I need this small board for medium projects (mainly for windmill/solar panel and weather station controllers). I intend to use a 4550 for a USB CNC Router (even if I don't know how to do it yet) but I don't see it as a general board, is too complex to be made at home (not a pretty one).
On Aug 6, 5:55 pm, Joep Suijs <[email protected]> wrote: > Hi, > > Mabe a bit late, but why don't you take 40pin chip? > I once used an arduino but ran out of pins before the end of my > project. And earlier this week, a friend brought a arduinomega - > atmege1280 processor with plenty of flash, ram and pins. Great! (too > bad he took it back with him...) > > Joep > > 2009/8/6 Sebastien Lelong <[email protected]>: > > > Interesting but there's no schematic... Also, do you really want to make it > > compatible with Arduino ? That is, connectors carrying the same pins, with > > the exact same position ? I'm not sure it makes sense, because as for PWM, > > there aren't 6 PWM channels in a 18F2550. I guess Pinguino offers more > > channels but it's in software, not in hardware. Same for ADC: Arduino has 6 > > of them, 18F2550 has 10. How will you deal with that ? > > > (btw have you also check my last try ? > >http://jallib.blogspot.com/2009/08/jaluino-medium-18f2550-based-first...) > > > Cheers, > > Seb > > -- > > Sébastien Lelong > >http://www.sirloon.net > >http://sirbot.org > > > 2009/8/6 funlw65 <[email protected]> > > >> My trial on Arduino layout > > >>http://sites.google.com/site/funlw65/electronics/jaluino-pinguino-28-... > > >> On Jul 26, 12:43 pm, 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 > > ... > > read more » --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "jallib" group. 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