Probably unsurprisingly, we ran into our fair share of problems making the jacket, from physically fitting everything in, to wiring, to programming.
I already talked about the programming woes. And while yes, I learned more programming skills, I wouldn’t really say I learned anything “from” it – programming is a skill that I will (hopefully!) get better at over time, purely by doing more of it.
But if there was a “principle” I learned, I would say it was about the benefits and pitfalls of modularity.
From the very beginning, we strived to design the jacket in a very modular way, so that any individual component would be quickly and easily replaced. The lights plugged into cables which plugged into controllers and power supplies. Almost every component could be disconnected by pulling apart the connector – very little was hardwired.
The problem with this design however is that it significantly increases the number of failure points. If things were hard wired, there would be one continous wire soldered at one end onto the LED strip, and the other end onto the Arduino board. That’s two potential breaking points, where the solder connections are (I suppose the wire itself could break too). But then you’re very limited – if a light dies, you have to pull out the soldering iron. If the board dies, you have to unsolder ALL the connections. You can’t upgrade components, etc etc.
The modular path we had was like this: LED soldered wires -> JST male plug -> JST female plug -> short pigtail-> crimped to long wire -> DB9 male plug -> DB9 female plug -> Arduino board screw terminal. That’s… 8 connection points? 8 is more than 2.
Not only were all those connections time consuming and error prone to make, we definitely experienced some reliability issues.
If I do a version two, one thing I’ll definitely invest in is the proper equipment to make my own JST (or similar) plug terminations. That would eliminate several connection points – possibly bringing it down to as few as 4 points. 4 points and modular is a good tradeoff compared to 2 points but not modular.
Will I do a version two? I don’t know yet… But I’m definitely thinking about it!
