Tie And Jeans

Electronics Kits and Bits

Kits make electronics accessible by simplifying along two distinct axis.

The first is component selection. Kits offer a cultivated garden of parts that all work properly with each other, avoiding the bewildering Digikey page or the haphazard component drawers at RadioShack. Different systems stake out different positions along this axis. Squishy Circuits (to the extent that it’s a kit at all) simply offers generic components with fat dough-friendly leads. Hummingbird Robotics boards have easy, labeled terminal blocks and come bundled with commodity parts. At the low end of the spectrum, kits include parts to indicate a stable starting place, but they don’t build fences. Systems that aim for openness create a substrate that still works with plain/“bare wire” components. This covers everything from a simple breadboard to conductive dough and the unpattentable springs of 101 Experiment kids. Forest Mims’ excellent Electronic Learning Lab offers all of these, along with integrated LEDs and potentiometers. The Electronics Learning Lab was a longtime Radioshack stalwart, but is currently, lamentably, out of print.

What restricts learners from selecting or making use of other parts is the way a kit/system decides to simplify connectivity. I suspect that this is also the major area where designers can apply trademark and patent restrictions to their systems in an attempt to prohibit “knock-off” competitors.

Closed systems encapsulate individual components, which improves users’ first circuit experience and ensures that all parts are reusable. However, anyone looking ot replace a missing ingredient or add new ones are locked in to the kit vendor’s store.

Circuit Stickers from Chibitronics occupy an interesting position in this quadrant.
Individual components come on sturdy but flexible pcbs, backed by z-tape reusable adhesive. The basic kit has a wonderfully designed workbook and includes a roll of copper tape on paper, but nothing about the component design restricts how they can be used. Each tiny sticker even has wide solder pads! Chibitronics even includes a spare sheet of conductive backing for components that lose stickiness over time. Jie and Bunny’s design is a marvel of simplicity and economy. Currently, the Chibitronics website offers 24 packs of LED sticks for fifteen bucks. That’s a price lower than the horrific RadioShack markup on standard through hole 5mm LEDs, which no one should ever ever pay, but we often do. The same pricing extends across the Chibitronics line, from the programable Attiny stickers to sensors. Chibitronics offer custom components that are simple to connect without locking the user in an exorbitantly expensive walled garden.

Which brings me to LittleBits.

I’ve been deeply intrigued by and frustrated with LittleBits for about two years. At this point, I think the Reggie Watts commercial for the SynthKit does the best job of capturing the excitement “snap together amazing things!”

Stoked? Great, now look at this.

Screen Shot 2014-05-21 at 10.53.52 PM

I’ve heard LittleBits described as a “learning electronics” kit, and never felt it was accurate. Their proprietary magnet-snap connections pushed both simplification factors so far that they seemed to rocket out of the electronics kit quadrant. Components were so simplified that few productive mistakes remained for the user. There’s nothing to observe in a LittleBits creation about how circuits are designed. Then there’s the price. A “class set” of LittleBits rings in at several thousand dollars. I’d seen students enjoy the momentary experience of playing with LittleBits, but since the high price-tag meant that all of the parts went back in the bin at the end of every class, I never saw work pass beyond the “kinda neat” stage.

With the release of the Arduino Bit, I feel like LittleBits has fully abandoned the “learn electronics!” category,or maybe they’ve just hit escape velocity. Instead of a over-engineered electronics kit, they’re offering a portal into psychical computing in a radically divergent form factor. LittleBits offers the same kit benefits (connectivity, part selection) and provides and access ramp to the Arduino “prototyping platform.” LittleBits allows users to focus on the hard fun of designing physical computing systems to make use sensor data, wether through simple logic gates or a full Arduino. Like all other micro-controllers, there’s electricity at work, but the user is hidden away from almost all of the electrical engineering.

Under the Hood

Laura is a smart cookie.  The voltage frustration that emerged from the intersection of batteries and LED series is entirely a matter of exposure.

The problems she details in this thread exist at a level of electrical detail that she’s never needed across years of learning to code, teaching CS, diving into and teaching physical computing, coaching a whole variety of robotics teams, and renovating a house! Big tools or appliances might draw to much current and blow a fuse. Robotics are designed for and often ship with specific batteries and polarized plugs. All designed, commercial systems are careful abstractions that do their best to constrain the users exposure to the confounding detail and complexity. Smart engineers have gone to incredible efforts to make the user experience feel closer to redstone than 6.002.

A major contributor to this layer of abstraction is the cheap, accessible ubiquity of micro-controllers and other discrete logic systems. This creates unified circuits that use electricity as bounded signals. In these circuits, failure occurs when signals are blocked or interrupted, but rarely every as a result of signals that fall outside a component’s expected/acceptable range.

The heart of Laura’s LED problem was a circuit that could be closed and complete, but still not function. It’s not that this is complicated, but that behavior is orthogonal to the “blink sketch” mindset.

So that’s it, right? Here’s the great example of why #makered novices need some “real” electronics knowledge.

I’m still skeptical. Clearly, there’s a good lesson lurking in here that could be packaged up neatly into a bag with LEDs of various Forward Voltages and a small pile of batteries. Blow a single LED with a 9v (actually a step in the great Make: Electronics book), have a 3v coin cell power two small red LEDs but fail with two blue ones, compare series vs parallel circuits with copper tape. I think that’s probably enough hands on experience to convince a novice to check Adafruit’s Circuit Playground app when a LED circuit doesn’t behave as expected.

My skepticism about the value of “real” electronics knowledge for novices in 2014 comes from how complex the picture becomes when we look under the hood of digital logic assumptions.

Vanishing Electronics

In this course, students discover the basics of electronics design and assembly. They use this knowledge to build their own simple flashing LED using solder-free breadboards. By diving into the assembly of these projects, students learn about impedance, resistance, conductivity, and circuit design through personal, hands-on engagement, opening up incredible possibilities for creative projects.

That was the first description I wrote for what became our Makers program. This was a perfunctory bit of text written a year before our first class, tossed onto a Google form and into oblivion. The audience was exclusively parents, crassly intended to trigger connotations of learning and complexity for an unproved course.

In that first year we did some of what that blurb promised, but it wasn’t the focus of the course at any point beyond the second week. We built Squishy circuits and made 555-based projects, but I guarantee I never used the word impedance in class.

That same year I took the first MOOC version of MIT’s 6.002. Well before we hit the midterm, I was struggling to keep up with increasingly complex circuits, dusting off my integral calc skills, and churning through paper at a fantastic rate. Coming home from teaching Makers to a new lecture or problem set triggered new waves of teacher-panic. Had I really promised to teach this material to 7th graders?

As part of the FabLearn cohort, I’m exploring broad plain of electronics with an eye on how it fits into the modern/developing #makered landscape. It’s got to be central, right? Even though we advocate for the value of cardboard prototyping and physical construction, the big name tools are all complex electronic systems.

Well, maybe not.

From the 70s into the 90s, there was a rich field of interesting projects and creative experimentation that was only open to people with a functional literacy in electronics and electrical engineering. My sense is that in the last decade, the growth of cheap, flexible, accessible micro-controllers has taken control of the sophisticated projects that used to drive students deeper into electronics. While that trend leaves the electronics domain with fewer “exclusive” projects, the hurdles facing a novice haven’t changed much. While the internet makes it easier to share schematics and video tutorials, electronics still requires parts and precision. I can download the schematics for a transistor radio or a preconfigured disk image that transforms the RaspberryPi into an FM Transmitter.

Deep electronics knowledge opens up incredible possibilities. I’ll submit as evidence any of ch00ftech’s posts or Jeri Ellsworth’s Short Circuits. But in an Arduino-rich world, there’s far fewer low-end projects that require those skills. Instead, those electronics skills become mandatory when a project needs to exceed the constraints of what’s possible with a micro-controller. When a project needs to use less power, take up less space, respond with less lag, scale out at with less cost, then you’ll need the skills to design and build complex, task-optimized circuits.

Here’s the chicken-egg of learning electronics in 2013. Every basic circuit in a Forrest Mims notebookcan be duplicated with an Arduino and a tiny selection of components, using copy-pasta code and breadboard illustrations. In that world, how much discrete electronics knowledge does a novice need?

In the months I’ve spent looking at this problem, I’ve slammed repeatedly against a cognitive wall. I examine my practice, the projects my students pursue, the projects shared throughout the wider #makered community, and I see a role for electronics that’s smaller, more constrained and highly task specific. When I interrogate those findings, I keep coming back to a enduring conflict. Are my observations accurate, or does my weak understanding of electronics obscure a larger and more complicated story?

I can’t be sure. I’ll be sharing my look into the current market of “learn electronics!” kits in a later post, along with exploring the uneasy border between circuit simulators and Minecraft. But throughout those, know that this question – am I missing the real story? – lies under every observation.

Maximizing School Interviews

This is the tail end of interview season for teachers and schools. Since I have some distance from the process this year, I can see a few things that more obscured when you’re in the thick of it, on either side.

First off, most schools are bad at this. We’re not sure what characteristics make a great teacher, but we know resumes and cover letters mean almost nothing. Which leaves schools either trusting their collective gut (often one particular administrator’s gut) based solely on conversations, or forcing candidates to perform  meaningless game show lessons. Across the board, schools spend a ton of time and energy on the hiring process, and invariably find themselves in a time crunch where they settle for acceptable instead of awesome sauce.

Given that underwhelming reality, candidates assert themselves throughout the process. Be aggressive and use the interview as a window into the reality of a school’s program and culture.  Like the inflated single-purpose resumes, school’s public faces are often bland and interchangeable. Disregard aspirational talk. Listen for how teachers speak to each other.  Ask for 30 minutes to sit in a hallway. Observe an unrelated class. This will likely be your one pass through a building that will dominate your psyche for the next N years. Don’t sit passively on the Disney tour.

Even if you don’t have a ton of mobility during your interview visit, there is information in the structure of interviews. Try out this fake formula with the conversations scheduled during your visit…

(Scheduled Length * Role) / Number of Participants

…then sum up the totals by school role – School admin, division/building/subject leaders, teachers & faculty, students.

The group that gets the most time will be your superiors, and be responsible for assigning you tasks throughout the year.

The next group is will be your nominal peers.

The group with the lowest representation will be the ones you’re supervising. This is often the group that you see 20 of for a mere 40 minutes, either students in a sample class or a cattle call faculty interview during lunch.

If a group doesn’t show up on the list, then your superiors don’t think that your position merits much exposure or contact with them.

That reading might not hold throughout your tenure in the position, but it does approximate the school’s institutional vision for the position. Does it look fun? Soul killing?

Teachers are rightly reluctant to change jobs in the middle of an academic term. Treat every interview as your last chance to happily walk away from a bad fit.

Learning Cycles

Last week, Josh Burker posted a picture of a MakeyMakey “violin” designed and built by one of his elementary students. It’s a great bit of prototyping, using stretched wire and a metal bow to trigger MakeyMakey inputs.

But this student wasn’t satisfied with a single sound per string, and Josh relayed that design challenge out to the #makered community.

(This post is a reflection about learning cycles and MakerEd. If you want to see the prototypes, read this instead.)

On one level, this call hits at the heart of why MakerEd has blossomed along with the growth of global learning communities. With cardboard, write and a $40 toy, an elementary student can move an idea out of her “invention journal” and into the real world. This means she can be simultaneously thrilled at her tangible accomplishment, and frustrated by the numerous limitations and compromises she’s made along the way. To iterate on that first object, she’ll need to incorporate some wholly new ideas into her intellectual framework. To complicate matters for the “just Google it” generation, she also lacks the language to describe or discover those new ideas.

Josh doesn’t have an academic background in electronics. However, he does have extensive experience taking on projects for which he doesn’t have a academic background. Josh knows that being a “life long learner” means also being a “life long beginner,” and has developed toolsets that help him address the common problems of beginning. One of tools is an expansive network of friends, colleagues and mentors.

I have a very poor academic background in electronics. However, I have experience working within a small corner of electronics problems and exposure to the wider field. Even when I can’t provide solutions, I can often help rephrase questions in language that will produce solutions.

This is the way that beginners learn, how they move into a new discipline and become novices, and then amateurs, and so on.

What starts to transform this student’s problem from a brick wall into an opportunity is her teachers’ skills and experience as a learner.

I think of this as a tide of questions flowing out. There’s another important set of skills that govern how the information flows back in.

There is an academic answer to this question. “You need to look at the board’s schematic and build or extend a voltage divider for each input.”

That should clear everything up

That should clear everything up

Depending on length, replies like this range from “look up these terms in the textbook” to “here’s the textbook on these terms.” But in no way to they offer a direct bridge to help the student move forward with their idea. I’ve made this mistake too many times with students, in math and Makers, where I’ve asserted the existence of firewood instead of starting a flame.

Growing up with cooking shows, I know there’s a trap at the other end of the helpfulness spectrum. “Mr. Pepin, I was wondering what I could cook with all these rutabagas?” “Well,I happen to have this tray of roasted rutabagas and porkbelly in the oven now!” Which is great if you’re hungry, but doesn’t actually help the person with a wheelbarrow full of rutabagas. Even providing a recipe can send the incorrect message. “I guess vegetarians can’t eat rutabagas.” When teachers do this in math or CS, we insist that students can learn by dissection, carefully examining this particular solution for tools and techniques that will suggest general principles. But when you’re a beginner, you often lack enough domain specific context to determine which ideas are load-bearing and which are ornamental.

While there’s satisfaction in executing a recipe or assembling a kit, it’s fundamentally different from building and improving your own design.

I don’t think there’s a universally appropriate midpoint between these two extremes. The teacher’s role is to use the information flowing in to craft the best solution for this beginner and this domain. Teachers get better at reading the needs of a learners over time, as well as building up a wider range of domain knowledge. Over time, learners get better at recognizing when they need more support or when the instruction becomes overbearing.

For the three of us dancing around this Scratch dobro, I’m finding the limitations of Twitter, Vine and WordPress to be helpful fences. Even in the rough prototype I built, there’s so many design choices! I keep my work ugly, so that no one can mistake it for a finished product. I know Josh will ask when he has a new batch of questions.

Violins and Voltage Dividers

This is a quick project sketch, building on a conversation with Josh Burker. It’s a reference, not a tutorial.

This is probably possible using the MakeyMakey’s analog input ports, but the Picoboard’s resistance sensors are a better and more direct choice.

This was my first prototype. Apologies for the sideways video.

This just uses a few resistors in series along a span of copper tape. After checking that the values were distinct enough, I had the Scratch instrument play the resistance value as the note. This is probably a bad plan for actual music. :)

Josh asked for a string that could be fingered to change pitch, while the “bow” played in the same place.

violin string

This is random wire, wrapped around popsicle sticks at either end of the cardboard tube and taped in place. The kinks and bends in the wire are no good, but the concept is sound.

I attached one clip form the Picoboard to the bow, and one to the copper tape + resistor strand. The key is that the wire/string doesn’t touch the copper tape at all. If you touch the bow to the string, you don’t complete the circuit.

In order to get any reading (ie, resistance less than 100 in Scratch), you need to pinch the string to the resistor+tape.

photo 2 (1)
You need a multimeter for this. The Adafruit Circuit Playground app would also be a helpful, between checking resistor codes and calculating the voltageOut.

Making this into a stable instrument is hard work. What voltage range can the PicoBoard sense? How do those values map to Scratch’s 0-100? How do those 0-100 values turn into pitch? What size resistor makes a good step? How many “frets” can you fit on the neck of your instrument? How close together do you fit the strings? Does fingering a chord produce a clean combination of tones or something else? Do you keep the fingers on your chord-ing hand electrically isolated? Does the bow need to be isolated?

Those aren’t facts to discover, but choices that will shape design. You could give that framework to 50 kids and wind up with an orchestra of different instruments.

photo 3

photo 2 (2)

photo 4

Hunting Microworlds

One of the most difficult part of reading Mindstorms in 2014 is pacing yourself through the long sections where it seems like Papert is simply explaining LOGO to an audience that has never owned a computer. There’s a natural tendency to skim at these parts. We may not have wound up with the powerful computing future that Papert envisioned, but many of us went to school through the LOGO boom and have taught using Scratch, Turtle Art and MicroWorlds for a decade or more.

This time through, I tired to read those sections more carefully. While the physics Turtle and Geometry Turtle examples were still very familiar, I was struck by the fact that I couldn’t think of a huge collection of other software microworlds.

Prompted in large part by my work with FabLearn, and my own late start with electronics, I’ve been trying to imagine what a true Papertian microworld for EE would look like.

I’ve seen a number of circuit simulation tools used over the years. I remember using Circuit Construction Kit with students in my first tech+teaching job, but there are plenty of others. However, this reread of Mindstorms has overturned my assumed relationship between simulations and Micoroworlds. In my cursory review of simulation tools, I didn’t see anything that offered the richness that Papert asks of “idiosyncratic microworlds.” Simulating circuits requires less physical dexterity, eliminates the cost and hassle of procuring parts, and allow fantastic “point-wise” inspection of elaborate systems. But they all fundamentally present an idealized form of the physical world. When used in context with circuit simulators, the world “simple” refers only to the number and function of individual components, not to the underlying principles that govern the simulation.

Then there’s Redstone.

Redstone is the building material for electrical analogs in Minecraft. I recorded that video in the summer of ’12 (aka ds106 SummerCamp!), and you can hear my apprehension in the first 30 seconds. Here’s this thing that’s kind of like electricity, which means you can build things that are kind of like circuits…. but they’re not real!
I couch my discomfort as teacher-fear, of not wanting to push my students down an “incorrect” path. In reality, that discomfort is coming from the friction between my own hastily and poorly constructed microworld of electronics understanding and the structure/function of the redstone. I didn’t have a deep and nuanced body of EECS knowledge that I was disappointed to see unrepresented in Minecraft. Instead, I had a half dozen beliefs that I had hung into a loose scaffolding, but individual components were flimsy and couldn’t bear my weight.

Does Redstone constitute a learning microworld for electronics? As a brief overview, the Redstone “circuits” offer a purely digital system, where a wires and component can only be powered or unpowered[0]. There’s no analog for voltage or amperage, which means that there’s no equivalent for capacitors, resistors or transistors. Redstone signals propagate in neat 1/10 second hops. In short, there’s a robust system that can produce wonders, but a student who only studies Redstone will fail a 3rd grade multiple choice quiz about electricity.

Papert’s microworlds aren’t judged by the richness or complexity of the objects that can be produced within. It’s lovely that the Geometry turtle can create wonderful art, but the value of the microworld isn’t dependent on whether the learner created the AlHambra or a box house. In a sense, the Papertian value of a microworld comes from how it can evolve in response to the learner.

There’s certainly a thriving world of Minecraft extensions, many of which extend the redstone system or build up alternative signaling/power system within the same blocky world. But the tools used to create those mods are wholly distinct from the in-world construction tools. Minecraft utterly fails the challenge offered by LOGO, LISP, and Squeak, and offers no path from being creating within the game to creating/modifying the game.[0]

The other criteria for evaluating an microwold is how it exposes learners to “powerful ideas” and if those insights/experiences can transfer to other microworlds or other learning domains. This forces me to realize that I’m not sure what the powerful ideas at the heart of “electronics” are! My list looks similar to the Nell’s insights from Castle Turing throughout King Coyote’s realm in Stephenson’s Diamond Age. Complex systems are often simple systems in aggregate. Careful design makes powerful tools from tedious processes. There’s nothing on my list that looks like a learning objective from 6.002.

My stance is that powerful microworlds don’t have to teach Ohm’s Law, but prepare students to seek out and make use of Ohm-like Laws.

[0]Or maybe not! Since the last time I build redstone circuits, Minecraft has added power levels to Redstone, including components that respond to those power levels and direct comparators

[0] There are some confusing edge cases to this. The RaspberyPi edition of Minecraft exposed an early API, with Javascript and Python libraries, so that players could write/run code that would affect the Minecraft world. There’s great examples of this tool bridging the digital/physical divide, making a light switch in Minecraft that triggers a set of LEDs in the real world. Scriptcraft goes a slightly different direction and exposes the Minecraft API to Javascript commands typed directly from the in-game console. Not that the console line is a pleasant text editor, but it does close the loop and allow for modifications to the game system from within the game itself.

Launching Makers: Students

I spent most of my time at NAIS with a great team of Maker-minded educators, each of whom has great stories about the growth and accomplishments of their program.

When I watched the faces of other teachers and school leaders in those conversations, I could see the analytic processes running very close to the surface. They were listening to these (hopefully) inspiring and entertaining stories, but only because we were too stingy or too dense to simply explain how to launch their own #makered program!

After retelling my story from Flint Hill, and listening to Jaymes, Lindsey and Vinnie retell their origin stories, here’s the Cliff Notes for launching a K12 Makers program.

These are the three resources you absolutely [1] need in order to launch a #makered program:, students, faculty, and space. The precise mixture and composition of those components will dictate the starting boundaries and possibly the focus of your program.

Students are the most difficult component. Not because individual students lack interest, but because of how schools limit their options and constrain their choices.

Most K12 schools wrap all student and teacher activities around a carefully managed framework of classes, breaks, passing periods and coverage. From one viewpoint, a school’s primary resource is student hours, and the whole edifice exists to portion out students and move them smoothly from place to place. In the vast schedules that constitute those systems, very few cells are dedicated to “you know … whatever seems cool.”

Student contact hours are often set up as a zero-sum game, where established players (rightly!) view new programs as immediate opponents that could develop into existential threats. New programs don’t bluff their way through the curriculum and schedule gatekeepers with a gameplan of “just start!”

But while most schools have a carefully managed schedule, almost all of them are held together with some kludge. If you’re looking to launch a Makers program “Monday, not someday” then look for these areas. At Flint Hill we started with middle school study hall, a weird schedule-filling block that didn’t serve an academic purpose beyond “kids go here.” This year, we’ve seen great uptake Makerspace use from middle school students who are dismissed at 3p but have to wait for the 3:50p bus routes. Every school is different, but I’ve yet to find one that doesn’t have some pockets of time where the primary mandate is “have an adult in proximity to kids.” Not only are those times fundamentally unclaimed by the faculty structure, they’re often a real drag for kids as well! Providing a Makerspace alternative to those “holding pen” moments is pure upside for the students and the school.

When you’re looking to launch a K12 Makers program, start with finding a time that students can make. If you can’t find a window for it now, then you’re facing a problem that no capital campaign or architectural design team can solve.

[1] I’m on record as a“just start” absolutist. This list, like any attempt to three-ring binder and package the #makered process, is a compromise from that position. Please imagine that every noun and most adjectives that follow have invisible asterisks, footnotes and disclaimers.

Creating Space for Success

It’s 12:40. There’s maybe 15 minutes left in class. The three closest projects to me are a student laying out measured 2×4’s to cut with a circular saw, another drilling angled holes into some laminated planks for an atatal, and the grisly disassembly DVD changer covers much of the floor. Somewhere outside my cone of vision there are 6 other projects, none of which (thankfully) are using a tool more dangerous than a soldering iron.

I turn around and see two young women, holding an untidy bundle of butcher paper, their project box and a can of spray primer.

One of the weirdest parts of teaching middle school is recognizing the places where your immediate adult presence is a part of the solution and where it’s part (often a large part) of the problem.

Sandy Snively, an incredibly generous and gifted mentor that I did not deserve, believed in the space teachers create by their absence. She taught me all of the best things that ever happened in my math classroom, one of which was to take a long walk, straight out of the classroom, during  tests.

“Is that honor code horse-pockey, or does it mean something?”

Students in her classes created an honor code together in the fall and signed their name to that same pledge on every test. Sandy knew that kids signed other honor codes, in classes where the teacher still prowled through rows of desks during the test, eyes peeled for a forbidden note card or furtive glance. Those honor codes were horse-pocky, and those teachers damaged their students with every circuit.

Adolescents observe their teachers closely to discover the meaning and value of their own actions. Sandy showed me that our students learn how valuable their words and commitments are by how adults respond to them. The prowling teachers told their students that honor codes are just words, a thing you bubble in and forget about, no more binding than a COPPA checkbox. Sandy told students that words matter, that we come together in community with principles above “what can I get away with?” Her faith in her students shone through every time she’d stroll out of the classroom to get a cup of tea, opening a space for their integrity to emerge.

I can see a dark gray mess through the window and hear lower school kids tromping through the halls towards lunch.

“Go. Tape down two feet of paper on all sides of the box, and try to get back in the building before class ends.”

There’s plenty that could go wrong with two 8th graders and a can of spray paint during the middle of the day. But chasing down every possible problem also ensures that I’ll fill up the space that these amazing young people need to discover, make, and thrive on their own.



* Sandy was a salty farm girl to the core, even in her middle school classroom. She never, ever, said horse-pockey.

Kid-focused #makered Integration

I struggle to find ways to integrate my #makered work with other 7/8 classes. If teachers have a prep period, it’s during our elective block. Also, when push comes to shove, I’m not sure the 3×45 minute #makered experience is actually #makered. Not to get all maker-tao on this, but it’s something I worry about.

Instead, this year I’ve taken advantage of the multi-year relationship I have with many of these kids, and have started to lob interesting things at them via email. As the curricular tech guy when they entered middle school, I’m very likely the first person from whom they received an “official school email.” Sometimes I’m sharing choice bits from my #makered links collection. Other times, it’s a particular problem or project that’s active in the space.  Here’s one I sent today to a few of the more puzzle-minded 8th graders.


I made a mistake, and I could use your help.

This will sound like a math problem, but it’s not.  I mean, it’s a problem, and I think that math’s probably my best hope to solve it in a way that doesn’t involve undoing and redoing hours of tedious work. That’s actualy, physical, with my hands work! Ugh.

But importantly, this isn’t a problem from the back of a book. This is something that emerged from a weird combination of design, technology, and cultural habits.  Oh, and mistakes I made.  Because I was in a hurry and didn’t check my work as I was going.

There’s pictures to go with this, but they may not show up “in line” in Gmail.

There’s a clock project in Makers. It’s pretty cool. It will show the hours by turning on individual lights at the end of the little arms.

Photo on 2-18-14 at 2.26 PM

These lights are arranged in a chain, or strip. This is useful for a bunch of reasons, but the most relevant is that you can turn any of them on/off by referring to it’s position in the strip.

There are 12 lights in the strip (because, you know, clock) but they’re numbered from 0 to 11 (because computers).

Photo on 2-18-14 at 2.26 PM #2

Here’s my mistake. Because I was looking at the back side of the clock while building it, I wired the lights so that the order of the strip went around backwards. Dumb move on my part, compounded by the fact that I didn’t catch it until I had wired a bunch of other stuff in place.

So now the numbered lights in the strip are arranged around the clock like this.

Photo on 2-18-14 at 2.26 PM #3

This is bad.

The program reads the hour part of time as a integer between 0 and 23. That’s  0<=hours<=23 for those keeping score with interval notation

Can we find a clever way to use math, to create a rule, that maps the integers [0,23] to the integers [0,11] so that the proper light is turned on?

Photo on 2-18-14 at 2.26 PM #6


-mr carle

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