but i don't get why they're not stackable!? if you placed the analog connectors 2 rows up they'd be, wouldn't they? and i don't see this adding anything to the costs. stackabilty would be kind of a must for me. i'm kind of always dealing with the same modules, like midi-in, midi-out, max7219, button-rows, a nokia lcd...

you could but then youd have to solder to the digital/analog pins on the opposite side because the female header would not be usable. (think about it for a few moments and it will become clear!)

you can if you use wirewrap headers, however. then you can stack the proto shields and use where the female headers go as solder points

umm, they're not really stackable. after some discussion i decided that the number of people who wanted stacking shields was way too small to justify making such a 'costly' design decision.

HOWEVER you -can- just buy 'wire-wrap' headers from digikey
SSA-116-W-T  (etc)
which will let you stack shield...they were just too costly to include in the default design

this protoshield is in beta right now if you have any suggestions its a good time to tell me!


more pix: http://www.flickr.com/photos/ladyada/tags/proto/

the 5v/3.3v shield thing is not a -huge- deal: avr's are (im like 99% sure) 5v compliant so, at worst, it should still work. (if using a r divider, then 1.8V is still higher than most CMOS Vih)

Awesome feedback. Thanks! I am more worried about customers buying Skinny and getting frustrated when it doesn't work with their 5V XBee shield, etc. The ATmega168 should be able to clamp higher voltages without too many problems.

Well, uh, you -did- test it with the XBee shield, right? does it work?

ironically, if you actually solder in female headers to put a shield on it, it will be exactly the same height as a diecimila

The power jack and USB connectors are pretty tall aren't they? And if we're going for pocket-ability, I'm thinking peeps will want to solder in their own wires.

i guess it depends if people are not expecting to put any shields on

The female connectors were a fantastic idea in the beginning. You ever try to desolder a through hold connector like that?  

crush/break the header first, using diagonal cutters, and it will easily come out.

is the 3.3v on the serial connection an input (to VCCIO) or an output (from the internal miniregulator in the 'RL). if its the latter, thats kinda sketchy.  :-/

My designs are always a little sketchy If it sparks, unplug it. If it heats up, you better check VCC/GND. No really - The 3.3V pin on the male header on skinny is an input. The USB board provides 3.3V. You can have the board 'on' and hook up USB without problems. It's a little sketchy to have two vregs on the 3.3V bus at the same time, but both the FTDI vreg and the on-board SOT-23 mini vreg are both pretty burly when it comes to abuse (misuse).

the regulators im not worried about, even a .2V difference they should be able to cope with. what would concern me more is that the internal usb vreg can only provide maybe 50mA. people may plug in the USB thing and notice that the LEDs come on and say "neat i can power it from USB just like an Arduino" and confuse the 3.3V miniregulator with the 500mA USB limit. Everything works fine till they try to connect a 40mA GPS and it just starts to flake and dip into BOD zone. These problems are the hardest to debug...

i like the red pcb & the two LEDs (yay!) - sometimes people dont include them but i think they're essential. the high voltage 3.3v regulator is a good deal too. also digging the .1uF on Aref.

the 5v/3.3v shield thing is not a -huge- deal: avr's are (im like 99% sure) 5v compliant so, at worst, it should still work. (if using a r divider, then 1.8V is still higher than most CMOS Vih)

ironically, if you actually solder in female headers to put a shield on it, it will be exactly the same height as a diecimila

theres no 1k series resistor on RX0, which means if you've got a GPS (or xbee, or xport, etc) connected to rx/tx - many tutorials/examples do this - and the serial link installed (for debugging/uploading) its going to perform very strangely. if its not included, it should be noted

the switch would be 108914981273 times awesomer if it was RA and on the board edge so you could turn it on/off when a shield is on. no big deal tho. (i am rooting for a right angle 3pole switch in the next arduino rev.)

is the 3.3v on the serial connection an input (to VCCIO) or an output (from the internal miniregulator in the 'RL). if its the latter, thats kinda sketchy.  :-/

the fuse seems a bit odd - the diecimila fuse is there to protect the computer's internal usb hub. a reasonable 3.3v regulator (you dont have the part number anywhere so i cant check it) should have short circuit protection. and avr's are current limited on the pin. what would be -really- useful is a power diode, such as a Schottky or 1n400x so when they plug in a 9V backwards it doesnt kill the regulator (good ones have pol protection but most cheap ones dont) and then heaven forbid, if it fails short pass the -9V down to the avr and everything connected to it good news is that you can get 1A diodes in supersmall packages so ya can reuse the pads!  

and one last thing:
i dont really get the 8mhz/'lilypad' thing. i use internal oscillators all the time for cheapie kits, but i'd never do it for a project where customers are expecting to use a serial library where they cant tweak the TCCR values (and where the bootloader is pre-burned with a set value that is not calibrated). i've found that the int oscillator does vary a bit over large runs/temp/voltage. why not include (at least) a ceramic oscillator? you can get a skinny one for $0.20, a full-on crystal setup is maybe $0.35 or $0.40

ok i think im done now

if you want to do that, you can use a vmusic2 module.

well, sd cards are very small compared to -compact flash- cards, which is what ive worked with before. there are mini-sd and micro-sd cards but man, those are small, harder to solder/work-with/not-swallow.
i didnt need more room so thats ok by me!

ok im back from maker faire and PCBs arrived so ive released my wave shield for playing audio. it reads wave files (uncompressed audio) from a formatted SD card
there's schematics, documentation (which is almost done ) , libraries & example code!
i also made a kinda sucky video. woooo!

www.ladyada.net/make/waveshield

yah, the only two 'active' components other than the arduino can't be turned off thru the available pins so not much power to be saved
i used the wdt in a few projects, its pretty easy. heck i used it in my original hack of the arduino bootloader ... i know its in my rev v1.0 of tvbgone firmware, i think i used the ext interrupt to start the wdt to force a reset.

I would add something special to it like a watchdog to wake up the board XX times/minute and a software library to run this using the hardware interrupt.

Thanks for your suggestion David. That sound like a great idea and totally doable. Do you know the part number of the watchdog that would do what you said? I only know the one that can program through hardward, which use external capacitor (larger value cap, longer delay). From what you mention seem like you suggest it to be software programmable.

hmm, why not use the internal WDT?

use hotglue or rubberband

Rubber band! Wow! I hope they use some kind of insulator so the battery won't short the electronic components.  :-?

if you look at the link in my post, the battery holder is made of plastic

i like his idea, becuase the battery is onboard the shield, making it much esier to carry around, no more holding the arduino, your project and the battery, if he makes it correctly, he can make everything connect into one neat little protoboard!

use hotglue or rubberband

http://www.ladyada.net/learn/arduino/starterpack.html#battpack

i had fun with the skillet...and so the USB boarduino kits are finally in the shop!
http://www.adafruit.com/index.php?main_page=index&cPath=19
had to finish the Game of Life kit first

ya i got crazy busy with endofyear stuff and taxes. ill post again when they're all ready to go!