Hi Vasile, I've committed my last try, including aeras with GND signals, propagated over the board (I've finally managed to use polygons with rastness option).
> Unconected shield areas acts as antennas for the adjacent signals near the > area. > I think the GND should be also connected to some connectos. > GND is currently connected to 3 pins, 2 pins adjacent, and 1 on another connector. I can't decide where to put GND on pins, this is imposed by either Jaluino pins or Arduino pins. > For a goos shield design at home, use a double layer PCB, design routes on > one layer and keep the other layer as ground isolating the component pins > with a large drill in the copper (ie, a 0.8 drill diameter, 1.5 or 2mm > diameter for copper isolation). This tehnique is used to produce high > quality RF PCB's at home. > Connect with more vias (at least 10-20 for DC or PICmicro design and up to > thousens for RF - not suitable for home) between the ground planes of the > layers. > Try to go smaller as possible with your PCB designs, keeping an easy way to > replace any components. This is the right way for increasing PCB design > performance. > > I can't produce a double layer PCB at home... More, as I said, these shields aren't RF shields, but "just" daughter boards. In any case, I clearly won't fell confortable when it come the time to design advanced high quality RF PCBs... :) I'll try to build the current one, as a Proof Of Concept. It'll mainly be used to plug prototype board, like this one: http://www.ladyada.net/images/pshield/miniproto.jpg . As for other more advanced Arduino shield, we'll have to check... or design our own. Cheers, Seb -- Sébastien Lelong http://www.sirloon.net http://sirbot.org > > On 9/10/09, Sebastien Lelong <[email protected]> wrote: >> >> 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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