What kind of wire can I use with ManT1S?

The official story

One thing that may be confusing about T1S is that you can't really go to the store and buy a "T1S cable". For standard Ethernet, on the other hand, it's easy to find pre-made Cat5e or Cat6 cables, or to crimp a couple of RJ45's on a length of cable yourself.

All that's really specified for T1S is that it's "Single Pair Ethernet", so you officially need a single twisted pair with about 100 Ω differential impedance. Although there are various connector manufacturers trying to make you buy into their expensive connector families for SPE, I decided not to wade into that quagmire as it seems this discussion is far from settled, and paying as much for a cable as you pay for a ManT1S seems preposterous.

Luckily, it turns out that the solution is quite simple, and T1S is very forgiving when it comes to the wiring it can work with!

What I decided to use

Since there is no clear standard or winner for a T1S connector, I decided to just use screw terminals. They're easy, cheap, and everyone knows how to deal with them. Compared to some of the SPE connector options that manufacturers are trying to push, they also have the advantage of being nice and compact, taking up little board space. An important consideration for a tiny module such as the ManT1S!

Now when it comes to screw terminals, I am very picky. There are some good ones and then there are ones that I loathe deeply. The ones I loathe are the ones where the screw pushes a flexible tab down on to the wire. You know what they are also good at? They are perfect for shoving the wire out of the screw terminal while you're trying to tighten it down! Here's an example of what these abominations look like on the left:

The ones I like, and integrated on the ManT1S, work differently and are shown on the right. When you tighten the screw, it pulls a little square metal cage up against the top contact, which works great! In the picture, the left two positions are tightened (cage up) and the right two positions loosened (cage down) to allow you to insert a wire. They solidly grab the wire, without trying to push it out while tightening.

As for the wire itself, much of my testing and the wiring for the campaign video was done with this nice 24 AWG twisted pair from Jameco:

But that's just one option. Using just one of the pairs in a Cat5e or Cat 6 cable also works, as would many other options!

How low can you go?

I have the habit of purposefully not babying my electronics. For instance, I don't bother with ESD protection while I work on my stuff. Why? Because if a device I intend to turn into a product is sensitive to ESD, I'd much rather find out myself, during my prototyping and testing, than have my customers find out after I've sold a bunch of them. I prefer not to create products that turn into a major headache once on the market!

So, when testing the ManT1S, I also have not been picky about what wire I've tested it with. In fact, I've gone out of my way to be nasty to find out what the limits are!

Here is some of the lousy wiring I've used to wire ManT1S boards together:

Starting at the bottom, we have some power cord wire that I cut off from a wall wart. It worked fine! Going clockwise, some cable with two twisted pairs in it that I picked up somewhere a long time ago, followed by a 25 ft spool of very thin phone wire, untwisted. No issues with either one! Next, yes, that's some old speaker wire I had laying around. Followed by the LED floodlight demo that's shown in the campaign video, which came with a waterproofed cable preinstalled, and I put it to use for T1S networking duty. Nobody would claim either of these qualify as "twisted pair", but the T1S communication worked just fine over them! Next: yes, I tried DuPont wires. And last and very much least, I sloppily twisted some hook-up wire of slightly different lengths together to see if I could make it fail. Nope! The ManT1S boards communicated just fine over all these examples of lousy wiring. In fact, I have not yet found wiring that didn't work!

Now of course, if you want to maintain the best signal integrity and bandwidth, while having the mixing segment extend the maximum distance, you might want to stick to some nice twisted pair wiring. But this goes to show just how forgiving T1S networking is. It also opens up some nice use cases for home automation and putting that old doorbell, thermostat or landline phone wiring that's already installed in your house to good use!