Because, Arduino like many others is a poor design. You have noticed well, an orphan is asking for trouble. As the long routes (where any cm of route means 0.5 to 0.7 pF parasitical capacitor) on the OSC pins with discontinuities like jumpers. Vasile
On Thu, Aug 5, 2010 at 11:48 AM, funlw65 <[email protected]> wrote: > No, it's ok, I saw also original Arduino design have orphans... > > Vasi(funlw65) > > On Aug 5, 6:03 pm, Sebastien Lelong <[email protected]> > wrote: > > Hi Vasi, > > > > 2010/8/5 funlw65 <[email protected]> > > > > > Hi Sebastien, > > > > > Good job, I like it very much. Is a nice addition to an Arduino board. > > > You tried to see how it looks if you remove those orphan islands from > > > the copper pour? > > > > What do you mean with these orphan islands ? Some copper is automatically > > added by Eagle with Ratsness feature, this can explain those little piece > of > > copper. I may need to adjust ratsness parameters to remove them if this > is a > > problem. > > > > Cheers, > > Seb > > > > > > > > > > > > > Vasi(funlw65) > > > > > On Aug 5, 3:56 pm, Sebastien Lelong <[email protected]> > > > wrote: > > > > Hi guys, > > > > > > I tried to design Cuckoo PCB, attached are Eagle files and screenshot > for > > > > bottom and top layers. Most traces are 16mil width, sometime 14mil to > > > pass > > > > between holes, and 5V/GND traces are 20mil. > > > > > > This is a double-sided PCB, aimed to be plugged upside down: bottom > side, > > > > where Cuckoo drawing is visible, is the one that can be viewed when > > > plugged > > > > on Arduino. PIC, and most components will be hidden by the board. In > my > > > > "reckoning" is correct, components should fit appropriately between > > > Atmega > > > > chipset, Xtal, push button and shield connectors. Maybe... > > > > > > Subsidiary question: in Eagle, I manually route traces, and added > > > ratsness > > > > rectangle. I wanted to check if no unrouted traces were remaining (I > know > > > > there weren't but...), and Eagle started to create new signals, with > very > > > > little traces and vias. There weren't connected to any existing > signals, > > > > it's as though it was to "cut" ratsness rectangle. I've removed them. > > > Does > > > > anyone know what's the purpose of such added traces/signals ? > > > > > > As reply to you, Sir Vasile Surducan: > > > > > > 2010/7/24 vasile surducan <[email protected]> > > > > > > > We had a looong discussion about ICSP some time ago, so this is the > > > last > > > > > time I'm opening again my mouth (by writting) about this subject. > > > > > Put a 47nF... 100nF capacitor in parallel with your reset switch, > in > > > that > > > > > way when turn ON the power supply, reset will be automatically, > change > > > R1 > > > > > from 1k2 to 10k...33k and take out that diode. > > > > > See for reference (only if consider those above) this one: > > > > > > http://4.bp.blogspot.com/_0iJadzFlwNo/S_OgtycPtxI/AAAAAAAAAAc/vNesIW3. > > > .. > > > > > > Due to lack of space, I've removed reset switch. About reset > resistor, > > > > Arduino already has one, 10K, connected from RESET /MCLR to +5V. If I > had > > > > added another resistor on Cuckoo board, both resistors would have > been in > > > > parallel, resulting in a "not so good value I guess". So, I've made > > > cuckoo > > > > reset resistor optional (for standalone usage, not connected to > Arduino), > > > > and let MCLR connected to Arduino reset circuitry (that is 10K). > > > > > > Diode was removed. > > > > > > > < > > >http://4.bp.blogspot.com/_0iJadzFlwNo/S_OgtycPtxI/AAAAAAAAAAc/vNesIW3.. > > > .>Switching > > > > > the clock through a switch is a very bad idea. Very long routes of > > > clock > > > > > (incuding connectors in their path) is also a bad idea. > > > > > > Connecting to Arduino Xtal is now optional. By default, internal > clock > > > will > > > > be recommanded (16MHz, same MIPS in the end). > > > > > > > If you want to start a merchantable new arduino, imagine the puzzle > > > game > > > > > (on a surface and not a startrek spatial puzzle) and imagine a > complete > > > > > jalluino-picolino (including "shields" ) in that way. Picolino = > very > > > small > > > > > > Sure, how do we proceed ? > > > > > > I think I'll try to build it with some cardboard, to check if all > > > components > > > > fit well. Then I plan to order PCBs from Seeedstudio prototyping > > > service... > > > > > > Cheers, > > > > Seb > > > > > > cuckoo_pcb_top.png > > > > 360KViewDownload > > > > > > cuckoo_pcb_bottom.png > > > > 367KViewDownload > > > > > > cuckoo.sch > > > > 228KViewDownload > > > > > > cuckoo.brd > > > > 66KViewDownload > > > > > > cuckoo_sch.png > > > > 28KViewDownload > > > > > -- > > > 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]<jallib%[email protected]> > <jallib%[email protected]<jallib%[email protected]> > > > > > . > > > For more options, visit this group at > > >http://groups.google.com/group/jallib?hl=en. > > > > -- > > Sébastien Lelonghttp://www.sirloon.nethttp://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]<jallib%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/jallib?hl=en. > > -- 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.
