Friday, July 29, 2016

Why isn't USB universal?

Project Status: Dream cam true
Project Update: Reversible USB


There is a correct way and an incorrect way to connect a Universal Serial Bus, commonly known as USB, when it should universally work both ways.

Doesn't it always seem like when you plug in a USB it is the wrong way first, and you have to flip it over. Shouldn't it statistically be only about half the time? Well my friend, the following is the psychology behind how USB is able to appear to defy the laws of probabilities and statistics.

Actually the problem is largely because USB is built to have a small amount of resistance, for the simple reason that this is what keeps it from falling out while it is in use.

Technology is delicate, expensive and we typically don't want to break our nice little techno-toys. So when we start to plug in a USB cable or device we instinctively stop mid first try thinking the resistance is too high, that surely this must be the wrong way and we are about to break something.

So we stop. Flip it over and try the other way. Chances were actually 50/50 that it was correct the first time, but the odds are much greater that even if it was correct we stopped to try the other side just to be safe.

The tricky part about how our brains work is that even when we flip the USB cable or device over an even number of times, meaning we were right the first time, we don't remember it as such. All we remember is how it didn't work. Which is the sketchy math that made our odds of being correct on the first try appear to drop.


It's so simple, design the cable or device so that it works both ways. With both of the two possible ways to attach the USB correct, the first try is always right.

I really need to show some diagrams here so you can see what I mean but with the ability to make such tiny hardware I wouldn't think it would be very hard at all to make this possible. No changes need to be made to the existing hardware which you plug a cable into (the receiving end), the only changes should be in how USB cables and devices such as thumb drives are made.

Hopefully there are companies out there already doing this, but I haven't looked around so I'm really not sure.


Turns out people are already selling the type of USB connections I was imagining. Check them out here in the update about reversible USB cables.