ATMEL Mega1284P evaluation board avalible

adilinden: Are there any plain basic 1284 boards with UNO foot print? The Bobuino is cool but way more features then I need. Essentially need UNO foot print, more RAM then 328 offers and shield compatibility. Be connecting Ethernet shield and a GSM shield. Much prefer on board USB over external FTDI.

The only board I know of with the Uno footprint is this one, http://www.thaieasyelec.net/index.php/Arduino/ATmega32-Dev-Board-Arduino-Diecimila-Compatible-DIP-28-DIP-40-/p_133.html, but it's out of stock and the corresponding Thai page seems to indicate it has been "retired", http://www.thaieasyelec.com/Development-Board/Arduino/Dev-Board/Arduino-Diecimila-Compatible-DIP-28-DIP-40-ATmega32.html.

If you want something that's fully shield compatible (including the location of the ISP header - essential for using the Ethernet shield) then I think my Calunium board is the only other option. The footprint is similar to the Mega2560 footprint (same length, a bit wider). All the files and software are available on Github under a CC license. I had 10 PCBs made by Iteadsutdio for $25, and delivery was just $5. You only need to populate a few and the cost each is about the same as the Uno. You will need an FTDI cable.

stevemarple: The only board I know of with the Uno footprint is this one, http://www.thaieasyelec.net/index.php/Arduino/ATmega32-Dev-Board-Arduino-Diecimila-Compatible-DIP-28-DIP-40-/p_133.html, but it's out of stock

This is certainly a very interesting board. Too bad it is no longer available.

CrossRoads: You want a bare Bobuino board & just populate the parts you need? I could order a batch of PCBs, you build up what you need.

Thank you for the offer. But the board is quite a bit larger then what I would like. I will spend some time on whipping up a board. See how rusty my Eagle skills are. If it becomes too much effort I might just take you up on that offer.

Reading various post here and on hackaday there appears some interest in a much more basic 1284p board. Perhaps doing it would be a worthwhile effort. I also though of creating a very basic vinciDuino or Leonardo clone. Not that I need one but just for practice as it would be low parts count and low cost.

As for USB connectivity with the 1284p, are there any reasons to prefer a mega8u2 (or is it mega8u4?) over a FTDI chip? I think the FTDI chip works out to be about double the cost, at least in very small quantities.

Also, I prefer TQFP over DIP. I tend to not socket DIP but solder them straight to the board in most cases, especially with in circuit programming.

So what you want is a simplified version of this board I did for skyjumper then.

or this, haven’t done the pins_arduino.h file changes yet, this design was made to be pin compatible with existing shields unlike the new Leonardo, which appears to have been designed for ease of routing, with the hardware ports all broken up.

On the Leonardo clone I'd like to do away with external power, only USB. Perhaps as simple as it gets while still having shield compatibility. Yes, I noticed the unusual pin assignment on Leonardo. No surewhat to do there just yet.

On the 1284p I am thinking a whole lot simpler as well.The TQFP 1284p and either an AVR USB TQFP or FTDI for USB. Simple power switching via jumper. Maybe a switching buck converter instead of LDO linear. Have used small integrated switchers a lot in the past. They do work very well, IMHO. Depending on space could allow for either. No idea yet if or how to break out the additional IO pins. I don't need them but then for future might be nice to have them.

Hoping to have time to work on things this week. Having a Christmas break is nice and this design stuff is nothing but a hobby. Actually have a couple of amateur radio needs that got me started. But the GSM shield distracted from the original goal. Have this in my mind instead.

ATMega32U4 with USB only power, like this then.

Haven’t stripped down a 1284 yet, would take me a few minutes.

Okay, I’ve been doing some tinkering.
Here’s a schematic & layout for a DIP based Duemilanove style 366/644/1284 board.
Its intended to have the 1284 mounted on socket strips, so there are a couple of caps underneath the part.
http://www.dipmicro.com/store/HDR40X1FM

I’ll do a version with a surface mount part also

If there is interest, I’ll spring for a batch of 10 or 20 PCBs, and folks can obtain their owm material and build them as they wish.

The IO pins are as defined for my Bobuino, I’ll post the files for that too, designed to be fully shield compatible.
The extra IO of the 1284 series are brought out to another connector. The Analog header has all 8 Analog inputs as well.
Jumper blocks:
USB power or onboard regulator power. Regulator may be surface mount, or thru hole part may be used.
Reset - jumper for reset from FTDI, or leave it open for no reset.
I2C: Jumper to have A4/A5 go to shield, or have SCL/SDA go to shield. SCL/SDA also available on the extra IO header.

There is an onboard 3.3V regulator as well, don’t have to rely on the 50mA from the FTDI chip.

Board is a little longer then an UNO, due to the bigger chip.

Doesn't have the ISP connector in the right place, as required by ethernet shield (was that a requirement, or a suggestion by one of the responders?)

Yeah, that could be a problem accomodating with the big chip. I'll give it a shot tonight.

Well, I cooked up a board. The things a break at Christmas is good for. :slight_smile:

Where are the other IO pins?

I don't know where I posted it in here (or maybe I forgot) but I've the DIP version done with the ICSP relocated, SCL/SDA option in the new spot, and a 10 pin header for the extra IO pins.

adilinden: Well, I cooked up a board. The things a break at Christmas is good for. :)

Cool... I want one :grin:

Hey but can you break out the rest of the pins?? You could make a 2-wide header that goes along an edge, kind of like Maple.

What is the big pad around U1 for? A heat sink?

My primary objective for the 1284P is to get the additional RAM (and code space). Also needed to maintain the traditional Arduino dimensions and header locations, including ICSP. There is more then enough IO on an ATmega328 for my purposes.

When I thought out the board I made some compromises. The 32u4 board I did has a lot of empty space. Could have easily placed a regulator and just choose to not populate if not needed. Once my prototype is tested I just might re-spin with that.

For this board, I ended up with plenty of free space as well. I decided to add a regulator, not thinking of the available IO. In retrospect it may have been more sensitive to dump the regulator in favor of an additional header for the additional available IO. Or could have tried squeezing a bit more. But there is also a time constraint, really needed to get this done, more so then the 32u4 which was just a learning exercise.

So all considered, it is built with my particular specifications in mind. Once I get the boards in my hands might re-spin them anyways. Need to iron out whatever bugs I discover. Also depends if there is any larger interest in the two designs I did. For the 32u4 it would most certainly make sense to add a regulator, there is just so much empty space on the board. For the 1284p I'd be more inclined to drop the regulator and add a header for I/O. We shall see....

Right now I am just tickled by how easy it is to get prototype boards made. I've been pretty absent from this stuff since 2005 or so. Last board I made was a PIC based ethernet board. DIP chips and mix of 0805 and through hole parts. A single sided PCB made at home using toner transfer. Was looking at commercial boards, but cost then was much more for a single prototype run then it is today. If I remember correctly, back then the best deal I found was in excess of $50 for 2 boards. This may have been a bare board without silk screen too. Maybe I didn't look hard enough back then, but I don't think BatchPCB, Seeed Studio or DorkbotPDX were around those days. Anyways, I have been pretty anxious to get a couple of interesting boards whipped up and getting them made. Now I need to wait for the mail man. :)

*man... How many times do I have to edit my post to fix the iPad typos? The auto correct of the iPad is as much of a curse as it is a blessing...

maniacbug:
Cool… I want one :grin:

Hey but can you break out the rest of the pins?? You could make a 2-wide header that goes along an edge, kind of like Maple.

What is the big pad around U1 for? A heat sink?

Yes, played with a heat sink. My first time relying on board copper for heat sink. Used TO-220 and heavy duty metal in the past. So this board is a bit of an experiment to try a few things, and to keep a couple of projects moving that need more RAM then the 328 has to offer.

Will be playing with the board some more based on the outcome of the prototype and any suggestions and ideas I receive here.

I committed this one to being made. I’ll be getting 10 boards in the mail. I only need 2. If the first build doesn’t go up in smoke there’ll be a few bare boards I am gladly willing to pass along.

I've been using iteadstudio and buying 10, 20, 50 boards. 5cm x 5cm, $9.90 10cm x 10cm, $24.90 Shipping to east coast US has been $5, about 3 weeks. There pics at my signature link. Very good quality boards.

Keep seeing these guys in elektor magazine:

http://www.apcircuits.com/ might be worth looking into if in a hurry

I tried a quote, thinking of the '32U4 design that is kicking around elsewhere: Two 1.5 x 0.75" boards, $19.60

"Basic Service: No soldermasks, no legends. Will ship the next business day."

Plus shipping:

"FEDEX is our EXCLUSIVE carrier. There is a minimum charge of $25.00 that covers most Prototype orders."

So that's a drawback! Minimum sizes are also bigger that what iteadstudio will support: trace width, trace spacing, hole sizes.

CrossRoads:
I’ve been using iteadstudio and buying 10, 20, 50 boards.
5cm x 5cm, $9.90
10cm x 10cm, $24.90
Shipping to east coast US has been $5, about 3 weeks.
There pics at my signature link. Very good quality boards.

I ordered from Seeed Studios or FusionPCB. Did not know of iteadstudio. Looks like both have the same cost for boards, but shipping to Canada is $5 with iteadstudio and I paid $8. Not a dramatic difference, huge difference compared to BatchPCB or any other North American offer I have come across.

adilinden: My primary objective for the 1284P is to get the additional RAM (and code space). Also needed to maintain the traditional Arduino dimensions and header locations, including ICSP. There is more then enough IO on an ATmega328 for my purposes. ... So all considered, it is built with my particular specifications in mind.

It looks good, different from Bob's (Crossroad's) Bobuino and also my Calunium, so between us there are a range of options for using the ATmega1284. I hope that somehow we can all collaborate to get the Arduino software fixed so that the SD and other libraries don't make assumptions over pin mapping but use the proper pin-mapping mechanisms implemented in v1.0.

How did you estimate the area needed for the PCB heatsink?

stevemarple: How did you estimate the area needed for the PCB heatsink?

Very unsophisticated.... just used the available space to maximum practical extend.

Apcircuits: 80mm x 100mm - $73.

I think www.internationalcircuits.com will do 10 inch x 10 inch protoboards for $105 or similar. Site says 10% discount for online orders too. skyjumper has been using them, they did yellow board at my signature link. Got another board to post there also when I get home.

Regarding this: "use the proper pin-mapping mechanisms implemented in v1.0" I haven't looked at whats implemented for 324/644/1284, but I do know I disagree with pin mappings used for 32U4/Leonardo, compatibility with older shields disregarded and didn't need to be. Seems to be easier with the Variants folder now to implement a different mapping, need to look into that more.

Seems to be easier with the Variants folder now to implement a different mapping, need to look into that more.

I will have to figure that one out. It seems one can define everything there is to a custom board and place it in the sketches folder. No need to modify any of the original Arduino distributed file. I sure hope that is how it works.

CrossRoads: I've been using iteadstudio and buying 10, 20, 50 boards. 5cm x 5cm, $9.90 10cm x 10cm, $24.90

I second Iteadstudio. I've used them twice now and been happy on both occasions. To maximise yield I used more conservative design rules than the 8/8 mil they recommend. Rounded corners and cut-outs are supported.