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I don't think that's a fair position to take. PCB design is complex - there are very few complex tasks that can be whittled down to a single click of a button w

by Alupis 3y ago

I don't think that's a fair position to take. PCB design is complex - there are very few complex tasks that can be whittled down to a single click of a button with good results. Take software for example - newbies can and do write code, but it's rarely good or error-free. Codeless solutions have appeared - but there's good reasons even those aren't used often. Any auto-routing feature is going to appeal to absolute beginners, and few if anyone else. So, we're asking a FOSS project to spend a tremendous amount of time building in a good-enough auto-routing feature that only a small portion of their audience will ever actually use, or use more than once. If your board is simple enough for auto-routing to provide value to you - then I would assert your board is simple enough for you to spend 30 minutes doing the layout yourself.

deepspace 3y ago
It's been 30 years since I was working closely with PCB designers, but back in the day, the professional CAD folks would absolutely run the autorouter first, and then use that as a starting point to tweak the layout. I would have thought that autorouting would have improved in all that time, but from this conversation, it sounds like it has become worse. What gives?
- syntheticgate 3y ago
  I'd suggest design complexity has scaled at a faster rate than the autorouting tech. In a closer-to-DC world years ago, optimal routing was nice but often not a requirement. In today's high-speed designs, proper routing can be the difference between working and not working, and there is a constant battle of constraints and trade-offs that humans can deal with more effectively. Attempting to constrain a complex design such that an auto-router can be successful can often result in an over-constrained problem which then makes the auto-router unsuccessful. More focus on hybrid routing tools where there is some automation going on while a user routes things is typically were you get much more useful help in modern ECAD.
- dvdkon 3y ago
  Back then, many boards used to be routed with vertical traces on one layer and horizontal traces on another, "Manhattan routing". Somehow, the circuits worked. Nowadays you can't be so "careless" to hit EMI targets or even to get a working board. Switching PSUs, data buses, clock signals, all those have spacing, impedance control, ground coupling and other requirements. Maybe you could encode all of them in the schematic and then let a modern algorithm suggest a board layout, but in practice nobody seems to do it that way (note that I am just a hobbyist with limited experience).
  - RF_Savage 3y ago
    And the eighties computers with low cost two layer boards and complex designs like that on them are one of the reasons why all products have to pass FCC Part 15 radiated emissions EMC tests, not just the intentional radiators. The old computers were rather bad on that front.
ajford 3y ago
Gotta say your comment is either from the point of view of a subject matter expert who's forgotten what it's like for newbies or hobbyists, or someone who's just condescending. PCB design is complex, but the kind of boards a newbie or hobbyist is likely to design using a fresh tool like this wouldn't be. Hell, most signals under a few MHz are quite tolerant of shitty routing and would be just fine. I worked with an RF engineer who'd been in the field since the 70s, and he'd always use the auto-router for anything "slow". If it was "digital dc" or digital logic or under a MHz then it was auto-routed because he didn't have time for that. Anything critical that carried RF or drove a reference was hand-routed first then anything left would get the auto-routing treatment. And this was in a radio astronomy observatory!
- Alupis 3y ago
  I disagree. Learning the tools and skills to do a task is the default assumption for anything - be it riding a bike or building a SaaS. If you cannot commit a few minutes to learn how to route correctly, then you really are just "hoping" for something magical to work. Would you take the same position in software? Almost certainly not - because it is complex. Sure, there's plenty of no-code or low-code platforms out there - but why are they not more popular? Because they universally suck and their target user quickly "graduates" into real coding. People asking/demanding auto-routers are asking a FOSS project to commit a lot of time and resources (because it's not trivial to implement!) to a feature a very small subset of their userbase will ever use, and will also be the most negatively impacted by said tool when it fails them without them realizing. Seriously, if your board layout can be done by an auto-router then it is a trivial board and you should spend a few minutes learning the basics. There is nothing but upside in doing so.
  - carbotaniuman 3y ago
    I think this comment made a lot more sense in a world without ChatGPT and Copilot - the popularity of those things are off the charts!
    - Alupis 3y ago

by Alupis 3y ago

deepspace 3y ago

It's been 30 years since I was working closely with PCB designers, but back in the day, the professional CAD folks would absolutely run the autorouter first, and then use that as a starting point to tweak the layout. I would have thought that autorouting would have improved in all that time, but from this conversation, it sounds like it has become worse. What gives?

syntheticgate 3y ago
I'd suggest design complexity has scaled at a faster rate than the autorouting tech. In a closer-to-DC world years ago, optimal routing was nice but often not a requirement. In today's high-speed designs, proper routing can be the difference between working and not working, and there is a constant battle of constraints and trade-offs that humans can deal with more effectively. Attempting to constrain a complex design such that an auto-router can be successful can often result in an over-constrained problem which then makes the auto-router unsuccessful. More focus on hybrid routing tools where there is some automation going on while a user routes things is typically were you get much more useful help in modern ECAD.
dvdkon 3y ago
Back then, many boards used to be routed with vertical traces on one layer and horizontal traces on another, "Manhattan routing". Somehow, the circuits worked. Nowadays you can't be so "careless" to hit EMI targets or even to get a working board. Switching PSUs, data buses, clock signals, all those have spacing, impedance control, ground coupling and other requirements. Maybe you could encode all of them in the schematic and then let a modern algorithm suggest a board layout, but in practice nobody seems to do it that way (note that I am just a hobbyist with limited experience).
- RF_Savage 3y ago
  And the eighties computers with low cost two layer boards and complex designs like that on them are one of the reasons why all products have to pass FCC Part 15 radiated emissions EMC tests, not just the intentional radiators. The old computers were rather bad on that front.

ajford 3y ago

Gotta say your comment is either from the point of view of a subject matter expert who's forgotten what it's like for newbies or hobbyists, or someone who's just condescending. PCB design is complex, but the kind of boards a newbie or hobbyist is likely to design using a fresh tool like this wouldn't be. Hell, most signals under a few MHz are quite tolerant of shitty routing and would be just fine. I worked with an RF engineer who'd been in the field since the 70s, and he'd always use the auto-router for anything "slow". If it was "digital dc" or digital logic or under a MHz then it was auto-routed because he didn't have time for that. Anything critical that carried RF or drove a reference was hand-routed first then anything left would get the auto-routing treatment. And this was in a radio astronomy observatory!

Alupis 3y ago
I disagree. Learning the tools and skills to do a task is the default assumption for anything - be it riding a bike or building a SaaS. If you cannot commit a few minutes to learn how to route correctly, then you really are just "hoping" for something magical to work. Would you take the same position in software? Almost certainly not - because it is complex. Sure, there's plenty of no-code or low-code platforms out there - but why are they not more popular? Because they universally suck and their target user quickly "graduates" into real coding. People asking/demanding auto-routers are asking a FOSS project to commit a lot of time and resources (because it's not trivial to implement!) to a feature a very small subset of their userbase will ever use, and will also be the most negatively impacted by said tool when it fails them without them realizing. Seriously, if your board layout can be done by an auto-router then it is a trivial board and you should spend a few minutes learning the basics. There is nothing but upside in doing so.
- carbotaniuman 3y ago
  I think this comment made a lot more sense in a world without ChatGPT and Copilot - the popularity of those things are off the charts!
  - Alupis 3y ago