a trace does not matter, and as long as you keep a bit above the minimum width the angle of an elbow doesn’t matter either. (the inside of a very sharp corner can collect and concentrate etchant during the etching process and etch away too much of the trace)

        A large reason for 45 degree angles is that routing this way is very fast, you do not have to judge every corner individually.

        By the way, I do design boards both for hobby and professionally.

  1. Looking at the write-up, it appears that it’s actually one half-circle board beneath the clock-face board (it’s pictured front and back). Great project, regardless.

  2. Not quite sure how practical this would be but it’s certainly an interesting build.

    On a side note, I’ve always wondered how one lays out a PCB with so many LEDs in a non-rectangular layout. It seems that it would take a lot of patience and time to layout evenly.

  3. Brian, one of the TicTocTrac creators, here.

    Our PCB design is sloppy, but for good reason. First, I want to make clear that we were actually very careful to make sure it would work and hopefully we will put together a video soon. Our project is very low current and low power, so the thin traces and occasional sharp turns are acceptable. We also paid close attention to important sections, such as making sure the oscillator traces were short and about the same length. The main reason for the sloppiness, was the fact that final projects are done over the course of a little over a month. We had to design this PCB very rapidly to allow for the time it takes to have it manufactured. Also, the fact that we are from Cornell is irrelevant. Unfortunately, much to my dismay, Cornell doesn’t currently teach PCB design at the undergraduate level. For both of those reasons, very few groups in 4760 design a PCB. Hope I’m not feeding the trolls here, but wanted to explain.

    Also, it is indeed only one half-circle board.

  4. Ah i see. Thanks for explaining that :) Dont mistake the sloppy comment for bad work :) Its a awesome watch and i didnt know there was a time frame thing. As i said i skimmed over the page so i assumed (this time i made a ass of myself) that it was a longer time frame granted to students.

    But all in all this was a great job done and i applaud you and the other person.

    Sorry if my comment sounded like im a a-hole… sometimes i just say what i say without knowing the whole story… call it laziness :)

  5. Brian,

    Wonderful project and totally exceptionable work for a prototype, given the time frame.

    You are right about the Cornell thing, that is completely irrelevant.


  6. I love the look of the watch, if it was slimmer I would probably wear it day to day.

    I must ask, why use a hardware RTC when you have a perfectly good low-power microcontroller?

    I see this all the time on clock projects :-)

  7. A good build. One thing that bothers me is the goofy sections Cornell Engineering students must include, ” Ethical and Legal” considerations.
    Are Cornell guys that bad ? Really .
    This type of brain washing must be questioned and or stopped. In my 30 plus years as an Electrical Engineer in Aerospace , I never had to include rubbish like that in any report.
    My suggestion to young Engineers-
    Question everything !

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