Building a Crystal Clear Whiteboard

[Michael Peshkin] teaches mechanical engineering at Northwestern University. He likes to use diagrams to illustrate his point, but he also likes to face his students when doing so. His solution was to develop this clear whiteboard which ends up unlocking a lot more than just some hand-drawn schematics.

It’s a bit hard to see what he’s written on the board in the image above but squint and see if you can figure out what’s wrong with this style of teaching? Everything he’s writing is backwards. That’s not actually a problem in this case as [Michael] uses flip teaching. He records and posts all of his lectures online. Classroom time is then used for question and answer on the lecture subjects. In order to get the text to read the correct way he just bounces the camera off of a mirror.

The board itself is a huge sheet of tempered glass attached to the metal frame using bolts through holes in the pane. This leave the edges free. He added extruded rail to the top and bottom to embed strips of LEDs. They light the inside of the glass, and excite the fluorescent dry erase marker ink making it much more visible. [Michael] didn’t stop with the board, he ¬†also rigged up a lighting system that gives him a lot of options, and uses a monitor for dealing with digital overlays. He can put up a diagram on the computer, watching the monitor to see where his marker is making annotations. All this happens in real-time which means no post production! See a demo of these features after the break.

This could all be done without the glass at all, but that would make it quite a bit more difficult for the person doing the writing.

[Thanks Kevin]

74 thoughts on “Building a Crystal Clear Whiteboard

    1. You appear to be interacting more with the audience when you’re facing them.

      It’s the reason sitcom families all sit on one side of the dinner table.

    2. I’d rather see his face when he talks than stare at his arse-end blocking whatever part of the whiteboard he’s in front of. this is fantastic.

      1. I agree. And so do most people who have ever had to try and take notes off the black or white board while the instructor is talking about the subject at hand and standing in the way.

    3. it’s not that important. but if you want to make it look like a presentation, and it’s not that hard to set up, then why not? I can walk from NY to California, but there is a plane, so i guess I’ll take the plane. Why not?

          1. You have to cut this guy a little slack. He is, after all, a mechanical engineer. On the bright side, the mirror is less computationally intensive than flipping the image digitally. So, if the system is used for a sufficient amount of time, the energy savings will pay for the mirror and then some. Or maybe there were space and optical system constraints that made the extra optical path length desirable.

  1. Very cool he gives away how to replicate it instead of keeping it secret and making everyone think he has the natural ability to write in reverse.

    1. He wouldn’t be fooling anyone. The image is obviously flipped, because the buttons on his shirt appear to be on the wrong side.

      1. But that takes time and effort. It’s much more efficient to complain about topics one knows nothing about. The fact that it makes one appear to be illiterate is irrelevant.

    1. This is where I’d go if I could go back to school and retake the electronics track that I missed out on the first time ’round. When I tried to get into the electronics track we had a USN theoretical physicist teaching E 101 and E 102. He was a genius, but he might as well have been speaking a different language to us noobs. Oh but for a chance to do it all over again with this prof at Northwestern. I hope other schools will take notice of this method and start implementing it… pure amazingness. Wow, just wow!

      1. Method and ability to communicate are two different things. Ultimately it would be nice to get a balanced mixture between good method and good skills. I had a lecturer at uni who would just simply fill up every whiteboard with equations going through the class, it was impossible to follow. But the way he spoke and explained things made him one of the best lecturer’s I’ve had.

  2. Would likely be a cheaper viable alternative to use acrylic glass in place of the tempered glass. Just have to make sure you buff the surface really well to get that crystal clear appearance.

    1. One notes he makes is that the sapphire glass is more resistant to scratching as markers and erasers are run over the surface over time,

    2. I’d be concerned about the acrylic staining over time much like what happens to homemade whiteboards made from Tileboard/melamine. While it’s more of an aesthetic thing with the whiteboard, here it would really effect the quality of the production due to the reliance on the clarity of the glass.

  3. What a strange op amp circuit he’s drawn. Why he needs that transistor input, or puts the feedback on the negative side I’ve really no idea.

    1. so… your input provides negative feedback to the discussion involving an input and negative feedback. Folks, pcf11 is (for all intents and purposes) an op amp.

      that is all.

    2. That’s not a regular transistor. It has no base, so it’s probably a phototransistor, and it’s not referenced to ground but some other voltage.

  4. I watched some of the lectures that Laszlo found, and it seems that the students all got an electronics kit to take home. The heart of the kit is an nscope (http://nscope.org/). Where, for the love of caffeine, can I get one of those units?

    1. Likewise, every tinkerer should own one. Take my money too!:)

      Also those lectures are drugs, just can’t stop watching them.
      Especially knowing the university will sooner or later shut the public off.

      Still I have almost half of the lectures to watch, I think I will be up for all the night:)
      Later guys. Back to “learning”!

    2. It does look pretty nifty, but note that it’s only 400kHz. That’s very slow for most purposes. Of course, when learning AC circuit theory, there’s no need to make things go very fast, and by keeping things slow, you avoid a lot of confusing issues around parasitics, you don’t need expensive scope probes, and you can build your circuits on those breadboards. Looks like a fantastic tool for its purpose, and a fun thing to play with, but something that would be easily outgrown. I bet it could be a profitable commercial product, but who knows what legal issues might make it difficult for the public university to sell the design to non-students.

    3. It looks like, from browsing the sites involved, that the nScope is possibly one of the projects that the students are required to complete. If they are all required to complete this circuit, then they all have the same standardized hardware to use with the course.

  5. I was impressed with the concept, but then when I saw the actual video… WOW!

    I’m curious about the drilling though. I was under the impression that tempered glass couldn’t be drilled.

    1. I think it involves unicorns or narwahls. it’s all done in a special factory with no windows. none of us are quite sure how it happens.

        1. To drill this non-tempered glass (see comment below about how I was wrong about its being tempered), I used a diamond bit from Harbor Freight in a Dremel tool while spraying water on the glass for cooling.

      1. Really? how?
        Tempering glass increases the surface tension, as soon as you breach the surface it shatters like a soap bubble (or a prince rupert’s drop).

        1. I was mistaken; the glass in question wasn’t tempered. The glass was from a window pane. I knew it wasn’t tempered at the time I was drilling it several years ago, but since then I got mixed up about the federal law in the U.S. requiring tempered glass in doors. I was thinking it applied to windows too, but it doesn’t.

          1. Windows immediately adjacent to doors in buildings with public access (such as restaurants) must be tempered glass.

  6. I don’t know why lecturers insist on repeatedly writing things out instead of honing a presentation and talking through it. Just makes it hard to read, no consistent notes to follow, points missed, etc.

    1. Because when you hone one presentation, you get slack and you don’t update it regularly, so your lecture becomes more and more useless with time… See it as the inverse of Moore’s law. I do agree that presentations is often more useful, but not all lecturers have time to make new presentations each time. Also, some people feel using a presentation is more like preaching or just repeating, while when they write, they feel one with the work so they give you their insight. If they do however write on the board from a book or scrap paper, then they are just plain lazy.

    2. The act or writing can be followed by the reader. It helps the learning process to watch the hand-drawn words.

      Having him “speak” the words while writing triggers more modes in the human brain. Our mirror neurons trick us into feeling the writing process (touch), while reading the words (sight) and hearing the words (hear). By triggering several modes simultaneously, the viewer is more likely to understand the topic.

      (When you explain things, some people will say “I see”, some will say “I hear you”, and some will say “that feels right”. This is a clue to the mental mode they work from, and you can tun your explanation to better trigger that mode.)

      Just showing the text suddenly robs the viewer of some of those perceptive clues.

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