Femtoduino: an ultrasmall (20.7x15.2 mm) libre Arduino compatible board

First picture of Femtoduino

Femtoduino is an ultrasmall (20.7x15.2 mm) libre Arduino compatible board.

By using the QFN32 version of the ATMEGA 328p, 0.05" connectors, 0402 components and removing everything not strictly necessary, I've been able to design and hand build an Arduino compatible board which is very small (20.7x15.2 mm) and ultra light (2g) but has exactly the same computing power of the Arduino Duemilanove or UNO.

Femtoduino has been developed for ultrasmall Arduino prototyping. I had the need to add "Arduino intelligence" to quite small objects (balls, cubes, mices, etc) so I needed to shrink down the size of Arduino as much as possible. Femtoduino is the result.

For regular prototyping, Femtoduino comes with a handy breakout board which breaks out Femtoduino's 0.05" connectors into regular 0.1" pins so that you can use it on standard breadboards or perfboards.

Femtoduino is a true libre hardware project. It's designs are released under CC-BY-SA 3.0 Unported and it has been designed using Kicad, a libre PCB design software.

Femtoduino schematics are based on the Arduino Pro Mini by Sparkfun Electronics and Arduino Mini by Team Arduino.

Video presentation of Femtoduino

Femtoduino Sources and Schematics

Below you find all the sources needed to build your own Femtoduino:

You can get the most updated sources from my personal repository using bzr with the following command:

bzr co http://repository.varesano.net/Femtoduino

Please support the project!

Femtoduino is a true libre hardware project. I released it under a libre licence to allow people to build their own and to give my contribution to the Arduino community.

However, I spent a lot of time designing Femtoduino, so if you are going to use its designs for your own projects or if you plan to sell clones of Femtoduino I'd really appreciate if you could donate me some money to support further versions of Femtoduino or my other libre hardware projects.

Donations can be made using Paypal to my account: fvaresano [at] yahoo [dot] it
Alternatively you cneveran use the donate button on the right sidebar of the page.

Even a couple of dollar/euro helps! Thank you.

Suggestions? Comments?

Please leave a comment below. Thank you.

Femtoduino Project @ Mouser

Submitted by Ricardo Arturo Cabral (not verified) on Thu, 2011-02-24 01:03.

You can get all the parts at Mouser on the following link: https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=b90666...

It's less than 7 dollars!

I've updated the Project on

Submitted by Ricardo Arturo Cabral (not verified) on Sun, 2011-04-10 05:11.

I've updated the Project on Mouser... the 16 MHz resonators were out of stock.
The price stays the same.

Most parts are very small... I advise everyone to buy spares just in case.

Make sure you have good light while handling these parts and during the soldering step.

Have you been able to

Submitted by fabio on Sun, 2011-04-10 06:58.

Have you been able to successfully build a Femtoduino? I'd like to see a picture of it!

http://i.imgur.com/kGCvU.jpg

Submitted by Ricardo Arturo Cabral (not verified) on Sun, 2011-04-10 14:16.

http://i.imgur.com/kGCvU.jpg

Here's what I've built so far... the one on the right is my first try (and first time with SMD soldering too).
I've ordered parts to make 9 more of these for a total of 15 Femtoduinos.

I tried programming my first unit with jumper wires but I've had no luck... so I ordered some breakout boards and 1.27mm breakaway headers.
I may have a short somewhere... so I'm still debugging.

I've had no luck finding a pushbutton for the RST line, the pads are just too small.. I'm thinking of bending a small strip of copper to achieve this.

That's absolutely cool! I'm

Submitted by fabio on Sun, 2011-04-10 19:11.

That's absolutely cool! I'm very happy that you are serious on the Femtoduino! I hope you'll like it and use it for cool projects.

For reset I simply use a small wire to short the two pads together.

Be careful, there was an

Submitted by fabio on Thu, 2011-02-24 01:12.

Be careful, there was an error in the BOM .. you need 2 330 Ohm resistors and only one 10K

Fixed

Submitted by Ricardo Arturo Cabral (not verified) on Thu, 2011-02-24 01:43.

I have updated the project accordingly.
The headers are not included.

Hope it helps somebody who cant order from Digikey... I haven't had luck buying from Digikey myself.

Voltage regulator is missing

Submitted by Anonymous (not verified) on Thu, 2011-02-24 10:43.

Hey, the voltage regulator you choose is not available.. 595-TPS76350DBVR on mouser seems to be a package with exactly the same characteristics of the MIC5205 fabio used.

Alright

Submitted by Ricardo Arturo Cabral (not verified) on Thu, 2011-02-24 14:05.

I've replaced the regulator for the TPS76350 on the project. Price increased to USD$7.32 which is still pretty cheap.

Thanks for the correction.

yes, looks good.

Submitted by fabio on Thu, 2011-02-24 12:18.

yes, looks good.

Great tiny arduino!

Submitted by James (not verified) on Wed, 2011-02-23 22:41.

This looks great! Thanks for sharing!

Thank you!

Submitted by fabio on Wed, 2011-02-23 22:42.

Thank you!

I id love to invest a

Submitted by JohnWS (not verified) on Wed, 2011-02-23 07:02.

I id love to invest a reasonable amount of money in this project, if you can spare a little time with arrangements?

not only because ive immediately fell in love with the board, and really want/need? quite a few for a personal project, im not actually interested in making a profit. even if it were a simple arrangement to have 100 or so manufactured and soldered by a PCB company or someone with decent homebrew equipment, flow ovens etc.

sparkfun are WAY too expensive and commercial, id never sign away my open creations to that place.. maybe sell them a few once demand increases

Please contact me either way,

warm regards,
John W. S

Fempoduino

Submitted by Steve (not verified) on Fri, 2011-05-13 13:21.

I would love to buy some boards off of you if you decide to do that.

Hey John! I'm happy you have

Submitted by fabio on Wed, 2011-02-23 09:33.

Hey John!

I'm happy you have been so inspired by the Femtoduino to actually fall in love for it and willing to have it produced! That's great news!

As Femtoduino is a true libre hardware, the libre license should make you able to build it, even in big quantities, without having the need of any arrangement with me (or at least that was the idea of releasing it as a libre hardware). However, if you prefer having arrangements with me that's not a problem. Just get in touch.

Please note that Femtoduino hasn't been carefully tested (I tested only the Arduino features which I had need for, not everything), so if you plan some mass production I strongly suggest having some prototypes built and then to carefully and deeply test them to remove the possibility of any bugs.

I also have some design enhancements for a possible v0.3 version of it which may be taken into account if you want to mass produce them. Again, get in touch with me.

Of course, if you will make profit out of Femtoduino, I'd appreciate a donation or something, but that's not required. I'm interested in seeing what people with came out with Femtoduino than making money with it.

Ok, talk to you soon.

Fabio

Also interested in manufacturing run of Femtoduino

Submitted by Ron K. Jeffries (not verified) on Mon, 2011-03-07 20:08.

Great little (pun intended) project! This could be a useful accessory to the Ben Nanonote tiny Linux computer http://qi-hardware.com http://sharism.cc

QUESTION: what company did your proto run of the PCBs?

There is (very soon) a UBB adapter (cheap!) that interfaces to Ben Nanonote by plugging into the microSD slot. This allows one to connect a ribboon cable and extend the signals to another pcb.

If anyone is interested in getting a run of Femtoduino and maybe the associated breakout board please contact me: rjeffries [at] gmail [dot] com

Thank you!

ron k jeffries
+1-805-567-4670

Hey Ron, yeah, interfacing

Submitted by fabio on Mon, 2011-03-07 20:19.

Hey Ron,

yeah, interfacing the Ben Nanonote with Femtoduino surely opens many possibilities!

I get all my PCBs from http://dorkbotpdx.org/wiki/pcb_order .. cheap, great quality, ROHS compliant and made in USA!

I hand assembled it. No pick and place machine here.. just a steady hand.

What exactly is an UBB adapter?

Thanks for getting in touch and for your interest in Femtoduino!

Fabio

Bootloader version

Submitted by Daniel (not verified) on Tue, 2011-02-22 18:05.

I have a question regarding what bootloader version/board type you
have been using to program in to Femtoduino?

br
Daniel

Hi Daniel, thanks for posting

Submitted by fabio on Tue, 2011-02-22 20:03.

Hi Daniel, thanks for posting your question here.

I used the bootloader of the Arduino Duemilanove on the 5V 16MHz version of Femtoduino. I still did not built a 3.3V 8MHz Femtoduino but I guess that the bootloader for the Arduino Pro Mini 3V 8MHz should work just fine.

For uploading the bootloader I did used an Arduino Duemilanove used as ArduinoISP. Worked great but only under windows.. that didn't worked on my GNU/Linux PC.

Hope this helps,

Fabio

if you are usind demilanove

Submitted by daniel (not verified) on Tue, 2011-02-22 22:23.

if you are usind demilanove then how is handled reset
as delay to start programing is very short in this bootloader.
is femtoduino have reset circuit on board?

br
daniel

Femtoduino has the reset

Submitted by fabio on Tue, 2011-02-22 22:59.

Femtoduino has the reset logic.. if you watch the video above you'll see that I connected the RST pin of the Duemilanove without microcontroller into the RST of the Femtoduino. Check the schematics for the details.

One more question

Submitted by Daniel (not verified) on Sun, 2011-02-20 00:51.

One more question, where did you get your atmega board, I can't find anywhere that would ship to Brazil, or even italy ^^

Hey Daniel, thanks for

Submitted by fabio on Sun, 2011-02-20 01:18.

Hey Daniel, thanks for stopping by and for your appreciation.

I got the PCBs from http://dorkbotpdx.org/wiki/pcb_order .. great quality, ROHS compliant, cheap!

Hope this helps,

Fabio

sorry

Submitted by daniel (not verified) on Mon, 2011-02-21 00:19.

sorry, i think i expressed wrong, I mean the atmega SMD µC, it's really hard to find on SMD.

Thanks

I got it from Digikey.. they

Submitted by fabio on Mon, 2011-02-21 08:52.

I got it from Digikey.. they should ship to Brazil.
Check http://br.digikey.com/

Thanks!! :D

Submitted by daniel (not verified) on Mon, 2011-02-21 21:26.

Thanks!! :D

Check the BOM file for the

Submitted by fabio on Mon, 2011-02-21 21:30.

Check the BOM file for the actual product code.

Congrats for the project man!

Submitted by Daniel (not verified) on Sun, 2011-02-20 00:31.

Congrats for the project man! I will try to make one in a near future! Just need to figure out how I will make the board yet, hehe.

Would Digikey part

Submitted by tagno25 (not verified) on Fri, 2011-02-18 13:07.

Would Digikey part S9008E-50-ND work for the female connector?

I think so! Looks the same as

Submitted by fabio on Fri, 2011-02-18 13:15.

I think so! Looks the same as what I suggest but cheaper! Cool!

Thank you for shared your hack and using KiCAD.

Submitted by coleoptero (not verified) on Fri, 2011-02-18 12:36.

Great work Fabio.
Thank you for sharing source.
Thank you for using KiCAD for PCB design.

KiCAD grow if used. More libraries will be available. KiCAD improve their characteristics and may become a great alternative to other non-free programs for electronic design.

Thanks again.

coLe.

Thanks coLe for your

Submitted by fabio on Fri, 2011-02-18 12:58.

Thanks coLe for your comment.

Personally, I do already consider KiCAD the best PCB editing option for designing libre hardware. And in my opinion it's already superior to many non-libre PCB design tools out there. Just get a recent version .. the work and improvements the developers have done is huge!

The real question is.. How can you write a libre hardware using non-libre software? Expecially now that there is a valid alternative???

(ehm ehm .. Arduinooo.. I'm thinking about you guys.. )

Cool stuff! I use Pro Minis

Submitted by Stephan (not verified) on Fri, 2011-02-18 08:11.

Cool stuff! I use Pro Minis up to now, but the smaller the better: I would love to buy yours instead! :)

Very cool, thanks for sharing sources.

Submitted by adamfrederick (not verified) on Fri, 2011-02-18 02:35.

Great work Fabio. This can be used in final circuit cause it so tiny. Thank you for sharing source. One question I have is where where I might use that BOM as is.

Thank you! You can open it

Submitted by fabio on Fri, 2011-02-18 08:51.

Thank you! You can open it with Calc in the Openoffice suite using semicolon as separator.

Send this in to Sparkfun

Submitted by scottinNH (not verified) on Thu, 2011-02-17 22:09.

Thank you for your interpretation of the Arduino, and for sharing.

Please consider sending your device to Sparkfun. As I understand it, they could order these from you (and you would manufacture), or they could manufacture these by themselves with credit to you. I really do not know how much money you would net, but even if you are not interested in that it would be good for you to see these mass produced with your name on them. :-)

See: http://www.sparkfun.com/tutorials/92

Modern Device might also be interested..

Seriously... I want to buy one of these NOW! :-)

Hi scottinNH, thanks for your

Submitted by fabio on Thu, 2011-02-17 23:33.

Hi scottinNH,

thanks for your kind comment! This didn't started as a commercial project and I don't really have the time to manage that right now. I may be able to sell a couple of spare boards in the future but that's not my priority for this.

Of course, if anyone would like to build this and sell it, I'll surely be proud of that.

Take care,

Fabio

Sparkfun might make and sell

Submitted by Anonymous (not verified) on Fri, 2011-02-18 14:58.

Sparkfun might make and sell your board, but I think what Scott is saying is that SF will not simply do it because you say it is OK your webpage. There is a little form SF expects designers to fill out...

If you give this to Sparkfun and sign their release form, SF might make their own version (using none of your time). If you do not release it to Sparkfun, Sparkfun might never make it. That is how they work I think.

Lots of people buy the Arduino Pro Mini product from SF. Note that many of the Pro Mini audience would not know how to use MakePCB and then hand-solder SMD parts. It is too difficult, and using MakePCB for 1 board would cost more than the Pro Mini complete.

That is why Sparkfun needs to be told by you, using their form, that you are releasing the design to them. Sparkfun might come out with a newer smaller version of this to replace their Pro Mini. Otherwise this might just be another excellent design that only a few people can use.

I think you might believe that we are asking you to become a manufacturer. This is not accurate. Releasing it to Sparkfun just puts them in charge of it.

If you do not have time to fill out a Sparkfun release form, hopefully some other designer would have time to claim this, or do so on your behalf...

I may get in touch with the

Submitted by fabio on Fri, 2011-02-18 16:05.

I may get in touch with the Arduino team as Massimo lives just 1 hour from where I live.. and see if there could be any commercial interest for this little bug here.

I'll let you know.

I can build these and sell them pre-made

Submitted by Alex Albino (not verified) on Sat, 2012-02-25 01:00.

Hey Fabio, my name is Alex and I live in the San Francisco bay area (USA). I'd be more than happy to start making pre-made femtoduinos. I'm putting together a few of these as soon as the parts arrive in the mail. :-) Thank you for making the femtoduino!

Great! Keep me posted ;-)

Submitted by fabio on Sat, 2012-02-25 01:13.

Great! Keep me posted ;-)

Pre-made Femtoduino boards for sale

Submitted by Alex Albino (not verified) on Mon, 2012-02-27 05:33.

The website to order pre-built femtoduino boards based on the KiCAD/Gerber files is www.femtoduino.com

It will be live by or before March 30 2012.

I am simply providing the service of putting these together. The biggest hurdle right now is just finding the right shop to make the boards in small batches until we can make more of these little critters, but I should have a supply sometime this week. Again, thank you Fabio for making the design publicly available!

I do have all the contacts to

Submitted by fabio on Mon, 2012-02-27 20:39.

I do have all the contacts to have Femtoduinos boards made. I just miss the money. I'll be happy to support the construction of these by getting in charge of production.

Suggestion, please post on the first page of the comments so that people can easily read your messages.

Fabio, please contact me

Submitted by Alex Albino (not verified) on Tue, 2012-02-28 18:42.

Fabio, please contact me directly at my e-mail. We should talk.

Thanks Fabio. I'll do that.

Submitted by Alex Albino (not verified) on Sat, 2012-02-25 01:26.

Thanks Fabio. I'll do that. :-)