Recently been focused on single layer autorouting. Despite what Big Routing wants you to think, single layer routing is harder than multi-layer routing. The solution space is smaller and the topology is critical

we must fight the big routings together

i don't think the reason to go multi layer was ever about ease of routing... more so that it allows more denser boards, better SI/PI, and EMC. but this is cool

Sure my point is moreso that a lot of autorouters won’t touch anything less than a 4 layer board. It’s not because they handle more complexity, it’s because they need the massive solution space and have 💩 topologies

This is exactly what i've been trying to tell my inlaws but they don't FUCKING LISTEN

May I ask what algorithms you use, or is that secret sauce?

It’s open source and MIT licensed! The algorithm is more like a pipeline of algorithms where we construct a topology, and incrementally solve planning problems, you can read some high level ideas here:

Thanks!

What's the reason for the traces to be so wiggly at the end of the video?

Improving trace-to-trace and trace-to-pad margins. It is overdone intentionally for this particular board because we’re fabricating it with a laser and I like simpler thermal mgmt, but eventually you can use this spacing for serpentining and power trace width expansion

I used to just do single and double layer and never bothered with the autorouter (or placer) as it just produced garbage, especially with my design rules, such as not running tracks between pins. I don't know if they improved since Protel98 though.

They still kinda suck so we’re building a new one

Heh, I thought I was on shakey ground relying on my experience of one that was 27 years old, maybe not then! ;-)

So true, single-layer PCB autorouting in 45 seconds? That's not a demo—that's witchcraft. Traditional routers see one layer and run screaming; Autorouting just yeets perfect traces like "hold my vias." Open-source flex harder than copper cladding. 🧙‍♂️

What kind of router is it and what is the underlying structure? It looks almost as topological rubber band routing, but not tightly wrapped around the pads. The difficult part in routing is finding the wiring topology. From there, the conversion to actual paths is polynomial.

This gets a follow. I just took a look at the interactive demo and realized that in the not too distant future, all nouns in every world language will be LCSC part numbers.

Newbie question. 3rd pin bottom right… why not a more direct line? Yes there’s lots of room to go between the two other pads, but.. why? Also shocked that today’s CPUs can’t handle “difficult” routing on few-layer boards!

I think it’s just a missed optimization, we focus more on completability vs optimized paths (for now)

Haven't used auto routers for more than 20 years but the bit I just saw wants me not to use them for the next 20 years 😅

i’m sure anyone that has ever played this game intuitively knows this

I think the design is cool. This could be useful for prototyping. But for prod a multi layer board and (multi layer routing) would be great.

Single layer routing without moving parts around is just an exercise in frustration. It will almost never have a solution in the real world. Either allow jumpers or just switch to 2-4 layer routing. Single layer is just not THAT important.

That's actually true

Does it allow you to incorporate these into the routing strategy?

Yeah of course, who would ever say multi-layer routing is harder than single-layer? Man, this Xilinx SoC is pretty hard to pin out, maybe we should go to single layer to make it quite a bit easier

Single side routing is more difficult than multi-layer?? I'm shocked.

Most of the work in auto-routing is developing good heuristics that prioritize the most efficient solutions to a routing problem as early as possible. In the end thought A* what you end up doing, and the search space is ridiculously large, even for small numbers of nodes.

another benefit is it works natively in Flatland

It's easier to draw though!

Well known but I’m curious why you didn’t limit your angles to 45 degree increments.

It’s so beautiful.