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16  Forum 2005-2010 (read only) / Development / Freeduino Pico on: October 05, 2008, 10:48:18 pm

We've made some significant changes to the Freeduino Mini so much so that it needed a new name: the Freeduino Pico! As far as I know, it's the smallest Free(Ar)duino variant with built in USB. Its about 1/4" smaller than the previous version of the mini and yet we've added a barrier diode 'voltage selection' and reverse protect circuit, added a 10uF tantalum capacitor for better filtering, added a 10kOhm resistor on reset, brought ARef out to its own pin, and reduced it to a standard 24pin package.

To do all this we had to move from a through-hole crystal to a .05% tolerance surface mount resonator, move from 0603 parts to 0402, the weak 3.3v feed from the FTDI232 had to be cut, and the two 'extra' ADCs we moved off to the end of the board. (Yes that means this is 5v logic level from USB although I suppose if there was enough demand a 3v version could be made...)

The above pic is of the most recent working hand soldered (yes I hand soldered those 0402 parts smiley-razz) prototype with an admittedly bad quality silkscreen run. We are looking to fix this and get this manufactured in due time.

All the best,

17  Forum 2005-2010 (read only) / Development / Re: Seeeduino - an unofficial update of Diecimila on: September 05, 2008, 03:40:09 pm
Im with kg4wsv, the CP2102 is a seriously flawed device and would make your board no longer 100% compatible IMHO.

If size is the problem you can get the ftdi chip in a MLF package which would be great for machine assembly but good luck to you if you want to hand solder your protos. For that mater the same goes for the ATmega168 just look at pololu's mini orangutans.

Finally reconsider your license... there has been these debates on the fora about derivative works and how they should always be distributed with the same license as the original. Last I knew Arduino was under the cc2.5 license.

18  Forum 2005-2010 (read only) / Development / Re: What do YOU want on an Xmega Arduino? on: August 21, 2008, 07:58:51 pm
The ATmega8 to 168 migration is a relatively no-brain drop in replacement that doesnt really affect the strategy of the Arduino concept. As is I assume the 328 migration will be as well when/if that ever happens.

Now, Dave has hinted at a big Arduino whatever that turns out to be. The question here is at what point is it no longer an Arduino? When should a fork leave the Arduino name behind? Im all for a more powerful uC with a compatible language that allows an entry point for non-ubergeeks but I think riding on the coattails of the Arduino concept sems a stretch.

To be perfectly honest Id like to see an even smaller uC! Ive used the PICAXE 08M for years and its surprising what can be done with an 8pin uC.


19  Forum 2005-2010 (read only) / Development / Re: Freeduino Mini USB on: August 11, 2008, 11:00:42 am
An update....

20  Forum 2005-2010 (read only) / Development / Re: Freeduino Mini USB on: July 11, 2008, 08:36:49 pm
Im still working on it... Ive added a reverse protection diode and a method for connecting aref to 3.3. Ive got a batch of the second prototypes in front of me but haven't made the time to finish them up.

If there's still enough interest in it after the metaphorical landslide of recent 'duinos, we will make it available before too long.

21  Forum 2005-2010 (read only) / Development / Re: Freeduino Mini USB on: May 14, 2008, 08:53:17 pm
Lemor, where'd you go? Im curious about the LED question!

After some creative soldering and green wire work, I got the RX/TX Led working happily. That was a dumb little mistake! Quick little fix in Eagle though and I think Im ready to go. That is unless I have to cram another LED in there....  smiley-grin


22  Forum 2005-2010 (read only) / Development / Re: Freeduino Mini USB on: May 14, 2008, 10:56:28 am
Is that super necessary? The 232 eeprom can configure that single led to reflect both rx and tx. (I think by default gpio0 is rx and gpio1 is tx but in this case gpio0 will be set to both rx and tx, once i green wire it.) Did you have something else in mind?

23  Forum 2005-2010 (read only) / Development / Re: Freeduino Mini USB on: May 13, 2008, 11:57:02 pm
@ Nathan: D'oh! Thanks so much! I knew there was something and it was staring at me all along. Ok, Ill get on that and fix it up.

Otherwise, Ive managed to get the pin13 LED crammed in there. I flipped the xtal and row of caps/resistor which allowed me to juggle it a bit and get it wired up as suggested. The question here is, is the led too far away from pin13 and/or how should it be labeled?

Past that, Ive tweaked some of the spacing and little minor things but I think its close to another proto run. Any more suggestions?


(Pending COM led fix...)
24  Forum 2005-2010 (read only) / Development / Re: Freeduino Mini USB on: May 09, 2008, 08:27:12 pm
So Dave Im not sure whether to wait or try to beat you to the punch!  ;D

I will see what I can do about the pin13 led. Maybe theres a way.

I stuck with the FTDI 232 because Ive heard the drivers are more stable cross platform than the CP2102. I could have used its smaller package but that would be a pain to prototype so I didnt. And honestly Ive used this chip before so I stuck with what I knew!

Speaking of that chip, Im having a hard time enabling the rx&tx led on that general purpose i/o pin its connected to. Im using MProg to change the 232r eeprom but its not seeming to make a difference. Has anyone done this?

Im hesitant to go with pth mini-b just because thats going to increase the difficulty of assembly. Sparkfun uses the same method of assembly that I do and they will typically use the same part. Something to try out tough.


25  Forum 2005-2010 (read only) / Development / Re: Freeduino Mini USB on: May 08, 2008, 04:22:04 pm
Yeah I agree too. I tried to cram it in there but it was awfully tight, and ruined the symmetry too! I put the resistor in there because it did fit and a cheap led isnt too hard to hook up for an indicator light. (I still have my NG!) Maybe there is still a way.

26  Forum 2005-2010 (read only) / Development / Freeduino Mini USB on: May 08, 2008, 04:14:31 pm
Hello all,

I thought it might be interesting to introduce a Mini variant that did two things: have built in USB for easy interface and did away with Basic Stamp conventions so that all i/o pins are accessible by the breadboard. Designed in the spirit of the BoArduino and RBBB but surface mount with no assembly required (in production), as small as humanly possible, and includes the 2 extra analog pins as a bonus. Oh and it had to be Diecimila compatible with the auto reset and 500mA fuse!

So here is the first working prototype of the Freeduino Mini USB. I have already made some changes to the design as you will see in the schematic and board images largely because of a boneheaded mistake not to bring out the reset pin. So the next prototype will jump from 24pin to 26pin making room for RESET and 3V3 and moves those pins around to make them a little more standardized which it may or may not be. The size will stay the same at 1.75" x .65" (think longer basic stamp). The next version will have larger and hopefully more readable text labels. Also, I brought out an LED from the first IO pin of the FTDI 232 chip so Id like to hear what you think the purpose of that LED should be: power on, tx&rx, ?? (Im leaning towards tx&rx). Otherwise let me know what you think in general.

Once the design has been tested thoroughly (at least 1 more proto run) I will publish the files (based in part on the Freeduino reference) and then if the interest is there we will see about getting some distribution for it. I am also planning a Sans-USB version and maybe a lower part count, USB Key version (think memory stick) whenever time allows.


27  Forum 2005-2010 (read only) / Development / Re: xport fun on: February 11, 2008, 02:54:04 pm
These shields look really good. At the risk of sounding like a complete n00b, what basically is the difference in the xport and xport direct besides the fugly plastic case of the direct? The specs seem very similar so what am I missing?

28  Forum 2005-2010 (read only) / Development / Re: Arduino Monome shield group buy on: August 14, 2008, 06:03:01 pm
That seems a very curious thing to stipulate in open source-ness. Where do we go with that? 'You can freely use this design but only if fabricated by my uncle's cousin's best friend Bob?'

29  Forum 2005-2010 (read only) / Development / Re: Arduino Nano on: May 22, 2008, 02:07:12 pm
Sure its an interesting design but I dont know if its a good design. One of the attractive things about the Arduino concept is that it made embedded electronics democratically accessible by ease of design, ease of interface (ie usb and mac compatibility), and affordability.

How many times has there been a comparison to the Basic Stamp that IIRC is priced at $50 and has always been railed for being too expensive. I ultimately feel that cramming the full functionality of the arduino into a longer-than-Stamp-sized form factor at the trade off of having to have dual-side components and 4 -layer pcb resulting in a costly board with ground effects is not a very good tradeoff and might be heading in the wrong direction.

I assume the forthcoming second big announcement the Arduino team will be making is that of a 128 or similarly based arduino and Im sure that will be placed in a similar price point. Im just saying that it should be possible to gain almost full diecimila functionality in a small form factor fully assembled for $30 or under and to do it while embracing the tenants of a community driven open source hardware initiative. Whew.


[Edit: I realize this may be taken as a rant but please dont read into it in that way.]

30  Forum 2005-2010 (read only) / Development / Re: First Standalone PCB on: July 26, 2008, 01:20:31 pm
The resistor isnt needed, but RESET should definitely be connected to +5v otherwise you might get intermittent resets.

As for the power jack there are 3 connections being: +V, GND, and SWITCH. That 3rd pin is to detect when the power has been plugged in or not. Otherwise it is just tied to ground. I dont use that part myself but I think the order should be:

1. +VIN
2. GND
3. GND

If you look at the part itself, it should be something like:

|   |
| O |
|   O

The top two should go to GND and the bottom connects to +V.... on most center positive power supplies (which is sort of a standard for arduino and related boards). YMMV, depending of course on what part you are actually using.

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