Hi Richard, Hope your holidays were nice ! (they usually are...)
> I noticed this topic and if you want I can help you with creating a > nice main board. Great, good to hear ! > > Maybe it’s an idea to make a nice double sided main board with a > 18f4550 with all furthers > And extension possibility’s instead of a small single sided one which > will have its limitations > Of course people must buy this board but shall cost not more than > approx. €15 to €20 > all extension board we can try to design as single side so home made > versions. Having a double sided main board would be great, but it may be too early for now. I think we should first experiment what's a good board is, the place of shield connectors, and mostly how people would want to actually buy a professional looking board. Because 18F4550 gives a too complex PCB layout for a single sised board, I've focused on a smaller version using 18F2550. I've posted few things on jalliblog, included my last schematic & PCB: http://jallib.blogspot.com/search/label/jaluino Do you any weird things ? I've not tested it yet, but it's Work In Progress... Cheers, Seb -- Sébastien Lelong http://www.sirloon.net http://sirbot.org > > > > > On Jul 26, 11:43 am, Sebastien Lelong <[email protected]> > wrote: > > Hi, > > > > Here's a new schematic for Jaluino Medium board:18F4550 is replaced by > > smaller 18F2550, so the PCB layout is expected to be easier, helping > focus > > on schematic rather than layout issues. I've recently received a couple > of > > them, so I'll be able to prototype few things. > > > > I tried to include Albert's suggestions, hoping it's correct now... Power > > supply can be from USB or external, selected using a jumper. > > > > Any comments ? > > > > Cheers, > > Seb > > > > 2009/7/26 Sebastien Lelong <[email protected]> > > > > > > > > > > > > > Hi Albert, > > > > > And many thanks for this ! For now, I think I'll go with solution B, > which > > > is the one I understand the most... > > > > > Seb > > > > > 2009/7/25 a.faber <[email protected]> > > > > > Hi Seb, > > >> Attached 4 possible solutions > > > > >> Solution A: Almost the current solution, except added a bypass diode > > >> across > > >> the 7805, so it won't blow up if there is USB 5V and not external 9v > > >> Solution B: Current solution, except make power selection via a jumper > > >> selection (less user friendly, no voltage drop) > > >> Solution C: Auto power selection via 2 schottky diodes (drawback, > voltage > > >> drop of ~0.3v) > > >> Soltionn D: Auto power selection with self power dominance (drawback, > > >> voltage drop of ~0.3v) > > > > >> General remarks: > > >> D6, D7, D10, D11 in my schematic does not have to be a schottky type > if > > >> the > > >> external supply is > ~8V > > >> L1,L2,L3,L4 (ferrite bead, or power choke), not realy required, but > > >> recommended > > > > >> Albert > > > > >> ----- Original Message ----- > > >> From: "Sebastien Lelong" <[email protected]> > > >> To: <[email protected]> > > >> Sent: Saturday, July 25, 2009 12:42 PM > > >> Subject: [jallib] Re: jaluino (first schematic... Richard ?) > > > > >> Hi Albert, > > > > >> I tried to do some research, but I'm lost, this is far beyond my > > >> understanding and I can't figure out how to deal with self-power > USB... I > > >> need your help, would you mind giving me an example of self-powered > USB > > >> vs. > > >> not self-power USB ? Your 18F14K50 PIC is self-power isn't ? I can't > see > > >> the > > >> difference with my schematic... > > > > >> Also, I've found something about using a shottky diode to select +5V > from > > >> regulator or +5V from USB (see picture, part of schematic from an > Arduino > > >> board). Is that what you were talking about ? > > > > >> Cheers, > > >> Seb > > > > >> 2009/7/23 [email protected] <[email protected]> > > > > >> > Hi Seb, > > >> > Some comments on the schematic: > > > > >> > In the current schematic the 5V and USB-5V are connected, this is > not > > >> > according to spec, > > >> > see also the datasheet about USB self-powering. Either way, use a > > >> > jumper selection for the > > >> > power supply or use some shottky diodes, in addition it might be > wise > > >> > to place a by-pass diode > > >> > across the 7805, since these devices don't like to be reversed > > >> > powered. > > > > >> > Why R1? I think you can remove it, since the reset pin is held high > > >> > via R5/D2 > > > > >> > Be sure to put a 100n bypass close to VSS/VDD pins of the PIC, I > don't > > >> > know if C2 is the PIC bypass cap, if so I would > > >> > draw it closely to the PIC VSS/VDD pins > > > > >> > BTW, the 18f14k50 board is working fine > > > > >> > Albert > > > > >> > On Jul 22, 9:37 pm, Sebastien Lelong <[email protected]> > > >> > wrote: > > >> > > Some more thoughts about Jaluino (next guy who talk about math > lib, > > >> can > > >> > you > > >> > > modify the subject plz ?)... > > > > >> > > The connector's layout is very important, as all shields will have > to > > >> be > > >> > > compatible, and will reproduce this layout. > > >> > > For instance, Arduino diecimila has 4 connectors: > > > > >> > > - 2 on on this upper side > > >> > > - 2 on the bottom side, 1 being reserved to power > > > > >> > > Arduino mega uses a much bigger AVR than Diecimila. They put a > double > > >> > > row > > >> > > connector, on the right side. Still, the four previous connectors > are > > >> on > > >> > the > > >> > > same place. As a consequence, shield for Diecimila can be used > with > > >> > > Mega. > > > > >> > > I'd like to reproduce the same. If we build first Jaluino board, > > >> > > 18F2550, > > >> > it > > >> > > could have the same connectors as in Arduino (2 on upper side, 2 > on > > >> > bottom > > >> > > side). Next step is a 18F4550 based board. We could add a single > row > > >> > > connector on the right. In the future, if we decide an even bigger > > >> PIC, > > >> > > we'll be able to double this left connector. > > > > >> > > That said, I still can't produce a PCB, I'm having a lot of > trouble > > >> > placing > > >> > > parts to avoid vias... Any PCB guru here ? > > > > >> > > PS: as a bonus (...) here's my last schematic, with connectors. > > > > >> > > Cheers, > > >> > > Seb > > > > >> > > 2009/7/21 Sebastien Lelong <[email protected]> > > > > >> > > > First try to get a PCB layout gives way too much vias. This is > where > > >> I > > >> > > > spend days to get a decent PCB... > > > > >> > > > Seb > > > > >> > > > 2009/7/21 funlw65 <[email protected]>: > > > > >> > > > > On Jul 21, 7:49 pm, Sebastien Lelong < > [email protected]> > > >> > > > > wrote: > > >> > > > >> I think this assumes the peripheral on the other side (eg. a > PC) > > >> > > > understands > > >> > > > >> RS232 level between 0 and 5V, instead of -12V and +12V. It's > > >> > sometime > > >> > > > the > > >> > > > >> case, and to be sure, using a MAX232 chip is better. That > said, > > >> > > > >> with > > >> > the > > >> > > > >> "plug your own serial module" option, you can choose whatever > you > > >> > want. > > >> > > > This > > >> > > > >> gives a fourth option, a the cheap side, so we new have: > > > > >> > > > >> - FTDI chip based USB-to-serial adaptor > > >> > > > >> - 18F14K50 based USB-to-serial adaptor > > >> > > > >> - MAX232 based, with DB9 connector > > >> > > > >> - resistor based, with DB9 connector > > >> > > > >> - (and last option: "my own way to deal with serial") > > > > >> > > > > Ok, not on board, but I thought they can be disabled by > jumpers, > > >> and > > >> > > > > can be a fast solution to test the software but yes, is not a > good > > >> > > > > ideea. > > > > >> > > > >> Some more thoughts about the board. Original Arduino > Diecimila > > >> uses > > >> > a > > >> > > > >> Atmega168, a 28-pins chip. > > >> > > > >> See:http://arduino.cc/en/Main/ArduinoBoardDiecimila. From > this, > > >> 20 > > >> > pins > > >> > > > >> are "exported" through connectors on sides, where 2 pin are > > >> > dedicated to > > >> > > > >> RX/TX, thus involved in board's functionality (I mean there > > >> aren't > > >> > > > >> completely free, as they are involved in serial). > > > > >> > > > > I don't know, maybe others have more ideas. First, I looked at > > >> > > > > ATmega168 pins, to see some similarities at ports level but I > > >> think > > >> > > > > the key is at software level. And is the only level where > Pinguino > > >> > > > > offers Arduino compatibility (and maybe the reason why the > author > > >> > > > > didn't offered a shielded variant). > > >> > > > > For "reusing" Arduino shields, I think a study must be done. > > >> > > > > Studying > > >> > > > > different shields with their software to see how interact with > the > > >> > > > > board. In what manner are used digital pins, etc. ... Because > I > > >> > > > > don't > > >> > > > > think they take in account very much the particularities of > the > > >> chip > > >> > > > > himself (I think the software is hiding the hardware). > > >> > > > > Maybe is too much work but a shielded board is a must, even if > not > > >> > > > > Arduino compatible. This is jallib team decision, and I hope a > > >> good > > >> > > > > board will increase the number of programmers using jal > language > > >> > > > > (unfortunately, the fact that jal don't have a math library is > > >> > another > > >> > > > > obstacle regarding to "mass" adoption - the new comers remain > > >> with > > >> > > > > basic languages and advanced people go to C language). > > > > >> > > > -- > > >> > > > Sbastien Lelong > > >> > > >http://www.sirloon.net > > >> > > >http://sirbot.org > > > > >> > > -- > > >> > > Sbastien Lelonghttp://www.sirloon.nethttp://sirbot.org > > > > >> > > jaluino_sch2.png > > >> > > 56KViewDownload- Hide quoted text - > > > > >> > > - Show quoted text - > > > > >> -- > > >> Sbastien Lelong > > >>http://www.sirloon.net > > >>http://sirbot.org > > > > > -- > > > Sébastien Lelong > > > > >http://www.sirloon.net > > >http://sirbot.org > > > > -- > > Sébastien Lelonghttp://www.sirloon.nethttp://sirbot.org > > > > jaluino_sch3.png > > 51KViewDownload- Hide quoted text - > > > > - Show quoted text - > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "jallib" group. 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