Wiring is one of those things that we’ve all had to do on a project, but probably didn’t give a lot of thought to. It’s often the last thing that happens during the build, and almost certainly doesn’t get approached with any kind of foresight. You look at the components you need to connect, dig through the parts bins until you find something that looks like it should fit, and tack it in with a blob of solder and perhaps some hot glue if you’re feeling really fancy. We’re all guilty of it from time to time, but Bradley Gawthrop is here to tell you there’s a better way.
If you’re hoping his talk from the 2017 Hackaday Superconference contains “One crazy trick” for turning your normal rat’s nest of wiring into a harness worthy of the Space Shuttle, sorry to disappoint. Bradley acknowledges it takes some extra planning and a couple specialized tools, but the end results speak for themselves. While his talk is a must-watch for anyone looking to master the arcane arts of electron corralling, his post-talk chat with Elliot Williams after the break is a great primer for the how and why of everyone’s least favorite part of building their own hardware.
Bradley will be at Supercon again this year. It’s one anecdote for the concentration of awesome people you find at the event. We’re now just two seeks away so go get your ticket and then join us after the break for the interview.
Bradley knows most of us don’t share his love for wiring harness, and that’s OK. He doesn’t knock anyone who’s still in the breadboard phase of their electronics careers, after all, we all started there. But he does think that wiring has gotten a bad rap. There’s a feeling out there that it’s too hard, or not worth the effort, and that’s the key thing he’s trying to address with his presentation.
How many times have you purchased pre-made wires and cables and tried to shoehorn them into your project? Or cut one end off of a cable so you could strip it and solder the individual conductors to a PCB? Bradley has seen it all, and he says more often than not it leads to difficult to diagnose gremlins. You end up spending time and effort trying to track down a bug in your device, only to find out it’s a cold joint in a cable you tried to splice in a hurry.
He should know: he spent a decade wiring electronic organs which are controlled with a dizzying array of solenoids. When a sizable chunk of your professional life is devoted to putting together thousands of made-to-order wires and harnesses, you can’t help but pick up some tricks; not to mention develop a keen eye for identifying potential points of failure.
So what’s Bradley learned? He says that standards like solder and screw-down terminals work well enough in the short term but will always lead to heartache. Solder is brittle, and the ever popular screw terminal eats wire ends for breakfast. But on the flip side, he says you don’t have to go and buy the most expensive crimper out there just to get decent results. He says he’s done thousands of crimps with the sort of consumer-grade gear you can get on Adafruit; there’s no need for NASA-spec tools just to put together your next DIY project.
This is just a taste of the sort of real-world wisdom on display at the Hackaday Superconference every year, so get your tickets for this year’s rapidly approaching Superconference before time runs out.
There is nothing like wasting a bunch of time and finding out it is some flakey connection problem. If you haven’t been there, you probably haven’t done much of anything as far as building electronics. Cables and connectors are pretty boring but extremely important.
“Bradley knows most of us don’t share his love for wiring harness, and that’s OK. ”
Maybe it’s an ADD thing?
Yeah, what? Some of us love wiring and think of it throughout every stage of the project.
I spent 20 years as an electronics designer in the aerospace industry and every major delay in a program I worked on was due to a poor choice of connectors or inadequate validation of wiring. Doing the dog work of selecting good connectors and checking wiring lists can be unexciting, but is a key to successful projects.
100% of people who like this article would click this link (yes, it is SFW)
https://www.reddit.com/r/cableporn/
The choice of connector does depend a lot on how the equipment will be maintained. If it is a field installation, I find a ferrule based, cage type screw terminal to be very useful, as he technician always has a screwdriver on hand.
If you want to be nice you can use terminal plugs so if you’re doing a like for like swap it’s really simple but you’ve still got that screw terminal for the rest of the time.
(Bradley Gawthrop here) Absolutely! I’m not actually opposed to screw terminals in many cases, as the talk itself says I’m mostly against the (predominantly American) practice of putting bare wires in screw terminals without ferrules. That’s trouble! But with used with ferrules they can be reliable and user friendly – witness their heavy use in industry. A cabinet full of DIN rail is almost inevitably also filled with screw terminals for the very reason you point out. Cheers!
Yes, the pluggable types are great. In cost sensitive, high IO count applications, I often, unfortunately, have to abandon them, as they can be a little pricy. One thing that I have NOT done so far (in 20 years) , is to use the cheap screw onto the conductor types. Although they tend to be a little larger, and more expensive, the cage type really is worth it. If you are unfamiliar with the operation, tightening the screw does not squeeze and cut directly into the conductor, it raises a cage that the the conductor is in. Squeezing it against a firm fixed roof. This results in a contact that minimises the surface damage to the conductor.
Screw onto conductor just seems to be such a bad idea yet nearly every mains socket /switch in Australia is that style. Along with cutting the conductors often only a few strands are actual gripped by the screw.
really looking forward to the tutorial on cable lacing techniques!
Here’s my “one crazy trick” to clean up your wiring:
Use less wires! Whenever you have a connection between two units, or something meant to be unplugged, etc, you can probably get away with only four wires. Power, ground, data+ and data-. CANBus chips can be used with normal UART for a cheap custom bus protocol. I2C can usually handle anything under a foot just fine. Microcontrollers often cost less than connectors, and with low frequency signals you can often just run parallel wires. Cat5 can provide redundancy on both power and ground.
On top of that, there’s always WiFi as another redundant digital channel.
Sending lots of different power voltages over long distances is a bad idea. If you have tons of teeny tiny 5V devices, fine, but don’t go sending individual RGB color channels across a building without good reason.
There’s almost certainly power nearby where the lights are, just use DMX. Low voltage wiring is bulky and copper is expensive. If you’re using batteries, put the battery with the load, and don’t try to cover more than 12ft or so with low voltage.