xmega A4 development board

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I have designed a development board for the xmega32a4 and wanted some feedback.

The board has 40 pins in a standard 600 mil layout and has a similar design to the om644p - i.e. it includes the AVR microcontroller, USB socket, FTDI USB/RS232 converter, power LED, USB TX/RX monitor LEDs, 3 port I/O monitor LEDs, a 14.7456 or 16 MHz crystal, and a bootloader for easy downloading of software. The crystal can be used with the xmega PLL generator to support up to 32MHz. The board can be powered from external 3.3V source, USB or an external 4.6-18V source via the on-board 600mA 3.3V LDO regulator. Pins are provided so that a PDI capable programmer could be used to replace the supplied bootloader with user code.

The picture below is an annotated Eagle 3D rendering of board - click on it to make it larger. I like this facility of Eagle but note there are only outlines of the mini-B USB socket and the SOT89 3.3V regulator.

All of the available I/O ports (A, B, C, D, E) are brought out onto 32 pins. The remaining 8 pins are used for power, reset/PDI_CLK, TXD/RXD/ATN and are in the "Basic Stamp" compatible format. Notice the 41th pin for PDI_Data which is only needed for reprogramming and not for normal use with the bootloader.

--Mike

Last Edited: Sun. Dec 27, 2009 - 02:36 AM
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Can you beat the $29 price for the Xplain board with the 128A1?

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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The E.0..E.3 pin group is erroneously marked as Port B.

Warning: Grumpy Old Chuff. Reading this post may severely damage your mental health.

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MBedder wrote:
The E.0..E.3 pin group is erroneously marked as Port B.
Thank you - I fixed the typo.
js wrote:
Can you beat the $29 price for the Xplain board with the 128A1?
No of course not. But that really isn't the point of the board. I'm trying to fit a xmega in a very compact form factor so it is breadboardable and easy to use via a bootloader.

From all that I have been reading on this forum, the Xplain isn't very easy to use and you can easily trash them. My existing Mega bootloader is easy to use, has a self-updating facility and fits in 1K bytes. I plan to have the Xmega bootloader fit in under 2K and therefore leave 30K for user applications. Simply plug into your USB port, start the downloader and the code is updated automatically with no messy boot jumpers.

I would expect a little more thoughtful response, John, with your 10,000 appends and especially after your "experience" with Xplain. Price isn't everything. I do get the fact that cheaper Atmel development tools are probably sold at a loss but that still leaves room for other tools that are better or fill a niche.

--Mike

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Very nice board Mike! Any plans for making an A3 board as well?

Ole

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That does seem like a very strange response from someone with John's experience.

Leon Heller G1HSM

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Quote:
From all that I have been reading on this forum, the Xplain isn't very easy to use and you can easily trash them. My existing Mega bootloader is easy to use, has a self-updating facility and fits in 1K bytes. I plan to have the Xmega bootloader fit in under 2K and therefore leave 30K for user applications. Simply plug into your USB port, start the downloader and the code is updated automatically with no messy boot jumpers.

Do you know xmega boot flash section is in addition of the application section? You will have always 32k available for application firmware. Anything that is less than 4k will give you no benefit unless you want to store some code in the bootloader area.
George.

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leon_heller wrote:
That does seem like a very strange response from someone with John's experience.

No it doesn't - if John hadn't asked it I would. We live in capitalist societies where pirce is set by supply and demand. It's surely a commercial reality that the Xplain, at it's unbelievable price, is going to make it very difficult for anyone to compete. It's true that DIP packaging for breadboard use is the feature that could set this one apart though.

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Given their parlous financial situation it might be advisable for Atmel to charge more for their Xplain board and make a profit on it.

Leon Heller G1HSM

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I'd get one if it was available.

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!

 

 

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_OS_ wrote:
Very nice board Mike! Any plans for making an A3 board as well?
Thanks. No plans yet for an A3 board - I'll wait to see how the A4 board works out. I have experience with TQFP64 parts (see the om128 mega128-based board) so it shouldn't be too hard.

--Mike

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I had a look at the pricing for the Xpain. In the US it is $32.50 not $29. The pricing for my board will be between $34.95 and $39.95. Larger quantities (25 or more) should keep the price to $34.95.

--Mike

Last Edited: Thu. Dec 31, 2009 - 08:39 AM
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Xpain - I like it! Or, is it a Freudian slip.

Put me down for one.

Leon Heller G1HSM

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Looks like a nice board. I like the concept of a usable and simple design to get started using the xmega. Less is often more.

I roughed out a design for an xmega128A1 board that is similar. I placed it in the project section under "low cost xmega". That is as far as I got. Perhaps you could clean up my design and market it too. I would likely buy both.

It all starts with a mental vision.

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Looks something hobbyists may want: module you had NO problem to solder by hand (forget SMDs..) in your application. And (maybe) leave it there with app developed. (That would NOT - I think - be case of XPlain)

At least IF it would be affordable for hobbyists...

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mikeperks wrote:
I had a look at the pricing for the Xpain. In the US it is $32.50 not $29. The pricing for my board will be between $29.95 and $34.95. Larger quantities (25 or more) should keep the price to $29.95.
Arrow NAC in the US had it for $29, single quantity. However, to get it to Europe would in the end have cost more than $75. ($10 handling charge, $10.22 "handling and energy fee" (WTF?), min. $26 freight).

NuHorizon asks for $32.50. And slaps you with a minimum order surcharge of $67.50 for the privilege to buy from them. Plus shipping and handling, of course.

Mouser asks for 24,31 Euro, approx. $36.60, muses about a potential need of an export license and asks for 20 Euro shipping and handling to get it to Europe.

Stealing Proteus doesn't make you an engineer.

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Quote:
That would NOT - I think - be case of XPlain
Why not? In addition to the Xmega128A1 and the 90USB1287 you also get 8 MEGABYTES of sdram, 8MB Serial Data Flash, 8 switches, 8 Leds, a speaker and 2 1/2 ports for your own use. If you need more I\Os and don't need LEDs or swicthes then you have "easy" access to 2 more ports.

Anyway I was not in any way denigrading Mike's efforts, I hope he sells lots of those boards and becomes as rich as Bill Gates.

And NO, I don't have any problems with the quality of the Xplain board, it's very well made and I would have purchased it at twice the price. Any issues, now resolved, were of my own making.

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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KitCarlson wrote:
I roughed out a design for an xmega128A1 board that is similar. I placed it in the project section under "low cost xmega". That is as far as I got. Perhaps you could clean up my design and market it too.
One thing I noticed is that you are routing power through the chip. This is a big no-no and each power/ground pin should be individually supplied. Not a big problem to fix, even for a double-sided board.

I have a xmegaA1 development board layout already done with PCBs due to be delivered this Friday - but that is a separate discussion for another day.

--Mike

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ArnoldB wrote:
Arrow NAC in the US had it for $29, single quantity. However, to get it to Europe would in the end have cost more than $75. ($10 handling charge, $10.22 "handling and energy fee" (WTF?), min. $26 freight).

NuHorizon asks for $32.50. And slaps you with a minimum order surcharge of $67.50 for the privilege to buy from them. Plus shipping and handling, of course.

Mouser asks for 24,31 Euro, approx. $36.60, muses about a potential need of an export license and asks for 20 Euro shipping and handling to get it to Europe.

For future reference, I offer low cost shipping to Europe (basically Air Mail) which is around $3 depending on the weight. There are no other surcharges. At this price there is no tracking but they haven't lost any of my packages yet, even in Italy.

--Mike

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ArnoldB wrote:

Mouser asks for 24,31 Euro, approx. $36.60, muses about a potential need of an export license and asks for 20 Euro shipping and handling to get it to Europe.

@Arnold

Watterott wants 31 Eur , but only 10 Eur EU in shipping (up to 20 Kg)
http://www.watterott.com/Atmel-X...

He has 24 in stock , and i just bought.

@Mike Nice board , especially for breadboarding.

/Bingo

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This board seems to be a very different creature than the Xplain. No buttons or LEDs or onboard memory, a lot smaller (1/3 the size?) and twice as much of the IO is brought out. I can't imagine many cases where it would make equal sense to choose one or the other.

Mike

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kk6gm wrote:
This board seems to be a very different creature than the Xplain. No buttons or LEDs or onboard memory, a lot smaller (1/3 the size?) and twice as much of the IO is brought out. I can't imagine many cases where it would make equal sense to choose one or the other.
Exactly, which is why I cannot understand John's insistence on comparing it with the Xplain. I do have 3 onboard LEDs but on fixed I/O pins and the board is 1/5 the size to be more exact. For this device I leave the I/O up to the user and let them plug it into any circuit of their choice. This is much harder to do with the Xplain.

--Mike

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Bingo600 wrote:
@Arnold

Watterott wants 31 Eur , but only 10 Eur EU in shipping (up to 20 Kg)
http://www.watterott.com/Atmel-X...

Ah, the small business beats the big ones. I remember having bought from them in the past and received good service. So lets see.

Stealing Proteus doesn't make you an engineer.

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Looks like a nice board. Atmel did finally release the XPLAIN to distribution, making it a very hard price point to meet for third party stuff.

I whipped up something similar for the AVR32 UC3B1256:

http://store.stackfoundry.com/copper-avr32-stick.html

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Quote:

which is why I cannot understand John's insistence on comparing it with the Xplain.

But Mike, at this stage mnost of us are just looking for a "toe in the water" experience with the Xmegas. An LED and a button is probbaly about as much as anyone really requires in fact. If anyone can deliver this for $30 or less they are probably onto a winner. The cheaper the better in fact - at this stage I don't think most "hobbyists" necessarily have a big project in mind but just want an "easy in" to learn about X - whatever form that takes.

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clawson wrote:
But Mike, at this stage mnost of us are just looking for a "toe in the water" experience
Toe? Na, this guy got it right :)

Stealing Proteus doesn't make you an engineer.

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Thank you for all of your comments.

I found room to add another 100n filter cap and thickened up some of the traces from 8mil to 10mil. The design is now ready to go to manufacturing - I use Gold Phoenix. I will post some pictures when I get the first one built and tested. I decided on a name too - omxa4.

--Mike

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I have built and tested the omxa4 - everything works as expected. I have a limited quantity available now without a bootloader - just click on the picture to order. I will make more available with a bootloader in 10 days.

Until the bootloader version is available you will need a PDI capable programmer such as AVRISP mkII, AVR Dragon, AVR JTAG mkII, or STK600. I have verified that the AVR Dragon with AVRStudio 4.18 SP1 can program a xmega32A4.

--Mike

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mikeperks wrote:
kk6gm wrote:
This board seems to be a very different creature than the Xplain. No buttons or LEDs or onboard memory, a lot smaller (1/3 the size?) and twice as much of the IO is brought out. I can't imagine many cases where it would make equal sense to choose one or the other.
Exactly, which is why I cannot understand John's insistence on comparing it with the Xplain. I do have 3 onboard LEDs but on fixed I/O pins and the board is 1/5 the size to be more exact. For this device I leave the I/O up to the user and let them plug it into any circuit of their choice. This is much harder to do with the Xplain.
I see the XPlain as an evaluation board and this as a development board. This lets you breadboard with it and all the I/O is accessible... looks good.

I was working on something like this for the A3 but I couldn't quite get it to fit... it was just a little too wide.

This looks great! THIS is (in my mind) how you get a toe in the water.