i was really interested by the barebones arduino project and sketched up 2 alternative layouts.
the first one is meant to plug like a DIP chip into a breadboard. it is 3"x0.8". there is a 5V 1A regulator on one end with a standard 2.1mm barrel jack. The digital and analog pins, as well as aref, vcc and gnd are brought out on the sides. at the end is a standard 6-pin isp connector and a reset button. there are 2 LEDs, one to indicate powergood and one thats for general use, its connected to sck which seems to be 'standard'. there is a 6-pin connector for a USB-TTL cable ($20 from mouser). you can also plug in a usbmini adaptor onto the end if you use the end pins. you can also plug it on on the side, theres 4 pins that are gnd, 5v, tx, rx in order. if you plug it into a breadboard there are 2 breadboard pins on both sides so you can connect to it with wires.
the second one is kinda like the barebones arduino. its 3.5"x2" (credit card size). There's the shield jumpers as usual, as well as the standard 1A 5V supply, there is a 9V battery holder on the back, looks like this: http://rocky.digikey.com/WebLib/Memory%20Protection%20Devices/Web%20Photos/BH9V-PC.jpg. There is also a DC/DC boost supply that can take 2 AA batteries and provide 250mA. You can use either the LDO or the DC/DC but not both. i had space so i added a 10-pin ISP connector. theres a long strip of header at the bottom so that it can plug into a breadboard (kinda like the barebones arduino). there's a header for a USB-TTL cable.
im thinking of having both kits in my store and seeing how they do, would be about US$20 (without the 9V battery holder or the boost converter) ill be getting some PCBs made and trying them out. ill post again when i have them assembled with photos.
awesome designs! Why not make the top design have .6" wide, and also replicate the Arduino Mini pin mapping?
D
PS: I think the power jack is 2.5mm, not completely sure. The SCK connection is to Arduino pin 13 for the blinking led tutorial, the cornerstone of newbie happiness...
PPS: welcome to the forum
awesome designs! Why not make the top design have .6" wide, and also replicate the Arduino Mini pin mapping?
i could probably squeeze it to .6" but it might be tough, the power supply is about as tight as possible and the chip is wide enough already that it would be hard.
since it has the throughhole parts its already pretty large so i decided to bring all the pins out. its not pincompatible because its so much bigger and also the mini doesnt bring out the analog pins.
Just curious, why switch to the 10 pin header on the larger board? IIRC, the same signals are present as the 6 pin, just in a different form factor, so this would just mean you need an adapter if you're set up with a 6 pin cable (for example the avrispmkII).
Just curious, why switch to the 10 pin header on the larger board? IIRC, the same signals are present as the 6 pin, just in a different form factor, so this would just mean you need an adapter if you're set up with a 6 pin cable (for example the avrispmkII).
inexpensive bitbang programmers often only have 10-pin cables because it is not possible to buy assembled 6-pin cables
I just wanted to say that I am a huge fan and admirer of your work.
I'm just now watching the video of you with Phil Torrone at OSCON, and that promo for the Digg Button that you did with Kevin Rose was the best podcast, ever.
I'm really excited to see that you're a part of the Arduino community. I'm sure you'll bring amazing projects with you.
Hmm. TOO many different layouts will reduce the utility of the "shield" cards.
I really like the second (shield compatible) layout. Very clever to finesse the
slightly off-grid shield/power connectors and an on-grid set of pins for protoboards
in the same layout, and I really like the idea of having a battery supply available.
nope, but it does plug into the "cheapest" card-edge connector available from digikey
not sure what that would be used for but i thought it would be an interesting addition.
only problem is you cant plug it in once youve soldered on the shield connectors. we shall see....
i think both designs offer benefits.
PCBs arrive tomorrow from Gold Phoenix, we'll see whether my designs are any good when assembled!
OK I built and started testing out my breadboard arduino clone. I had two mistakes but they are easy to fix so next revision will be perfect
Managed to program the bootloader using the 6-pin ISP cable and then uploaded sketches that blink the red LED and also send/receive data using a USBmini-type thing as well as a USBttl cable from mouser
Your efforts are really interesting. Youve almost made a non-mini mini! Im in the middle of designing some boards for projects I have in the fire (to be shipped off to gold phoenix via sparkfun) myself so I appreciate the attempt at 'building a better mousetrap'. Although Im curious, this latest board of yours and pauls barebones leaves me asking, is it barebones enough? Why the inclusion of the vreg, status leds, and second serial header at the far end? I imagine you could bust it down to 2" and chip off another $5 without the extra parts. Then it would be as barebones as you could get while saving some time wiring the reset button, icsp, resonator etc. Its just a thought but I like extremes.
And on a side note, can anyone tell me the difference between these boards that use a resonator vs the original 'duinos that use an xtal & seperate caps? Any reason to use one over the other?
Anyway, interesting designs. I cant wait to see what use you come up with for the card edge board.
do you think there's space to put pin identifying numbers on? The newbie crowd needs that. Me too these days, or better glasses.
It's a very tight layout though... maybe stickers for the breadboard, between the power busses and the rows? Like training wheels.
D
Your efforts are really interesting. Youve almost made a non-mini mini! Im in the middle of designing some boards for projects I have in the fire (to be shipped off to gold phoenix via sparkfun) myself so I appreciate the attempt at 'building a better mousetrap'. Although Im curious, this latest board of yours and pauls barebones leaves me asking, is it barebones enough? Why the inclusion of the vreg, status leds, and second serial header at the far end? I imagine you could bust it down to 2" and chip off another $5 without the extra parts. Then it would be as barebones as you could get while saving some time wiring the reset button, icsp, resonator etc. Its just a thought but I like extremes.
sure. and some people have done that. but i have a pretty strict idea of what i consider 'minimal' for something to be an arduino clone. some people say "why did you include an ISP header" and some say "why did you include a 9V dc plug and regulator?" but if you think about it, these are all essential and create a good value for a lot of users. Basically it comes down to "this is what I think is a good design for the most number of people at this time." In the future, there may be different layouts! But I gotta start with something solid. Anyways you can always cut the 5V regulator and USB headers sections off with a saw
And on a side note, can anyone tell me the difference between these boards that use a resonator vs the original 'duinos that use an xtal & seperate caps? Any reason to use one over the other?
crystals are slightly more resiliant to temp and voltage changes and, in high quantities, may be cheaper. the resonator is 'just as good' for most of our requirements
do you think there's space to put pin identifying numbers on? The newbie crowd needs that. Me too these days, or better glasses.
It's a very tight layout though... maybe stickers for the breadboard, between the power busses and the rows? Like training wheels.
D
i will try to do that in the next revision by removing the circles around the pins. although the text would be -quite- small !
This mini board is awesome looking. I wish there was a 3.3V output also, that nowadays many electronic parts started to have that voltage. And I think would be really great to have the program load / run switch close to the reset button too.
Well, I have to wire this stupid switch if I'm using another serial controlled device which has to share the serial bus. I'm using Lantronix X-Port for ethernet connection for this. When in run-time, it doesn't know whether it's in the program monitor mode or run-time, so nothing comes out of TX line.
I like those optional but practically mandatory LEDs already mounted on the board. My mini-arduino on a breadboard looks messy having to wire those 2 LEDs, the reset button, and program load / run switch with a pull-down resister.
Suggestion: Move the D8, A0, A5, and D7 to the SIDES of their respective pins, and make them bigger. That way you'd have more legible "reference markers" even if the other pin labels are unreadable...
Also, If you use one of the silkscreen re-sizing ULPs, you'll get an alternate layer for the silkscreen whose individual elements are editable; you could probably make the D8..13 and a0..5 bigger by getting rid of (or moving slightly) some of the lines on that DIP package (of course, they might end up partially covered if you use a socket for the chip, but it might still be useful.
Suggestion: Move the D8, A0, A5, and D7 to the SIDES of their respective pins, and make them bigger. That way you'd have more legible "reference markers" even if the other pin labels are unreadable...
thats what i had before, and it was actually more confusing, i think, than just having them on top
Also, If you use one of the silkscreen re-sizing ULPs, you'll get an alternate layer for the silkscreen whose individual elements are editable; you could probably make the D8..13 and a0..5 bigger by getting rid of (or moving slightly) some of the lines on that DIP package (of course, they might end up partially covered if you use a socket for the chip, but it might still be useful.
ya thats where the socket goes, so messing with the silkscreen wouldnt really help
