Hackaday Links: Sunday, November 29

Sometimes we wonder if we’re making good choices with PCB layout when using EagleCAD. Watch how the pros do it with a video of an hour-long Adafruit PCB layout session compressed into seven minutes.

[Elijah] documented his RepStrap build. This is a chicken-or-egg project in that RepStrap machines are built without the assistance of an already existing RepRap.

Here’s an ASUS concept from CeBIT this year for a laptop that has two touch screens and no physical keyboard. Isn’t this just the DS project we saw this week but in a nice case?

[James] conjured up a physical realization of the Spinning Wheel of Death for an art exhibit. We can’t stop smiling when looking at this artful hack.

I’m sure nobody will raise an eyebrow when you pop out that roll of duct-tape and affix your phone to the airplane window. That’s what [floe] did to make this airline flight time-lapse video with an Android phone. Aren’t you supposed to turn off all electronics for takeoff?

47 thoughts on “Hackaday Links: Sunday, November 29

  1. That print layout design of adafruit i don’t really call pro.
    90° angles ? , is this like you’re first project ?
    And for some people that are going to complain that 90° doesn’t matter , it does for etching purpose otherwise the result may fail.

  2. I’ve watched firsthand Altium Designer do complex circuit board routing in seconds – but that’s what you expect from $10,000 software ;)

    Me, I’m still on stripboard designing/building for my own little projects, but I do get the lovely job of soldering the circuitboards designed on Altium & etched + silkscreen printed by a machine (gotta love solder resist!)

  3. “Aren’t you supposed to turn off all electronics for takeoff?”

    I think you can turn it on “airplane mode”… so it doesn’t let out any radio-frequency interference… and anyway, it’s outside the plane.

  4. Yep. Don’t really see how the Eagle video is helpful or ‘pro’. I was expecting some hints or tips to make the software perform better, or advice on layout considerations for mixed signals (etc..) not just some guy routing a layout by hand.

    Pretty basic board from the looks of things.. How ’bout a 44 pin TQFP package with limited board space and only two layers? How about information on optimizing the autorouter?

  5. first i wanted to say hi to mike for doing a great job with the site lately, nicely done.

    next up, @max montana – 90 degree bends make absolutely no difference and are perfectly fine for any design where you your traces arent considered ‘impedences’ – many many many years ago, the sharp corners would de-laminate easier, but CAD programs now curve the corners so that’s irrelevant. complaining about 90 degree bends is a myth with no basis, it’s repeated (still) around the web, and is usually promoted by people who don’t know about routing PCBs (yet).

    here’s a PDF about this:

    disclaimer as always, i started hack-a-day i’m senior editor at MAKE and also work with adafruit (ladyada).

  6. Oh man I heard of ASUS having a dual screen ebook reader set to come out and I got really excited. I would love for something like they shown there but one e-ink screen or that setup with an e-ink overlaid on a LCD/LED screen. Throw linux on it and it would be all the motivation I need to build that homemade book scanner I have been putting off.

  7. @janin – because autorouting rarely works, it chooses improper line widths, it doesn’t understand proper ground planes… and even when it does work, it’s wasteful (space, vias) and it’s ugly.

    unless you have $10k package, autorouters do not produce efficient and beautiful boards.

    autorouters do not know what the signals are the way the engineer does, and so designing things like ground planes, separating analog and digital ground lines, keeping clocks short, etc. is only possible by hand routing. if you watch the video you will see that parts are moved and pins are swapped to improve the routing.

    if people want to autoroute, that’s fine – have fun, it makes life easier when you start out i think. but the engineer in the video does not and as far as i know, none of my electrical/CAD engineer friends do it, and none of their friends/coworkers do it either. is anyone willing to say who they work for and what they make that actually uses autoroute? so far no one has when i’ve asked, mostly because no pro seems to use autoroute, ever.

    last up, @medix – this is just one of many videos i know ladyada is working on showing working in eagle, the next complaint will likely be how complicated and “not beginner friendly” it is.

    you cannot please everyone, but if you have a “pro” video i’d love to see it and i’d post it on MAKE so there’s more than one example out there. and you too can have snarky people say “shoulda used autoroute” :)

  8. Kicad was mentioned already…. as an alternative to Eagle

    However, do not forget Geda, gschem and pcb [1]….
    This tools follow the philosophy of unix (one tool per task) and interact via scripts with each other. Learning curve might be greater compared to other softwares. However, it is a bit like LaTeX via MS Word… if you like to have final control over the output … pcb and gschem files are pure ASCII… fire up emacs or vim and hack-a-pcb…

    [1] http://www.gpleda.org/

  9. pt when are you going to make MAKE affordable?
    Also you kind of have a berating, almost dickish tone. Sure, autoroute has some bad points but it is a stepping stone for many. I personally repurpose PCBs these days to try and be greener than the rest of the heathens that have to cut a new board every iteration of their project. Google it sometime.

  10. With regards to the pro layout, there are a couple of pretty pronounced acid traps in the above screencap alone, so I’m guessing there are quite a few more in the design. Lots of off-angle pad entries, which may or may not pass DFM muster in your shop. Are the footprints IPC-compliant? Just eyeballing it, some of the annulars looked scant but it’s really hard to say. Are the planes balanced, or is there provision for thieving? Do the component locations pass manufacturability requirements for shadowing and part placement? I don’t see any automated DRC or DFM being performed. Hopefully it’s been done outside the scope of this video, as those would be integral to any professional layout process.

  11. @PT

    The 90° angles is still wrong , i never implied that the signals won’t pass through that .
    I said that it is because of the etching process wich tends to fail at 90° angles .

    That is why new CAD programs curve these 90° angles so that it will work.

    So if you make 90° angles in other programs you can get problems.

    also the pdf link you provided is about CAD design but nowhere in the pdf is written about angles in CAD design , therefore the pdf is irrelevent to this discussion.

    When i have the time i will make a tutorial for better autorouter settings in eagle.

  12. 90° angles have a tendency to emit better than 45° ones.
    It’s not a huge concern for outside equipments, but it can mess with close environment if you play with high frequencies.

    Check for EMC design rules, it’s quite interesting.


  13. @Gene Flintstone

    Dickish tone? I thought that had become the standard for HaD-comments nowadays.

    Seriously. When did HaD come to be this “playground” of experienced and, let’s be honest, cocky engineers?
    (Hint: You sound less like a douche if you _suggest_ improvements in projects, instead of blatantly pointing them out, and mocking the author of their amateur-ness.)

    Wasn’t HaD always meant to be for the individuals who wanted to hack? The ones not caring about design rules, manufacturability-rules and aesthetics of the overall design? The whole point in a hack is that, as long as it works, everything else isn’t of a concern.
    (Though, the more beautiful a hack is, the more “geek-cred” the author will receive. Up to a point when the hack isn’t a hack anymore.)

    The conclusion of my rant: Please shut your pie-holes, everyone, if you can’t phrase something _constructive_.

    Cheers, and keep up the good hacking-spirit.
    -Michael L.

  14. @Michael L.

    While I agree with your ‘suggestion’ rather than ‘pointing out’ argument, I think the ‘cocky’ engineers have a point here. If something is advertised as ‘Watch how the pros do it..’, well, you would expect ‘pro’ stuff, and frankly, there is nothing ‘pro’ about the routing job.

    Just because someone pushes out loads of boards/projects, that does not make them a pro. I have nothing against Ladyada, and I admire what she does but her PCB layouts are not that great.


    On the subject of autorouters, I’d like to see your electrical/CAD engineer friends route differential signals manually. Seriously.

  15. [pointing out]
    I’m pretty sure the colours don’t spin in the ‘wheel of death’.. just the highlight.

    Fabricate a clear mold to fit around the ‘wheel of death’ that has the semi-transparent, black fan gently painted on it, and spin that.

    First comment btw and I love this site :)

  16. @pt: “because autorouting rarely works, it chooses improper line widths, it doesn’t understand proper ground planes… and even when it does work, it’s wasteful (space, vias) and it’s ugly.”

    Define ‘rarely works’. Eagle is pretty good in terms of usability, and with a little reading, you’ll find that the software provides a means to specify net widths for auto routing, making the routing of power traces and signals quite efficient. Also, if you take the time to *look* at the autorouter, it has optimizations to cut down on the number of vias. Space usage is often determined by the layout of the parts specified by the user.

    It may not be ‘totally’ free, but I’ve rather grown to like it. It’s a good interface for the price (free for two layer) and the results are quite good.

    And again, nothing ‘wrong’ with the video – just show me something ‘pro’ if that’s what you’re going to call it, yeah?

  17. I had that dual-screen idea a long time ago! Where’s my royalties?

    Although, my idea was just touch for the lower panel which would be reconfigurable as QWERTY/DVORAK etc. keyboard, touch mouse, drawing tablet, drag-n-drop customizable panel, etc. Hey man, I never said I BUILT the thing.

  18. @Gene Flintstone – MAKE is affordable – in fact no one has complained about the price, they usually say we should raise the price for print. the digital edition is $10, that’s really cheap. Digital Edition Only – 4 Volumes + 1 Bonus Issue: US $9.99 you can even print that out.

    you can read it online for free if you look around (digital edition, free PDFs) it’s less than $24 a year if you look for a discount deal and lastly if you still have problems with that MAKE does give away volumes to schools, makers and folks who can’t afford. usually when someone says this they’re just being snarky, and the rest of your comment just proves that. you don’t have a problem with the price of MAKE you just don’t like what i said it seems.

    as far as autorouting and your comment about my comment goes, read what i said, again.

    if people want to autoroute, that’s fine – have fun, it makes life easier when you start out i think. but the engineer in the video does not and as far as i know, none of my electrical/CAD engineer friends do it, and none of their friends/coworkers do it either. is anyone willing to say who they work for and what they make that actually uses autoroute? so far no one has when i’ve asked, mostly because no pro seems to use autoroute, ever.

    if you check back here you notice not a single person who does engineering for a living will say that they use autorouting, what they work on, or where they work.

    comments online always sounds negative, i try really hard to add smileys, information and value – the HaD comments are mostly “pooping” on anything anyone posts.

    keep in the mind this video is not a “pro” example, the author of HaD said this. the video was meant for beginners to see how handrouting is done, don’t get hung up what the HaD authors says, adafruit is known for beginner tutorials and i’m sure you know that.

  19. @medix – you asked “Define ‘rarely works’.” i’ll do even better, post your questions on adafruit on the actual post with the video. you can hear from ladyada yourself and i’m willing to bet that once you do, you’ll agree.

    you also said “just show me something ‘pro’ if that’s what you’re going to call it, yeah?”…

    who called it pro? again, it’s video to show beginners what hand routing is. the HaD author called it pro, don’t get hung up on what someone else said, go visit the post :)

    @Hamza – please show your PCB designs or point to a commercial design that’s in the market that you made :)

  20. pt all awesome points! My issues of Future Music from over the pond are cheaper and come with software. I don’t do the ebook thing. Never been all that useful to me. So I guess I’m left with forget it. Easy enough.

    I understand your point about tone thru text. It is hard to see what someone is really thinking without our usual visual cues sometimes. It just looked a lot like you were laying the smack down for someone insulting your colleague’s board layout after declaring this is your world. And if so then maybe I’m in the wrong place.

    As for the pro end of autoroute, my uncle worked with it for 5 years at his fabrication job at a mom n pop specialization shop making various sundry boards for special duck cameras and tidal recorders for the DNR and enough other things for other people that he bought a lake house. He later got a little tired of deadlines and switched to cleaning up toxic waste sites. As for schematics and documentation and such that you request bwahahaha I am not bothering that man with it for an internet debate.
    Best of luck Kaleb and HaD it was fun.
    end transmission

  21. @PT, I think what you’re seeing is a reaction by professionals against dilution of the term. Does that make us cocky? Probably in some eyes, but in my mind it’s justified. Plainly put, that layout promotes practices which, in some circles, would be viewed as ill-advised, and yes, unprofessional. Were this not the case, there would be no reaction. Now, I don’t view it as an affront to the industry…that board will work, and I’m sure it will be perfectly manufacturable in the quantities that Ms. Fried intends. The video seems to address the needs of its intended audience well, and I find that commendable. I think the only point of contention, then, is its characterization by the submitter as a “pro”-quality design, which it is not.

  22. @Gene Flintstone – thanks :)

    @wrr – agreed, HaD said pro, the video is not meant to show off it’s meant to help understand what hand routing looks like.

    that said, if you ask any professional who does engineering for a living the only thing they’ll say that is “ill-advised” is using autorouting in eagle at their workplace on shipping boards. i’ve talked to engineers around the world about this at top orgs and they all agreed, if you can provide specific examples to the contrary i’d love to talk to them, i was surprised to hear this too.

  23. Pt is correct. Nobody in the industry would even consider using eagle’s autorouter for anything which can be routed by hand.

    Try this experiment:

    Next time you design a board in eagle take some time and carefully route it by hand. save a copy of the board, rip it up, and try to create a comparable board using the autorouter. No matter how much tweaking you do you won’t be able to create a comparable layout.

    I’ve done this with some of my boards and I couldn’t even fit all of the traces in the same dimensions when I autorouted.

  24. @pt

    First fo all, I am not defending autorouters, I am simply pointing out that there are certain things you would _need_ an autorouter to accomplish, like impedance matched signals etc. Your comment about none of your engineer friends using an autorouter might be true, if they haven’t designed any high speed boards, very unlikely if they have though.

    Perhaps they don’t use autorouters for general signal/power routing and good on them for doing so! (I don’t use autorouters for that purpose neither)

    I don’t have much experience with the Eagle autorouter myself so I can’t really comment on how bad it is, going by the general quality of the software I would take a wild guess and call it useless, but software I use (OrCad Layout/PCB Editor and Altium Designer mainly these days, if you must know) does a decent job of routing even general signals once you set up the autorouter properly (spacing, keep-out areas, etc. Just pressing ‘Autoroute’ is not the way to do it!)

    Simply calling all autorouters useless is wrong, that’s what I am trying to say. Is it elegant to auto-route everything? Hell no, I never said that.

    And no, I won’t show you any of my designs because I know what I talk about is true and I don’t feel the need to prove it to you :)

  25. @Hamza – you wrote… “I won’t show you any of my designs because I know what I talk about is true and I don’t feel the need to prove it to you”.

    and that’s that, you’ll snark on someone else but won’t show anything you’ve done. typical :)

    as far as calling autorouting “useless” i never said that, you’re trying to make it sound like i said something i did not. search this giant thread – you won’t see useless from me, in fact i said “if people want to autoroute, that’s fine – have fun, it makes life easier when you start out i think”.

    @eric – thanks for chiming in, very appreciated and your example/experiment is great.

  26. @pt

    Again, I don’t feel the need to prove anything to you. If you must know though, I do work with FPGAs and high speed interfaces/memories on a daily basis so I know what I am talking about :)

    In my original comment my intention was not ‘snarking’ or whatever, I just thought your comment on how your engineer friends did not use autorouters _at all_ was funny, nothing more nothing less. You wanted to hear more of my ramblings by asking me to post one of my designs, so I did explain my reasoning for the initial comment.

    Apologies on the second bit though, you never went as far as to call the autorouters useless and I missed that, my bad.

    Anyway, I think I’ve said what I wanted to say and I don’t want to get into a comment war so I will leave now…

  27. @Hazma I’m not taking sides here, but I know that pt is usually fairly willing to admit when he’s proven wrong.

    The problem is that at this point all we have on your side of this is a “because I say so” from someone we don’t know anything about.

    Unfortunately, it’s a very common practice for people to act like they know a lot more than they actually do online, even to the point of faking credentials.

    A simple example would go a LONG way on improving your credibility. If you can show that the autorouting can work well I’m fairly certain you would have a hundred converts asking you for tips/advice. A 2 minute video showing an autorouter running on a simple layout would be enough.

    #^!!, ada probably posted the cad file from the above video, just pull the traces out and autoroute part of it for an example.

    I’ve heard a lot of people say a lot of bad things about autorouting boards, and honestly you’re only the third or fourth person that i’ve seen argue the opposite point.

    Honestly, if there’s a way to make autoroute work well, or situations where it’s nearly required, I would love to know about it.

    After all, the biggest challenge to learning is figuring out what you don’t know.

    I can see how your point about high speed signal lines is valid, it’s a pita to route things like 16 line adc traces but I’ve yet to see an autorouter that didn’t need at least another 30hrs of manual routing before the crosstalk drops to negligible amounts.

    Seriously, there are hundreds of people watching this thread to try and learn something new. (or at least get a glimpse of what’s possible)

    If you know something that we don’t, Please, Share!

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