Whiteboard Clock | Hacker News Reader

Whiteboard Clock

docs.google.com

784 pointsunbeli82 comments

I missed the youtube video the first time around: https://www.youtube.com/watch?v=4QgeQAiSmM8

It's hilarious how while it's writing it looks like two small arms cupping the marker. Slap on a smiley-face sticker and you're ready to go to market.

It would be fun to see it write in your own handwriting. Also, I was thinking something like this [0]! :)

[0]: https://wessonblog.files.wordpress.com/2011/05/hitchhikers.j...

It's funny how even though it's a computer font converted to straight lines, it winds up looking very much like a real person's handwriting.

>> It's hilarious how while it's writing it looks like two small arms cupping the marker.

I was thinking the same thing. I envisioned a Muppet head and arms would do the trick.

This reminds me of a "plotclock" that I built almost a year ago.

http://www.thingiverse.com/thing:248009

The writing on this one is much nicer! Add selective erase so only one character is (usually) ever erased and you've got yourself a very neat novelty clock.

I feel really bad for the little guy. It looks like he's incessantly unsatisfied with his work so he has to erase everything.

Just out of curiosity how is the ink usage, could it run for longer then a without replacing the pen or refiling the ink?

EDIT: Just saw the super interesting comment bellow linking to a reddit thread where it calculates the theoretical values of ink usage.

Please someone sell these!

If you own a 3D printer, there is a model up on http://www.thingiverse.com/thing:248009.

No! Go build one. So much more satisfying than buying.

A kit would be nice for those without the necessary expertise or access to a 3D printer.

Just curious, how much you'd pay for the 3d printed parts?

With a kit containing all the required components, along with instructions perhaps something like $30, but I'm not sure the cost of such things.

You don't need a 3d printer. Access to a laser cutter will suffice.

Not sure if you meant this as a joke (a laser cutter is probably harder to come by than a 3d printer). But back in my day for things like this we simply used a jig saw to cut out parts from wood or plastic. Anything more complex would need several pieces cut out and glued together.

> access to a 3D printer.

Time to meet your local hackerspace perhaps?

Or library! Some libraries have them.

libraries are thinkerspaces.

http://hackerspaces.org/

And if you don't have a 3D printer you could perhaps use on nearby you via 3D Hubs, https://www.3dhubs.com/

We made on of these at my school - kid's thought it was incredible. https://www.youtube.com/watch?v=ClEEPBDfA0Y

We want to make ones that sit vertically on our actual whiteboards and run off more permanent power-supplies.

So the inevitable next step is a full scale (powerpoint) presentation to vector stroke path exporter?

Quite lovely to see in action. Apparently I am so primitive that I still think digital watches are a pretty neat idea.

My take on this concept from undergrad [1]. It's a bit less refined but a lot more powerful, using an industrial robot.

[1] https://www.youtube.com/watch?v=HoAqbQsY-sY

Here's an analysis of how often you would have to change the marker on a similar clock: https://pay.reddit.com/r/theydidthemath/comments/2vky0v/requ...

The next step: Enhance design so clock can change its own marker.

Or feed the marker's liquid reservoir from a larger tank.

Or use a chalkboard.

Or some gears and a battery.

Chalk would still run out and need to be replaced. Some kind of sand drawing would be more of an infinite "ink".

Hilariously, a good way to do this with infinite "ink" would be to draw the letters on a touch screen with a stylus.

Or, just use one of the children's magnetic drawing board?

http://en.wikipedia.org/wiki/Magna_Doodle

I'm fascinated by this project, but I also find it kind of unsettling. I think the "arms" make it fall into the Uncanny Valley for me.

Are these arms too human-like for you?

https://www.youtube.com/watch?v=JcniyQYFU6M

How do you go about setting up a custom device file like that (/dev/whiteboard)? Is it just writing a device driver?

I think you could just hook up an old pen plotter to your whiteboard.

https://www.youtube.com/watch?v=6_pwzqPk6Gg

[EDIT] whatever it has been done before:

https://www.youtube.com/results?search_query=pen+plotter+whi...

But this of mechanic is certainly unique and adds a lot of clumsy robot charm.

Wonder how easily you could store human inputs with a kind of (reverse) Pantograph type device for reproduction.

http://en.wikipedia.org/wiki/Pantograph

The author says the device is a USB modem. So, under Linux, the author could have simply written a udev rule to use the name "whiteboard" for that particular USB modem's device file.

And even under plain-Jane Unix, you can name a device file whatever you want.

Indeed. It's just a udev rule with: SYMLINK+="whiteboard

I'm also wondering why not skip all the protocols and put a clock on the robot? Either way, cool project!

Let's say someone wanted to learn how to do this. Not just follow a step by step guide, but actually learn how to do this. Where would you find a good resource?

This of course depends on what you know already (CS or EE background?), but the easiest way would be to use an arduino. You'd need to have some electronics knowledge (basic circuitry, servo motors) and be able to do some embedded programming (PWM, ADC/DAC, interrupts/timers)

This was a nice overview. Thanks.

You would need to control a pair of servos. Arduino is the easy way. Some trigonometry to convert x-y positions to the two arm angles. The connectors to the pen are linkages.

I am currently building a whiteboard plotter myself, though a much larger scale.

Feel free to send me questions and I can send you pointers on where to research next.

There are three parts to learn -- the electronics (handled by an Arduino and a few servos), the mechanics (for this design, it's not too complicated -- you could make do with popsicle sticks and some screws if you had to), and the software. The tricky bit with the software is the math. The arms, when free to spin around their centers, can be considered circles. You'd want to learn the geometry of circles and, specifically, how to find the intersection of two circles. The joints on the arms are where the circles meet.

I'm working a new version of my mobile testing robot that looks very similar to this clock. Haven't posted the code, yet, but I did have to go back and re-learn some trig and circle geometry to make the simulator. http://youtu.be/qRzrm4zx82g

Hey Jason, good to see you again.

A good starting point might be to use Lego + Mindstorm (or Lego + Arduino). You get to use various off the shelf mechanical parts and you get to re-use the Lego parts in your next project.

Yup, that's a fine suggestion, too. I used to do all my prototyping with Lego Technic pieces... Years later, when I needed parts that Lego didn't make (like for connecting servos or Arduino), I used Lego dimensions to create my own 3D printable (but Lego compatible) parts.

Thanks, I'll keep you in mind as I get started.

Why wouldn't you go for a Lego Mindstorms kit?

You could probably build a similar thing almost out of the box (BYO marker and whiteboard) and you can replace the various parts with your own bits as you get more advanced.

I suppose if you knew what you were doing going an Arduino is a cheaper option though.

I love the way it writes, it has so much personality.

Yet if you watch the video, each time the "natural" looking numbers are almost identical.

I liked the erasing style. Bit clumsy like a toddler.

I can't help to feel this is a step near Harry Potter's Hogwarts via technology devices

How did you make this google doc work like this? Pretty cool usage of the medium.

It seems like it's just a "published" google doc.

I've made one that describes the process, if you are interested: http://goo.gl/Ykq88g

Kickstart this and let me give you my money.

Using a home presence API (like Nest's), this thing could also abstain from updating the time until you were home or in the same room as it. That could dramatically reduce wear and tear.

Just hook up a human PIR to that thing. Only $4-5.

by the time you're physically close to it, it's too late.

A cool next step (especially for classrooms) would be giving the robot "eyes" and letting it get the time from a physical clock in the room via image recognition.

Could eventually be extended to scetch outlines of objects/people :D

"But I had to add some tape, as it wasn't strong enough to keep itself in place properly"

I hope it was duct tape, otherwise it may not last for too long. Funny project, done in a cool way, and a great hack.

Cool! Although I wonder why not erase from the right and save ink?

Somehow reminds me of Hektor, the grafitti robot: http://juerglehni.com/works/hektor/

It's a bit disappointing that they went to the trouble of building a radio into it and didn't just connect it to the NIST atomic clock radio time signal WWVB.

Sorry for asking this stupid question, but what program is that waveform screenshot from? I've been looking for a GTKWave alternative for some time now …

Looks like an old version of Saleae Logic, maybe?

Awesome, I think this might be just what I was looking for – Thank you!

Yeah, I have one, it's fantastic, highly recommended.

The cap isn't on the pen properly, so it'll dry out. Share prices of marker pen manufacturers are going to soar! :)

This is brilliant - how would you go about learning to build this? Are there any good resources online?

Hmm, I might have enough Legos left to make an implementation of the mechanics with them?

How about using and Etch a Sketch then it would not need to be supplied with ink.

I feel like I've seen this video many years ago...

It actually writes like an actual human! Love it.

I just bought a new whiteboard, This looks like fun.

http://i.imgur.com/0AtSlry.jpg

Duh. Why this is cool: White-board clocks are among the oldest things on "the Internet".

Got a link to another one?

https://news.ycombinator.com/newswelcome.html "The worst thing to post or upvote is something that's intensely but shallowly interesting: gossip about famous people, funny or cute pictures or videos, partisan political articles, etc. If you let that sort of thing onto a news site, it will push aside the deeply interesting stuff, which tends to be quieter."

While it has cute aspects it's also a very cheap, elegant solution to automation on a whiteboard which most people probably think of as out of reach.

It's somebody's project, not a cat video.

It's a very cool/fun project and definitely not a cat video. I do believe that it's relatively "shallowly interesting" and I haven't read any comments yet that would indicate to me otherwise. I take the 550+ up-votes it's gotten as a sign that the value (for me at least) of the hacker news filter is slowly degrading.

Sincere answer: I look and this and think: how did they do that? Do I know how to do that? Could I do parts of it "better"? Knowing this is possible, are there cooler things I could do with it?

If you're willing to think about it for a little while, there's much beyond shallow interest.

Snarky answer: Would you consider toy railroads relevant to hackers? http://en.wikipedia.org/wiki/Tech_Model_Railroad_Club

Someone hacked together something and is sharing it. It's exactly what HACKER News is about. Heaven forbid someone do something relevant to the site and share it. Lets get some more X rewritten in y lines of JavaScript posts instead.

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