Repurpose a Classroom Clicker for Great Justice

If you’ve been in a university class of a certain size, with a professor who wants to get live feedback from the students, you’ve probably been forced to buy a Turning Point “clicker”. Aside from the ridiculousness of making students pay for their professor’s instructional aides (do the make you pay extra for the chalk too?!?!) these clickers are a gauntlet thrown down to any right-minded hacker because they supposedly contain secrets.

[Nick] had one of these gadgets, and hopped right up on the shoulders of giants to turn it into a remote control that interfaces with his computer and drives a synthesizer, so he can work through the chord changes by clicking. His two references, to [Travis Goodspeed]’s nRF promiscuity hack and to [Taylor Killian]’s Arduino library for the clickers are a testament to why we need both reverse engineers doing the hard work and people who’ll wrap up the hard work in an easy-to-use library.

That’s it, really. [Nick] hooked up an Arduino to an nRF24, sent the decoded output from the clicker to his computer, and wrote a Python routine that would play whatever music he wanted over MIDI to a baseline synthesizer. The whole shooting match is available on GitHub. If you have one of these clickers collecting dust somewhere, pull it out and do something with it.

40 thoughts on “Repurpose a Classroom Clicker for Great Justice

  1. never seen these before but they sound pretty stupid. wouldn’t you just sell it to a first year student when you leave? or give it away, put the company out of business.
    The closest thing I have seen to feedback was when someone noticed the laptop doing the slideshow was advertising Bluetooth and we could end the slideshow by trying to pair as the laptop would ask for the 4 digit code. great fun.
    A friend sent me some python yesterday as it happens, and it refused to do anything claiming that there was a mismatch between tabs and spaces. I tried tabularising it and detabularising it but it still complained. I edited a few lines before giving up. I don’t understand how python can claim to be a good scripting language to throw something together and hack with when it can’t even deal with whitespace without throwing a hissy fit. the program was a few hundred lines I just told the guy never to contact me ever again.

    1. Sounds like he needs to use a proper text editor. One that understands the concepts of tabs and spaces.

      Python coding style guidelines forbid spaces for the exact reason you’re having problems: it is indentation sensitive, and while it can deal with tabs, and with spaces, a mix confuses things.

        1. Python is the #1 most popular scripted programming language for very good reason.

          Personally I love the indentation requirement. After working years and years and years with crappy programmers who can’t figure out indentation, it’s a massive breath of fresh air.

          The Zen of Python
          ————————
          Beautiful is better than ugly.
          Explicit is better than implicit.
          Simple is better than complex.
          Complex is better than complicated.
          Flat is better than nested.
          Sparse is better than dense.
          Readability counts.
          Special cases aren’t special enough to break the rules.
          Although practicality beats purity.
          Errors should never pass silently.
          Unless explicitly silenced.
          In the face of ambiguity, refuse the temptation to guess.
          There should be one– and preferably only one –obvious way to do it.
          Although that way may not be obvious at first unless you’re Dutch.
          Now is better than never.
          Although never is often better than *right* now.
          If the implementation is hard to explain, it’s a bad idea.
          If the implementation is easy to explain, it may be a good idea.
          Namespaces are one honking great idea — let’s do more of those!

  2. A friend was complaining about these a few years back, after one of his classes required the purchase of one.

    He, as a comp sci student, and veteran of the field already, proceeded to figure out that they had no particular security other than the hardware identification number that each broadcast when you pressed a button. A little bit of brain storming later resulted in plans for a mitm spoofing attack for a classroom, since the grading system only accepted the first answer from each clicker.

    Discretion kept it from being fielded, but he was a bit indignant about it, both being required to buy one, and that they were so poorly executed.

    1. “Discretion kept it from being fielded”

      I would not have had that same amount of discretion. :) Although I wouldn’t have done it in a final exam.

      That’s what we call a “teachable moment” in the biz. There’s no rule against the students teaching the profs.

      1. Well, he did show how insecure one of the CompSci online submission system was, and then demonstrated the issues for the professor, but who knows whether the Prof was even able to affect it, as it may have been controlled by the university IT staff (who should have known better…)

  3. I agree that education shouldn’t force you to spend money, especially to a proprietary hardware developer, you *do* often have to pay for books, so I’m not sure why everyone complains about this one so much.

    1. Like the article mentioned, in this case you’re paying for the professor’s teaching aids. Books make more sense for the student to buy since it’s something they will use to help themselves.

      That being said, I don’t know of any student that hasn’t complained about buying textbooks.

      1. Not only are you paying for the teaching aid, you’re most likely part of his research. The clicker results turn up in all kinds of higher ed studies – most of them awful – and are a way of fleshing out one’s publication list.

        As a prof who doesn’t use them, I’d just love to see these spoofed.

        1. Clicker activities can (if done correctly) aid education. I’m not really clear on this distinction between teaching aids and educational aids. I’d never heard of that distinction before this article.

          I also teach college courses without clickers. But I’ve also thought a lot about them and their potential benefits, and I feel a lot less strongly opposed to them than I did before. There is plenty of garbage education research out there, just as in any field, but there’s also some careful thoughtful work done on this topic. As with most things, the most opinionated people usually haven’t thought more than a few minutes about it.

          1. > Clicker activities can (if done correctly) aid education.

            Yeh. If they’re bought a lot they do help in the clicker vendor’s CEO’s children’s education.

            For me, there’s a big DIEBOLD written over all of that. In orange, flashing letters. Insecure, borderline superfluous, but the manufacturer doesn’t give a hoot, because the one taking the decision to buy isn’t the one paying isn’t the one having to suffer/use it.

            (Sorry, couldn’t resist — a bit grumpy today :)

        2. As a prof who would know about them, you would know that collecting data from students to use in any study requires consent via Institutional Review Board (IRB), the process of obtaining which is lengthy and heavily scrutinized.

    2. I think because its usefulness will expire after the course is done with. Textbooks, on the otherhand, can continue to be useful after the class if said text books are any good at all. Unfortunately, most text books just flat out suck and I’m quite mystified by the choices a professor makes choosing the text. I had a few pretty sneaky professors that wanted to get on board of that money wagon. One would sell us “customized” text and test packets. Another who sold us custom MC68HC11 boards.

      1. Buying a book written by the professor teaching the lesson is about as bad as it comes. We’re already paying them to tell us what they know verbally. I can write it down myself, thanks. Especially when that book is a collection of jokes and tedious explanations of why the teacher thinks they are funny. That class was a HUGE waste of time and money. How did he even get a job??

        1. Most of my years were pretty bad. The SOAP course was taught by an engineer that designed parking lots. The XML text she picked out was better suited to start a fire. The school dropped the UNIX course in favor of Windows NT. An astronomical waste of time since the first semester consisted of learning basic shit like IPV4 structure. While my first semester with UNIX saw the students build a worm to dump the campus servers netting us quiz and test results.

          The worst ever piece of advice I ever got from a professor..? “you don’t need to optimize your code.”

          1. oh man.. thats pretty bad. i just had some students whose presentations i checked (english isnt their native language), and their regular teacher told them to use google translate. wtf?!

        2. “I can write it down myself” – yes, sometimes. Some professors have a way to write on the blackboard which makes this quite difficult. I also have difficulties in understanding the whole stuff, thinking it over, if I had to concentrate too much on writing it down.

    3. Spending money in education itself is supposed to be a *good* thing for yourself, but when it comes to proprietary systems (clicker) and freaking expensive textbooks I start to wonder whether this is that good. I do agree that materials (and knowledge) applied to building a book (and in this case a clicker) is worth money, but!. It is just that a clicker is a teacher-aid, not an educational-aid

  4. Depending on the university, they may or may not foot the bill for the clicker and the registration fees to use them. Pursue University paid for all of it (2005-2009), whereas Northern Illinois University College of Law did not (2009-2011).

    1. Hi! I’m the author of this project. If you check out the post, Taylor Killian did exactly that (you can download a sketch). I would like to do the same thing and make it a little cleaner now that we have the RF24 library. Next project idea is to hook it up to a Pi Zero with a slick web interface, but finals are just around the corner right now, so it’s not the highest priority… :).

    2. you read my mind, I was about to post the same thing. They didn’t have these when i was in school but if I were in school now an SDR, a little time and a script that purposely gets the answer wrong 10% of the time would keep me under the radar.

  5. Huh, weird. At my uni – whenever a prof wants to use these clickers – there is a box full of them that are handed out to all students at the start of the lecture which then have to be returned at the end of the lecture. They’re essentially property of the uni – as it should be the case.

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