Tie And Jeans

Archive for the tag “guru”

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.

Advertisements

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.

Post Navigation