The Armalite, SAM3 32-bit "Arduino-Due-compatible" design

I like this a lot. I don't have any applications in mind yet, but I didn't have any for the Arduino before the beginning of this year, either. Now I'm up to my neck in them. If this is available for anywhere near the price point of a Mega, for example, that's darned attractive.

My one gripe.. which I only mention to feel out the possibilities: Let's say I end up finding applications for this. How would I go about moving it from the dev board into my own project? With a 'duino, I can breadboard or PCB up a bare chip. How easy would it be to adapt a minimal ARM setup if I wanted to OEM my design? Suitable for one-offs, or would it only make sense if I intended to buy in bulk and sell them as finished products?

I started another design that was basically just a breakout board for the SAM. Something like that could be used however I don't think breadboarding will be practical with a 144-pin chip because with 96 IO plus other pins the breakout board will over 5" long if you stick with two parallel rows of pins.

However IIRC many breadboards are 64 holes long so that would work.

As with all board that use these large SMD chips the model of moving the chip from Arduino to OEM board is no longer applicable.

You could use this board in a finished product if the features were what you needed, as always though if you don't need all the features you are paying for stuff you don't need. I have tried to stop the feature creep and this is a fairly simple board, but there are things on it that will not be used on many applications.

I'll return to the breakout design I had and see if I think that will fly.


Rob

You could provide some pins for breadboarding, and then a "virtual breadboard" on top of the breakout for the other pins -- say, through female header rows or something.

Let me try this from a different angle...

How difficult is it to design a minimal ARM environment? Assuming a breadboard is out of the question, if a designer has basic PCB design abilities, is it something reasonably accessible to a hobbyist? Or are we talking four-layer boards and routing skills that require an experienced engineer?

Also, how forgiving of questionable layout are these, at ~100MHz? By that I mean, do you have to understand RF propagation theory, and know why or why not to choose fiberglass as a substrate, or can you get along with some basic understanding of ground planes?

100 MHz is not fast enough that RF theory is needed, AFAICT. However, I don't imagine you'd be happy if you run a clock signal through 10 vias and two laps around the board :slight_smile:

I really don't think there's a lot of room in the market for something like this, though. It's already super crowded. If you want simple software, and a wide range of compatible plug-and-play hardware, you need shield compatibility, and ideally Arduino IDE compatibility. For everything else, the Raspberry Pi really hits the nail at $35 (or $25 without networking.) And, if for some reason you don't like those, there's still a phletora of boards like mBED, LPCExpresso, BeagleBone, PandaBoard, Gumstix, etc.

How difficult is it to design a minimal ARM environment?

AFAIK (and remember I haven't got a board made yet) it's not difficult, all the signals seem pretty straight forward. I am using a 4-layer board with power and ground plains mostly because it seems like a good idea and makes the layout a LOT easier. Whether or not it's required I don't know.

Also, how forgiving of questionable layout are these, at ~100MHz?

100 MHz is not fast enough that RF theory is needed,

Bear in mind that there really isn't any 100MHz stuff outside the chip, I have paid special attention to the USB and microSD signals. Also external memory is on the backplane so it's a fair guess that it won't run at full speed.

Most other signals are normal IO which shouldn't be too hard to handle. The SAM also has on-board terminating resistors on all IO pins.

I really don't think there's a lot of room in the market for something like this, though.

Quite possibly, I've always done things for the fun of it so that doesn't really matter to me.

That said AFAIK none of those board have this combination of features, whether or not these features are of interest to people is another story :slight_smile:


Rob

Just for fun, a very rough mock up of a breadboardable no-frills version in the "aircraft carrier" form factor.

It would need two BBs but I don't see any problem with that.


Rob

A recent tweet from the Arduino team

the processor is a SAM3/X from ATMEL

This is one nice chip (depending on the actual model used), looks like a re design is in the air :slight_smile:

Also hopefully this snippet of information means the release is close.


Rob

I also have my eye on the Beagle Bone, but if yours were available (either form factor, though the BB-compatible one suits my taste better), I would have to get a couple. For what it's worth.

So, is this still on the cards now that the Due (and the 1.5 toolchain beta) is available?

Afraid not, as I said on the other post I've pretty much lost interest in doing a Due clone, mostly because I think there are about 500 people doing just that as we speak, not to mention existing boards like the Teensy 3.0 that have a similar form factor.

I am working on an ARM board at present and will send off for PCBs today probably. But this is a dual processor board with an LPC1227 and an Atmega1284 designed for monitoring and control networks, a totally different idea to the above.


Rob

Fair enough (I was aware it was an old thread, but was curious to see if there was ongoing work). Thanks for responding.

I think there are about 500 people doing just that

yeah; I've come to realize that there are any number of "interesting" sort-of-arduino systems that could be made, that aren't really much good for the community as a whole. If anything, there are already too many variants...

If anything, there are already too many variants...

Like trying to decide on which toothbrush to buy these days.

I suppose my board won't help but it certainly will have a point of difference for what that's worth.


Rob

I get that Armalite is a play on words for ARM , but Armalite is a trademark of the company that invented the M-16 rifle which was originally called the Armalite and they have kept those trademarks current. Are there no gun geeks here?

http://www.armalite.com/Categories.aspx?Category=538b8c3c-6710-4282-839f-fb5caf8043a3

Yes, at the time I thought that may be a problem if the board went anywhere. Probably not a good company to piss off eh :slight_smile:

It's moot though because I won't be making the board.


Rob

Hi,
I'm looking for "very simple" design of Due (I need fast processor, huge memory but I dont need more ports).. Any one developed one? or what should be the "minimum" components that sufficient to run "AT91SAM3X8E" in Arduino environment? many thanks in advance, reha

reha:
Hi,
I'm looking for "very simple" design of Due (I need fast processor, huge memory but I dont need more ports).. Any one developed one? or what should be the "minimum" components that sufficient to run "AT91SAM3X8E" in Arduino environment? many thanks in advance, reha

You really need to define what you mean by huge. I think the SAM3X supports something like 128 MB.

I haven't seen any SAM3X board with an external memory though. For a minimal design, look in the Due forum.

Teensy 3.1?