design an arduino atmega2561 (64 pins)

Hello everyone.

I am new in arduino´s world. I have a Duemillenove board six months ago and I am very happy. I have tested several times with different programas and configurations and works very fine. Now I have a bigger project in mind and I need to design a special board with atmega2561 (64 pins). The standard boards don´t satisfy my requeriments: low power consumption and no usb adapter, so I have decided to design a special board for my project. I have one question. Can I program my board (atmega2561) as if it would be an atmega2560 board with processing IDE?

Thanks in advance.

Best regards.

PD: sorry for my horrible english.


I'm also thinking of building a custom made, arduino compatible, board with an atmega 2561 or atmega 1281. As this CPU is in the same class of the 1280/1281/2560/2561 series, I presume the arduino programming environment is compatible with this CPU, but I'm not 100% sure.

The atmega 2560 and 1280 are used in the arduino mega boards and are thus 100% compatible. The problem with these CPU's is that they have 100 pins (overkill in my situation) resulting in practical problems with soldering.



This should help.


Dear JanD

First of all thanks a lot for the instructable link. I have read it quickly and it seems very useful. Today I did some searchs and I founded somethings like your instructable, with less details of course. But I make the same question, can I program ATMEGA2561 choosing ATMEGA2560 in board menu? Arduino´s libraries for ATMEGA2560 suports ATMEGA2561?

Thanks in advance


While you probably can, why would you want to? The 2561 has far fewer GPIOs and serials. Your biggest issue here is that the 2561 is only available in MLF and QFP packages, which are incredibly hard to solder (believe me, i've broken more QFN chips than I can count), and require a hot air tool. Your only hope is the 2560, which comes in a TQFP package which is moderately solderable without a lot of expensive equipment. (Just some flux and a fine tip for your iron) Then, you will have to load the bootloader on with an ISP or another arduino. Good luck!

Dear Bilbo

I decided to choose ATMEGA2651 instead of ATMEGA2650 only for the number of soldering. I have soldered several QFN packages without any problem. Also my desition was based that I don´t need all GPIO and serials of ATMEGA2650.

Thanks for your reply and advices.


Ok. In that case, this board appears to have limited support for arduino, and it seems like more is coming:

What is probably more helpful is that the wiring board runs on a 1281, and here is the hardware def for the IDE designed to work with the 1281:

So, you would just need to design and assemble your board, grab an AVR-ISP to load the STK-500 v2 bootloader on your board, install the above patch for the IDE and your good to go!

bilbo’s links seam pretty good, you should look at them. After burning to bootloader on the 2561 on the board in the first link you should be able to program it from the IDE.


Hi to all!
I am new to this, so sorry for my maybye stupid question. But I have similar problem to this…
I´m building 3D printer with minitronics board. I´ve downloaded all materials from here: I made the board myself due to schematic. Standart minitronics boards have ATmega1281 and problem is that schematics in that link say ATmega2561. I didn´t noticed it before, but now I have fully assembled and functional board with mega2561. I´ve tried to burn bootloaders from 1281, it seems to work partly, I can´t connect to IDE and upload MARLIN or other programs…
This state is because proccesor signature is wrong. IDE says expected value is 0x1E9704 but mega2561 have signature value 0x1E9802.
Any ideas how to make it work?
I´ve also tried bootloader from bilbos first link, but same problem… AVRDUDE did not recognized right proccesor… Do you know how to ignore or override this check?
Thanks for any help!