Chris Gammell is a guy that should need no introduction around these parts. He’s a co-host on The Amp Hour, and the guy behind Contextual Electronics, a fabulous introduction to electronics and one of the best ways to learn KiCad. If you want to talk about the pedagogy of electronics, this is the guy you want.
Chris’ talk at the Hackaday | Belgrade conference was on just that – the pedagogy of electronics. Generally, there are two ways to learn how to blink an LED. The first, the bottom-up model taught in every university, is to first learn Ohm’s law, resistance, current, voltage, solve hundreds of resistor network problems, and eventually get around to the ‘electrons and holes’ description of a semiconductor. The simplest semiconductor is a diode, and sometime in the sophomore or junior year, the student will successfully blink a LED.
The second, top-down method is much simpler. Just wire up a battery, resistor, switch, and LED to a breadboard. This is the top-down model of electronics design; you don’t need to know everything to get it to work. You don’t need to do it with a 555, and you certainly don’t have to derive Maxwell’s equations to make something glow. Chris is a big proponent of the top-down model of learning, and his Belgrade talk is all about the virtues of not knowing everything.
Chris begins his example by going through the process of building a car. In the bottom-up model, you would begin building a car by first learning thermodynamics. The top-down method of building a car is much simpler – you don’t need to know thermodynamics to build an engine, because you can just buy an engine and put it in a chassis. For every part you need, you can just go to the car store and buy some wheels, an engine, and a steering wheel.
For every electronic project you build, each piece of your block diagram is available as a module. If you need a boost converter, that’s a black box you can buy from Digikey, Mouser, or China. If you need a better boost converter, you’re still able to design your own, but you’re not starting by learning all the theory.
Chris’ solution to learning electronics isn’t learning theory and equations. This gives you tunnel vision, a simple problem – an LED that fails to light – leads to a rabbit hole of textbooks and Wikipedia. Four hours later, the student still has no idea why the LED doesn’t work and is simply aggravated. Instead, Chris suggests taking things apart and looking at how they work. This takes the learning process up one abstraction layer, and after looking at a few dozen circuits with LEDs, the problem isn’t one of remembering equations and theory. The problem becomes pattern matching. Humans are very, very good at matching patterns, making this the ideal way to learn.
Effectively, this is Just In Time learning – you don’t need to know everything at the start, you just need to know what to do to get to the next step. How do you do this? Expert systems, or more specifically, the Hackaday.io community, the EEVblog forums, or any of a dozen other electronics communities around the web.
Compared to learning a bunch of theory and then futzing around trying to get a circuit to work, Chris is saying you should dive in and iterate quickly. It’s not going to change the pedagogy of universities, but it will get you blinking an LED faster, and that’s what we’re all about anyway.