Which one is the working Due version?

hiduino:
I just received two Due's in today. They were ordered from the Arduino Store the same day it was listed online. They both look just like the "current one" in the first photo.

Yes get the same today works like charme

That did not explain that the crystal for the RTC is missing

Who has one with the RTC Crystal can tell me what on the surface so I can order me one by my self

Markus_L811:
Who has one with the RTC Crystal can tell me what on the surface so I can order me one by my self

I don't think there is a due that has the crystal. No one has reported that they have gotten one.

neslekkim:
Ah, ok, I got a bit confused on this picture: http://arduino.cc/forum/index.php/topic,128464.0.html
The GND next to 3v3 and 5v is marked as "use for analog ground"

Yes. That is more of a 'serving suggestion'. If you have a bunch of of-board digital circuitry, and also a bunch of off-board analog circuitry that will be feeding the built-in ADC, it helps to keep digital hash out of the analog circuits by using the GND pins right next to the ADC inputs as an analog ground. (Also by using aseparate 5V or 3V circuitry, perhaps using screened cable, unity gain buffers, and so on).

On the board though these five GND pins are all commoned together. There is not an inductor-isolated, separate analog ground on the board itself.

The photo in that thead will be replaced by Graynomad's much more detailed diagram, so there is probably little point in my updating it to clarify the 'use for' part.

Ah, ok then I understand.
Yes, the new layout looks like it will be very good, not that yours wasn't, but placing all extrainformation like what Graynomad is doing now is great.
Then it's up to all of us to check if it is correct.

Would be fantastic if some of the people behind Arduino also was a part of this..

neslekkim:
Ah, ok then I understand.
Yes, the new layout looks like it will be very good, not that yours wasn't, but placing all extrainformation like what Graynomad is doing now is great.

I'm happy that there is a better version available to the community.

neslekkim:
Would be fantastic if some of the people behind Arduino also was a part of this..

Yes. One could argue that they are in the best position to document these things and check them.

okay1984:

Hey guys,

I'm going to manufacture few pieces of Due PCB boards, but I'm really confusing about this above. The small chip 74LVC1G125DCK has been moved to left bottom corner. Seems that's the right position.

The current EAGLE file released on Due production page matches the second one board in that picture. So it's not the latest one.

Hope Arduino team release the latest one soon.

Best,
Tony

And the Story goes on,

I have buy just for fun an secound Due from ebay. And now there are the diff.

On the Due from ebay is everything the same, the box, the sticker and the package insert it looks in all way like the actuell one with all labels on the surface, except one part it has the Crystal for the RTC on the surface.

With this I have make an test I used stimmers Sketch for the http://arduino.cc/forum/index.php/topic,130125.msg980484.html#msg980484 RTC and put this in the void setup to use the external Crystal.

#define SUPC_KEY   0xA5u

void setup() {
  Serial.begin(9600);
  SUPC->SUPC_CR |= SUPC_CR_KEY(SUPC_KEY) | SUPC_CR_XTALSEL;
}

So there we are if I used the internal RC the RTC lost 5sec in 1 Min so it is nearly 10% to slow with the external Crystal is goes sync with my PC clock.

and I don't understand why all of you get Due's with proper markings and even the jtag header soldered.

Seems like one is better off buying from ebay than through official channels, what a shame.

Thanks, that's useful to know. Could you have a close look under a magnifying glass and tell me if the capacitors next to the crystal are also missing? I'd probably be able to solder the crystal back on if I needed it, but the capacitors would be impossible.

The only situation where this would be important is if someone needs real-time accuracy in low-power mode (otherwise the RTC can be emulated in software). It would be interesting to see how much power the Due takes with the SAM3X in a very low-power state.

Thanks, that's useful to know. Could you have a close look under a magnifying glass and tell me if the capacitors next to the crystal are also missing? I'd probably be able to solder the crystal back on if I needed it, but the capacitors would be impossible.

I can,

From Arduino Store now Crystal no capacitors.

From eBay Crystal and capacitors.

neslekkim:
and I don't understand why all of you get Due's with proper markings and even the jtag header soldered.

Seems like one is better off buying from ebay than through official channels, what a shame.

The Due I received from Mouser has the crystal and the JTAG header.

I'm still confused. What does the (supposedly official) schematic on the downloads page indicate? RTC xtal or not?

If it is present in the schematic but not on (some) of the boards, what does that mean? Manufacturing goof-ups?

I must admit if plunked down the dough for one of these things at the full official list price, I'd be annoyed if I got one that didn't have the RTC. For $49 + shipping and taxes (and possibly more, depending on where you live) I'd expect something fairly premium, with all the bells and whistles. After all, not exactly cheap for uC dev board, considering the alternatives...

What does the (supposedly official) schematic on the downloads page indicate? RTC xtal or not?

The schematic shows the RTC xtal. There is no DNP (do not populate) or similar annotation so if they are not on a delivered PCB I'd say you have cause to complain if you need it.


Rob

pico:
I must admit if plunked down the dough for one of these things at the full official list price, I'd be annoyed if I got one that didn't have the RTC. For $49 + shipping and taxes (and possibly more, depending on where you live) I'd expect something fairly premium, with all the bells and whistles. After all, not exactly cheap for uC dev board, considering the alternatives...

Excactly. I'm dropping this crap, heading in the stm32 direction again instead.

Markus_L811:

Thanks, that's useful to know. Could you have a close look under a magnifying glass and tell me if the capacitors next to the crystal are also missing? I'd probably be able to solder the crystal back on if I needed it, but the capacitors would be impossible.

I can,

From Arduino Store now Crystal no capacitors.

From eBay Crystal and capacitors.

Thanks again.

I tried soldering on a watch crystal by itself and it is not enough - in fact it is worse, only 42 seconds per minute! With capacitors it runs at a more conventional 60 seconds per minute :slight_smile: But there is no easy place to solder the capacitors on (I was literally holding them between the crystal and the shielding of the USB port, which can't have helped the accuracy much).

Thanks again.

I tried soldering on a watch crystal by itself and it is not enough - in fact it is worse, only 42 seconds per minute! With capacitors it runs at a more conventional 60 seconds per minute :slight_smile: But there is no easy place to solder the capacitors on (I was literally holding them between the crystal and the shielding of the USB port, which can't have helped the accuracy much).

Capacitors are really really important for the Crystal to work proper, they needed that the main frequenz of the Crystal swing. On page 1407 of the full SAM3xa is an formel to choose the right value.

Do we really need to calculate this??? on an product that is randomly shipped with or without crystal?, with or without headers?, with or without labelling on the board?

neslekkim:
Do we really need to calculate this??? on an product that is randomly shipped with or without crystal?, with or without headers?, with or without labelling on the board?

Wrong question its not the point if you get an board with or without an crystal, if you want an working crystal/RTC with the most possible accuraty you need the right capacitors. So the question is what is the right value. In the schematic the value are 22pF but the Spec says max is 20pF...

Well, I bought a board, that I expect to be complete.