It will be a nice challenge. Vasi
On Jan 22, 4:33 pm, Sebastien Lelong <[email protected]> wrote: > Hi guys, > > As I mentioned some times ago, I'm trying to design a new Jaluino board, > named Jaluino Bee because it needs a name. This idea is to provide a very > small board, very cheap, thus using SMD components. It would include a Xbee > socket, as a standard way to plug many different communication modules (real > Xbee/ZigBee, RF, USB, ...). I'm trying to make it as modular as possible. > Depending on usage, user would solder require components or not. For > instance: > > - use USB or not > - crystal or internal clock > - use 5V, 3V3, both or no voltage regulator (none could be used to > directly power the board using batteries for instance). Based on adjustable > vreg LM317. > - or power the board through a serial module or USB > - use I²C or not > - Reset via RTS option > - CTS/RTS option > - connectors for pin header: plug on a breadboard (male) *or* used to plug > potential shields (female) > - ICSP connector > - serial connector > > Attached is a first schematic draft. No PCB design yet, I don't know if all > of this will fit within 5x5cm or smaller. But I guess so. > > Schematic is for PIC18F27J53, SOIC package, but I identified at least 2 > other interesting chips: > > - PIC18F2550: quite common, USB inside > - PIC18F25K22: for high speed application (up to 64MHz), lots of mem, no > USB > > More may also fit. > > As for SMD design, I followed advices and used 1206 resistors and > capacitors, as they are easier to solder. I also wanted to use SOIC package > for MCU, easier to solder than SSOP for instance. There are a lot of > jumpers, due to modularity. I'm hesitating: either using PTH jumpers, or > solder jumpers. First are interesting when tinkering with the board, they > can be always changed. But they are very tall. Solder jumpers cannot be > easliy changed. I then figured out it may be possible to solder 0805 0ohm > resistor over PTH jumper traces (0805 is 0.08" long, PTH space between pins > is 0.1"). This way user can choose between a flexible, ready-to-tinker > modules (PTH) and something more definitive (using 0 ohm resistors). What do > you think ? > > Every component I'm using here seem to be easily available. But because it's > kind of painful to source components, I may provide most of them (except > MCU) if it appeared to be manufactured. > > Any advices, thoughts, feedback appreciated. > > Cheers > Seb > -- > Sébastien Lelonghttp://www.sirloon.nethttp://sirbot.org > > jaluino_v01_bee_schematic.png > 55KViewDownload -- 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.
