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fantastic video of ladyada routing

eur

Hi

 

I'm surprised no one posted this:

 

http://www.adafruit.com/blog/2009/11/19/pcb-routing-with-eagle-video/

 

(via Make)

 

Ladyada is an accomplished PCB publisher. From what I can see, this is

a daughterboard for an SD card, with an SMD card connector and a

voltage level shifter.

 

It is fascinating to watch her work. As most experienced Eagle experts

know, routing is the Real Work, and the autorouter is for sissies, just

like vias are. After all the work is done, she has only three.

 

See how she wriggles the lines through, sometimes changing the layer of

some signals up to four times. She does not hide the GND airwires and

changes the shape (and layer!) of the GND plane several times. I always

do the GND plane dead last and hide behind via's to patch the different

planes together.

 

She doesn't avoid "acid-traps" (90º angles in traces) either, although

she has set the 45º angle in routing.

 

She does go back to the schematic, but mostly for naming signals, and

gateswapping. I often leave signals unconnected, only to attach them to

the most convenient PIC pin after routing the wires.

 

No movement of components either, and a very neat schematic. My

schematics are a mess, since they are optimised for routing, so all

chip symbols have their pins at the proper sequence.

 

Note the attention to detail when she makes the silkscreen: this is a

board that will primarily be used by others, so she adds lots of signal

names.

 

 

A must-see for everyone here.

 

 

--

Eur van Andel  eur@fiwihex.nl

 

 

Parents

  • She did an Ok job on the layout. Sure she used few vias, but here I have

    the same opinion as Olin: who cares? I really don't like how the traces

    "wiggled" around everywhere, and though this was partly because of the

    large number of through-hole parts, it would have been less necessary if

    vias were used more. Many experienced engineers I know prefer that

    where-ever possible, with 2-layer boards, you use one layer for vertical

    and the other for horizontal traces. I admit this is harder to do when

    using lots of through-hole parts... which is why I avoid using many of them.

     

    I also find it's easier to ignore the supplys until the routing is done

    for most of the board. Then I like to use one side for a gnd plane, and

    the other side for a vcc plane, and I usually get good coverage with

    both planes, and then optimize traces to decrease the chop-up of the

    supply layers. In the end, even with complicated boards, this greatly

    helps ease routing.

     

    She didn't move parts much (I noticed twice and only watched the start

    and end of the video), but that was because of good positioning before

    she began the routing, which is essential for a good design.

     

    I did like her schematic. I do much the same there, though I don't

    optimize the symbols for "flow" as I find it annoying when doing the

    layout and especially when troubleshooting and when programming if

    there's a mcu. Instead I use named nets and carefully placed parts in

    the schematic to make it both neat and readable.

     

    My 2cents...

     

Reply

  • She did an Ok job on the layout. Sure she used few vias, but here I have

    the same opinion as Olin: who cares? I really don't like how the traces

    "wiggled" around everywhere, and though this was partly because of the

    large number of through-hole parts, it would have been less necessary if

    vias were used more. Many experienced engineers I know prefer that

    where-ever possible, with 2-layer boards, you use one layer for vertical

    and the other for horizontal traces. I admit this is harder to do when

    using lots of through-hole parts... which is why I avoid using many of them.

     

    I also find it's easier to ignore the supplys until the routing is done

    for most of the board. Then I like to use one side for a gnd plane, and

    the other side for a vcc plane, and I usually get good coverage with

    both planes, and then optimize traces to decrease the chop-up of the

    supply layers. In the end, even with complicated boards, this greatly

    helps ease routing.

     

    She didn't move parts much (I noticed twice and only watched the start

    and end of the video), but that was because of good positioning before

    she began the routing, which is essential for a good design.

     

    I did like her schematic. I do much the same there, though I don't

    optimize the symbols for "flow" as I find it annoying when doing the

    layout and especially when troubleshooting and when programming if

    there's a mcu. Instead I use named nets and carefully placed parts in

    the schematic to make it both neat and readable.

     

    My 2cents...

     

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