This one might be better, there's no bridge except two for connecting large areas of GND signals (I don't know if this is much useful...)
Seb -- Sébastien Lelong http://www.sirloon.net http://sirbot.org 2009/9/10 vasile surducan <[email protected]> > Hi Seb, > > I am appreciating your enthusiasm, however the shield you've designed it > hasn't too much ability of shielding. > > If your need carrying PWM signals from one board to other, where both or > only one board has also analogic areas, you must be very carefull. You need > two layers and ground planes on both layers connected through a number of > vias. > > If your application is pure digital, both boards without any analogic area, > then shielding is not important. > > If the PWM is used for generating a clean analogic signal after a > filter, could be a serious problem (clean PWM filtering with first order > filters is impossible, no matter what you have seen on the enthusiastics > websites; clean means lower than 5mV ripple). > > Learn to avoid in your design 90 degree direction changes in your routes as > a general rule. If you have two layers, use traces equaly on both > layers. Avoid multiple layer changes on clocks, PWMs and other agressing > signals. Designing a PCB it's like programming. You can't do it well if you > don't do it continously...Biggest problems start on 8-12 layers, but two > layers an a PIC it's a good start. > > > On 9/10/09, Sebastien Lelong <[email protected]> wrote: > >> Hi guys, >> >> >> I've committed Jaluino PCB & schematic template for Eagle (see >> http://code.google.com/p/jallib/source/browse/trunk/project/jaluino/schematics/jaluino_shield_template_eagle.zip). >> From this, I tried to create a shield that could act as a layer, an >> intermediate, between Jaluino shields and Arduino shields. The idea is to >> plug this intermediate shield onto Jaluino board, then plug an original >> Arduino shield on top of this. >> >> Attached are pictures of: >> >> - schematic: with mapping between Jaluino & Arduino pins. For PWM >> channels, one is taken from RC2/CCP1, another is taken either from RC1/CCP2 >> or RB3/CCP2. RC1 and RB3 are multiplexed, so you can choose which of these >> two pins will carry PWM. Using this approach, it may increase compatibility >> (still only 2 PWM channels will be available, but for one, you can choose >> where). As for analog pins, RA3/AN3 is mapped with AREF. Other mappings are >> quite explicit. I'm open to suggestions ! >> >> - PCB: the resulting PCB. Green aeras are considered as blue tracks (but >> couldn't make them blue...). Quite a lot of vias, not that beautiful, >> sorry... >> >> >> Finally, I had a hard brainstorming (not just with myself this time), to >> find a name for this shield: "Styx". So this is Jaluino "Styx" shield. Why ? >> Well... Well in Greek Mythology, Styx is the river between Earth and >> Underworld, a clear frontier between two worlds. I hope this illustrates as >> good as possible the main purpose of this shield. Defining which part is >> Earth, which part is Underworld in our case is left to readers' objectivity >> :) >> >> >> http://en.wikipedia.org/wiki/Styx for more... >> >> >> [image: Dor%C3%A9_-_Styx.jpg] >> >> >> >> Cheers, >> Seb >> -- >> Sébastien Lelong >> http://www.sirloon.net >> http://sirbot.org >> >> >> --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/jallib?hl=en -~----------~----~----~----~------~----~------~--~---
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