hello whosawhatsis, is it possible to have a pcb layout in eagle or other format? thanks a lot.
All of my designs are kinda in flux, I haven't been keeping old versions of the files like I probably should have, and the current versions are all untested and need a lot of cleanup. I'd really rather wait until the "final" version to distribute the files.
In the meantime, here's a peak at my newest design. It's a similar concept (tiny, breadboardable arduino with a .3" span), but this one is all-SMD. BTW, I never would have guessed that a TQFP would be easier to solder than a 603...
lookin good 
i havnt tried a smd type arduino yet.
I'm thinking that a cylindrical package could work, but I can't find any that are less than 8.8mm long, and I only have a clearance of ~ 7mm. Anyone know of a 16 mhz cylinder crystal that's shorter, or know if it would be a problem to mount it at 45 degrees, or laid flat above its capacitors? I've never used one before, but what I've read suggests that they're more sensitive about their environment than other components.
There aren't any cylindrical crystals shorter than 8.8mm that I know of. The ECS is slightly shorter than the Citizen one and doesn't exactly match the datasheet dimensions.
It is possible to put the crystal on top of other components and in particular the AVR chip. See the OakMicros om644p for an example. of course the mega328p is a smaller chip than the mega644p. You should avoid long traces for the crystal and have the caps also close by. I think a crystal is far superior to a resonator as it is more accurate and less prone to drift.
Check the size of the 16mhz crystal used by the Seeeduino Mega, it's the package closest to the avr1280 chip and measures about 4mm X 3.2mm.
Lefty
Check the size of the 16mhz crystal used by the Seeeduino Mega, it's the package closest to the avr1280 chip and measures about 4mm X 3.2mm.
I've found some really tiny smd crystals that I might use with my smd board, but I'm looking for the smallest pth package.
Small update to the mini version. I moved the reset capacitor under the chip, making the board that much smaller and look that much more like perf board. It's now quite possibly the smallest possible arduino board. Here are some pics, with comparisons to the previous version.
sweet XD
Smallest board I have seen is here :-).. made in Thailand
From www.duinothumb.com
Hah, I actually designed one a while ago with the same formfactor, but I never had one made because I was more interested in breadboard-friendly designs. Mine also had a voltage regulator, which that one doesn't appear to. I don't see an eagle file or schematic for that one.
The SMD design obviously produces a thinner product, but the effective area of the circuit board is the same .64 square inches as my mini board, with approximately the same features (mine has a second led and an autoreset solder jumper, that one has a reset button). If it's a competition, I can move my solder jumper to a less accessible location and cut out the .02 square inch area that it's using 
I think I can get this arduino down to the same footprint as the DIP row with some creative layout and tracing.
Would the preference be using a mega168, or the newer mega 328?
Not sure what you mean, I've already got it down to the dip footprint, plus a breakout for an ftdi header, which can't go under the chip for obvious reasons. I think the layout is already rather creative.
I've been working with the 168 for prototyping, but I can always drop in a 328 as a replacement
Sorry, didn't make myself clear. I can reduce it to the same footprint using all SMT components where possible. I think your DIP layout is absolutely brilliant.
I'm working on redoing my SMT board with the pins in a DIP layout, and I'm also hoping to get the whole board down to the width of the usb connector. The routing has been giving me problems, but I designed an FTDI board today, and the process gave me some ideas for how to do the layout of the other one.
Minor update. This one was really just a test to make sure a crystal would fit, and now that I figured out where to put it, it fits even better than the resonator.
The next boards are already in production. They are rebuilt from the libraries up to be even smaller and more streamlined.
Great work...
Are they going to be sold soon?
How much would you be looking at?
Thanks,
Mowcius
Here are my newest boards. I finally got my "thumbduino" idea to work, and it's a pretty nice little board, if I do says so myself. The analog pin numbering is backwards and I've already fixed that and added markings to indicate PWM pins for the next round of boards. The redesigned wirewrap boards are .02 square inches smaller than the duinothumb.com "world's smallest" board.
Great work...
Are they going to be sold soon?
How much would you be looking at?
Thanks,
Mowcius
I need to do a little reworking because the pin labels are too small on the rebuilt version, which means another round of batchpcb prototypes, which takes the better part of a month. If I'm satisfied with the next version, having a panel made should be significantly faster. Does anyone have suggestions other than seeedstudio for where I can get these made one panel at a time for a decent price?
I'll have to do some math once everything including the pcb supplier is finalized, but I think I could sell the wirewrap board kits for under $20. The thumbduino board would be a little more.
I need to do a little reworking because the pin labels are too small on the rebuilt version, which means another round of batchpcb prototypes, which takes the better part of a month. If I'm satisfied with the next version, having a panel made should be significantly faster. Does anyone have suggestions other than seeedstudio for where I can get these made one panel at a time for a decent price?
I'll have to do some math once everything including the pcb supplier is finalized, but I think I could sell the wirewrap board kits for under $20. The thumbduino board would be a little more.
I read somewhere (on hackaday I think), which fab house batch pcb uses and they are pretty cheap for a panel. I'll have a better look later but I bet someone else knows what it is. If you want to so them in seperate boards then you could use ourpcb. Just send them a design and they will send you a quote. Once you have had one production run done you can get later runs done at a cheaper price because you don't need to pay the tooling charge for the same design.
$20 sounds pretty good, I want it for a permanent project where the board needs to fit in 1" tube which is impossible with a duemilanove. Are the boards having the 168 or the 328? Could you use either?
Btw, what voltage does the board need? From the looks of it, I would need an external voltage regulator, correct?
Thanks,
Mowcius
I've been using the 168 for prototyping, but I'll probably sell them with the 328. They are all designed for 5V operation. The smallest one does not have a power regulator, but the extended version adds that (7805 or 78L05), a reset button, and an ICSP header.
A 1" tube would be a tight fit. The total assembled height is about 7/8", but for a permanent installation, you could probably bend or trim the pins to get it down to not much more than half an inch.
Of course, the Thumbduino without headers installed would fit a tube half that size.