yosheli123

That tops out at around 300meters. Ours goes beyond 1km. Still there's is awesome for camera feeds; I love the Blue Robotics hardware, SPEBlox Long is just a different application (more industrial automation focussed)

Awesome to have your input on this. I'd love to talk to you in person to learn more. Reach out at josh@botblox.io

Yeah, I think there's other considerations like power, overall size, input voltage supply, ease of maintenance etc.

If it's purely down to cost then I don't these modules would compete

That's brilliant!

Smaller, lower power, more reliable + a somewhat open spec being developed around it (unlike things like homeplug which are kinda murky). Generally it's the same people who developed the ethernet spec that are developing single pair ethernet, so it's designed to play nicely with it.

You'd use some standard tether cable, Blue Robotics sell good stuff for that.

https://bluerobotics.com/store/cables-connectors/cables/fath...

Then just straight onto the screw terminals.

tbh I don't think I'm really ever going to compete with the mass volume stuff on DSL. I think this is more for applications where space is the key motivator, rather than cost.

Yeah I'm really targeting directly embedded applications that will want single pair ethernet. Robot tethers and things like that.

$200 a pair is definitely possible. $100 a pair is probably possible in a year or so, I just can't place orders for the chips in bulk because of the chip shortage so everything is inflated.

Yeah fair. I'm aiming at new space constrained applications with this.

Basically just any CAT5e like twisted pair has worked for me up to 1km. 26AWG unshielded twisted pair basically, 100Ohm diff impedance. Cost of cabling is pennies IMO. Labor cost, who knows.

Optical can be quite expensive though these boards aren't exactly cheap (yet).

Yeah approx $400 for a pair. Mainly chip shortage messiness, I think I can get the cost down to less than $200 a pair in April 2023.

Regarding VSDL, never used it myself; I guess it would come down to space/power considerations. I haven't seen VDSL used much in the industrial automation, single pair ethernet seems to be the preferred choice.

Yep full duplex

So I built a tiny single pair Ethernet bridge (10BASE-T1L) that can transmit 10mbps over a kilometer on a single pair of twisted copper wires.

Would love to get some feedback for the next iteration

One point I completely forgot was Gigabit Home Network, (G.hn) as a alternative to 1000BASE-T1. It essentially does the same thing and can achieve long ranges. Ultimately this technology is designed to pump 1000Mbps down nasty home wiring, so using it on a single pair of wires is probably going to result in a very good range.

The encoding scheme here is OFDM, aka, break the signal down into multiple signals at different frequencies, and send it down the wire.

It's more robust than SPE, but it requires more costly and larger ICs than SPE. When you can define a connector and cable, SPE is still better in terms of cost and size I believe.

G.hn could have its uses in retrofitting older wiring systems.

BTW, since I have the hardware on hand, let me know if y'all want me to conduct specific tests. I have a beauty of an oscilloscope that can get very good sampling resolution on this.

I certainly believe SPE is the future but not as an immediate replacement to ethernet for the following reasons:

- BASE-T1 PHYs and connectors are going to be more expensive than cheapo BASE-T PHYs and RJ-45s for a while.

- The entire industry is based around BASE-T, try finding off-the-shelf mobile imaging hardware (or other embedded sensors) that supports BASE-T1.

- BASE-T technology is less fragile, ultimately a single pair is more susceptible to signal loss / reflections and needs more complex encoding/transmission schemes to overcome this. (For example, 100BASE-T uses 25MHz, two states, four pairs. 100BASE-T1 uses a 33.33MHz, three states on a single pair. This reduces the tolerable noise floor and requires the use of better cabling. 100Mbit ethernet is damn-near indestructible I've found. (There is another alternative here which I will get to in a moment).

Despite these issues, SPE's benefits will win out for mobile applications that have Size and Weight requirements. GigaBit speeds (or even up to 10 gigabit) on a single pair is just too damn tempting and can translate directly into better products. Want an example? Imaging you're making a payload for a drone; you probably use slip rings and your electrical contacts are limited. Using SPE means you can cram more data down the same slip rings, resulting in higher resolution imaging compared to a competitor using standard ethernet.

My understanding is that 10BASE-T1L is designed for long reach applications like factory automation, to connect between clusters of devices using 10BASE-T1S (all sitting on the same pair of wires). 100BASE-T1 and 1000BASE-T1 are for ideally for mobile applications.

Anyway this is all theoretical, it so happens that I run a hardware startup called BotBlox where I design compact ethernet hardware. I've designed a compact 1000BASE-T to 1000BASE-T1 converter, partly as a working prototype to get used to this technology. I believe there needs to be affordable, compact bridging hardware BASE-T and BASE-T1, and I intend to develop it.

My current tests with 1000BASE-T1 is that the range is not near 40m, I managed to get around 10m before it dies. I need to do more testing on this to see whether it's the cabling, and the firmware I made.

I have a 10BASE-T to 10BASE-T1L board in manufacture because I'm ridiculously excited about the prospect of 1.6km copper transmission. We'll see how this goes.

Anyway, there's a link below. The chip shortage has destroyed my ability to scale up on this board, hence the high price. I expect once chip shortages abate, achieving a $100 price point on this kind of board is achievable.

https://www.botblox.io/products/tiny-single-pair-ethernet-co...