Background
About a week ago, Hackaday hosted the Superconference. Dubbed the “greatest gathering of hardware hackers, builders, engineers and enthusiasts on the planet”, it featured talks on subjects ranging from 3D Printing to Security to Augmented Reality (AR). Media outlets jumping on the tech buzzword of the day would undoubtedly have had a field day if they had just copied off the list of talk titles.
While Kitty Yeung and Pat Dooley’s talk introducing Quantum Computing serve to remind us of how little of the potential of computing we have uncovered, it was Mike Harrison’s talk on LEDs that first caught my eye.
LEDs and the Maker Movement
The Maker movement has democratized technology, giving just about anyone in the developed world the means to develop projects that, not too long ago, were only possible in research labs. Financially, the cost of goods (sensors, actuators etc.) and services (PCB fabrication, tooling etc.) are only getting lower by the day even as quality continues to improve. With Makers now representing a large enough market, the sale of such products has expanded from being predominantly Business to Business (B2B), to include an ever growing Business to Consumer (B2C) channel (check out this post for our take on the best Black Friday/Cyber Monday deals around). The importance of this development cannot be understated as lowered cost could not have fueled the growth of the Maker movement if the average person had no means of buying these goods and services in reasonable quantities. Coupled with the explosion of technical material once reserved for students of Engineering and Computer Science at the tertiary level within online and physical communities, it is understandable that a growing pool of individuals who believe they have attained a considerable level of mastery in various technical domains (just look at how many tech start-ups we have making radical promises!).
Arguably, the LED is the most recognizable icon of the Maker Movement in spite of the transistor being the bedrock of modern day computing. This is hardly surprising given the fact that most Makers share the same introduction to the world of electronics, learning about digital signals by blinking LEDs, and “analog” signals by fading LEDs in and out. This path is brilliant in its simplicity. With just a single component, learners overcome their psychological barriers, lifting some the dense fog that obscures the inner workings of the gadgets we use everyday. It is the beginning of one’s transformation from Consumer to Creator.
Everything I’ve Learnt About LEDs
“45 minutes? I’ll just skip to the end to hear the parts I might learn something from”. Ok, no one’s actually told me that yet but my years as an educator and a student of engineering leads me to believe that the average Maker won’t have a reaction too different (varying my sentence structure also keeps the auto SEO analytics happy). If you were so inclined to jump ahead, I would strongly advise against it, unless you happen to be Mike Harrison himself, or someone who works with LEDs for a living.
Throughout this amazing talk, Mike covers everything he knows about LEDs from the impressive list of professional projects he has undertaken, and, I would suspect, a lot more time outside those researching and iterating. Ever needed more brightness and instinctively grabbed a replacement from the Super Bright pile? Ever tried getting white light out of an RGB LED, realizing how difficult it is, and chalking it down to factory mis-calibration you can’t do anything about? Mike has the answers. After answering your simple questions, Mike then goes on to bamboozle you with the complexities of high performance LED work. At this level, where the fade of an LED must not look the least bit discrete, time is measured in the nanoseconds and the audible noise produced makes or breaks a design.
Aside from the technicalities, Mike’s talk reminds the Maker about how much more there is to learn. It is an insight to the difference between hiring an intern with “built and controlled LED circuit” on their CVs and a professional who might cost a thousand times more. It is a warning to the start-up founder who’s built a prototype that “just needs to work for the demonstration” who thinks they’re just going to need “more of the same, but bigger”.
A Quick Tip
Apart from the ability of LEDs to add visual appeal to any project, they are also extremely functional as simple, binary, debug signals or status indicators.
For a recent project, my team and I developed RAID (Running AI Development Platform), which aims to do exactly what its name suggests. Capable of running at over 20km/h with built in collision avoidance, it is a high performance system that needs to react on the millisecond scale, carrying enough energy to seriously injure anyone around it in the case of a system failure.
LEDs were deployed on this system for multiple reasons:
1. Encoding of Mode through color
2. Using fade frequency to encode information such as warnings, the distance of the robot to the closest obstacle, and the recommended breathing rate of the runner
3. General visibility
While there was nothing particularly complex about this LED setup, getting a smooth fade on a system with variable loop times could not have been done just following a generic fade tutorial. However, as the LEDs were a secondary functionality, it would have been unwise to dedicate too much time developing a hardware solution. Instead, a simple software band-aid was applied. Rather than controlling LED intensity through a counter increment, the readily available (if not the most accurate) timing functions were used to generate a PWM signal proportional to the modulo of the milliseconds elapsed since the system was powered on. Arguably, this leads to an even simpler program, and should perhaps be the way all fades are taught from the onset.
Conclusion
The Maker Movement has showed us how to scratch the surface of things, and bring technology within touching distance. Unfortunately, the ease of implementation these little projects hides the complexity that comes with real-world use. Sure, the humidity of your room and the vibrations from your surround sound system may not have had any perceptible implications on your breadboard circuit, but 10 years in a tropical country, or placement beside the speaker of an outdoor concert would.
As basic technological literacy becomes commonplace, it is important for society at large to build an idea of the true complexity of the task at hand in relation to the Maker, lest we build a world where everything falls apart when global temperatures inevitably rise 2 degrees, where Autonomous Vehicles claim lives when Bob, the dude with a Nanodegree in Self-Driving Cars makes a pitch too convincing for VCs to ignore.
