On Fri, Feb 4, 2011 at 8:59 AM, Sebastien Lelong <[email protected] > wrote:
> Hi guys, > > > So...I'm back, after several tries. > > It was possible to keep most features, specifically providing 2 voltages, > 5V and 3.3V. This was quite a mess though, mostly Xbee requires 3.3V, and > possibly voltage shifter on inputs (datasheet says it's not 5V tolerant, but > some report it is in reality). So I removed 5V regulation, and kept only > 3.3V, making this board more 3.3V devices friendly. If Xbee isn't wanted, > then one would just put an AMS1117-5V instead of 3.3V version. > > I worked again on power supply inputs. There can be 4 sources: USB (5V > regulated to 3.3V), external (5-9V regulated to 3.3V), serial (no regulation > so must output 3.3V, quite rare), and battery (direct, no regulation). I put > a fuse after the regulation part. > > Since I had some room left, I added a microSD slot, though I still wonder > how I'll solder it... :) It's on the bottom side. If replacing 3.3V > regulator with a 5V one, again SD-card won't work. > > I doubled shield/breadboard connectors to allow breadboard + shields at the > same time. User could also solder some wires to plug the board to external > daughter, using external connectors/holes. Shields can also be on top or > bottom, both, etc... > > I may also add another pin header which would include supplied voltage, > making it available to shields/breadboard (voltage coming from USB, > external, ...). > > Anyway here's the result, see attached files: schematic, PCB, PCB top, PCB > bottom (some comments are wrong, sorry). > > > Feedback appreciated. Highly ! > Your designs looks better and better. However there is HUGE empty space on your board. Look for example the footbal field between the crystal and the micro. When using SMD one of the reason is miniaturization. But your board is still huge. You cand do it with only 20% larger than the xbee itself? Vasile > > > Cheers, > Seb > > > 2011/1/30 vasile surducan <[email protected]> > >> >> >> On Sat, Jan 29, 2011 at 10:49 AM, funlw65(Vasi) <[email protected]>wrote: >> >>> I think you will need to design two boards. One supporting USB uCs and >>> second for serial uCs. Keep 1206 smd components, otherwise you must >>> provide the board assembled. And this is because of 5x5mm limit. >> >> >> >> >> >>> Try >>> to see how many features you can put on a single type of board. >>> >> >> all you need... >> >>> >>> Vasile >>> >>> >>> On Jan 29, 6:03 am, Sebastien Lelong <[email protected]> >>> wrote: >>> > Hi guys, >>> > >>> > Here's my last version, including a 500mA fuse (not resettable, but I >>> only >>> > have this one in my eagle lib), a rectifier diode for reverse polarity >>> > protection, onboard LED moved to RC2 (CCP1 pin). Some remaining >>> "doubts": >>> > >>> > - which package would I need for the diode: DO-214AA, DO-214-AB or >>> > DO-214AC ? >>> > >>> > - I still have doubts about the power supply part. Initially, I >>> wanted to >>> > have power through USB or a battery. The board should handle 3.3V and >>> 5V, as >>> > an option. When using a battery, say 2 x 1.5V AAA cells, I'd need to >>> bypass >>> > all regulation (maybe even a pump like this: >>> http://www.sparkfun.com/products/9216). Using a rectifier diode will >>> also >>> > drop the voltage down and may not be compatible. But I could also use a >>> 9V >>> > battery, and thus need 5V and/or 3.3V regulators... and what if 3.3V is >>> > bypassed, but not the 5V regulator ? Xbee board will be powered with >>> 5V, >>> > instead of 3.3V!!! You guessed it, I want many things and I'm not sure >>> which >>> > is most important at this phase. Any input, advices ? I think when I'll >>> > start to create the PCB choices will be easier to make as I discard >>> options >>> > to gain room :) >>> > >>> > - I added pin headers, 2 x 14 pins, I may add another one dedicated >>> to >>> > power pins (like in Medium) if I get enough room (I doubt about it) >>> > >>> > In order to save some precious room, I'm thinking of (high priority to >>> low): >>> > >>> > - removing Reset-via-RTS option and make it always available (2-way >>> jumper >>> > saved) >>> > - remove two I²C jumpers, always make the board acting as a master, >>> and if >>> > not wanted, just don't solder the resistors >>> > - remove CTS jumper option (not used often ?) >>> > - remove power from serial module option, focusing on USB or battery >>> > - keep only one regulator, adding an optional resistor to match >>> required >>> > 3.3V for Xbee when using 5V reg only. >>> > - move to 0603 smd components..... >>> > >>> > Any feedback highly appreciated! >>> > >>> > TIA >>> > Cheers, >>> > Seb >>> > >>> > 2011/1/25 mattschinkel <[email protected]> >>> > >>> > > > Maybe I should just use two different voltage regulator, one >>> AMS1117/5V >>> > > and >>> > > > AMS1117/3V3. Having only one component would have helped while >>> sourcing >>> > > > them. >>> > >>> > > On one prototype board I bought, there is only a AMS1117/3V3. They >>> > > assume you want to input > 5v and get 3v output. If you want another >>> > > voltage you can put a jumper (just solder) to connect the >>> input/output >>> > > of the regulator so your voltage is whatever the input is. >>> > >>> > > Matt. >>> > >>> > > -- >>> > > 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. >>> > >>> > >>> > >>> > jaluino_v03_bee_schematic.png >>> > 62KViewDownload >>> >>> -- >>> 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]<jallib%[email protected]> >> . >> For more options, visit this group at >> http://groups.google.com/group/jallib?hl=en. >> > > > > -- > 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]<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. 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