Custom Built Arduino Mega with a Atmega2560-16AU

Hi All,

I have been building an Arduino Mega clone board with the larger atmega2560-16au chip and wanted to share my experience with everyone :sunglasses:

I also used make with the source code of the bootloader to create the .hex in windows, I also built and used the usbasp to flash the .hex with avrdude just for fun :smiley:

here are the images of the board for now will update later


blank board:

more bits ready almost to start:


1st board complete:

I have some videos and more pictures I will update :wink:

so far I have build 8 of these boards of which I only needed 1 ;D
I sold a few on ebay I quite enjoy building these boards and plan to make at least another 10 :smiley:

btw I had to order 25 atmega2560-16au chips so until I have a custom project they are spare ::slight_smile:

I want to get my hands on the newer atmega8u2 board and have a go at that, so if anybody got any spare boards give me a shout :sunglasses:

any questions just ask

I have been wanting to build a mega clone myself. If you dont mind my asking, is there a tutorial anywhere on how to assemble the board? Is there a list of parts needed? I would like to do what you did and just buy the board, and then solder all the components on. Thanks for any guidance or suggestions you may have.


I have not found any tutorial but you can get the parts list (bom) from eagle reference design but here is my parts list

Qty Device Parts
1x reset switch S1
1x DIODE-SMB (SS14) D1
2x 0805 LED (yellow) RX, TX
1x 0805 LED (red) L
1x 0805 LED (green) PWR
1x USB Type B X4
6x 0805 1K Resistor R1, R7, R8, R9,R11,R12
5x 0805 10k Resistor R2, R3, R5, R6,R10
3x 0805 22pF Cap C2, C3, C11
11x 0805 100nF/0.1uF Cap C1, C4, C5, C9, C10, C12, C13, C14, C15, C16, C17
2x 100uF Tantalum E case C6, C7
1x 500ma fuse F1

1x ATMEGA1280-16AU IC2
1x ATMEGA2560-16AU IC2

1x 2.1mm power socket
1x FT232RL IC6
1x LM358D IC7

1x MC33269D-5.0 IC4
1X MC33269ST-5.0T3 IC5
1x LD1117DT-5.0/LT1117DT-5.0

1x NDT2955 PMOS SOT223 T1
1x FDN340P PMOS SOT23 T2

1x Double row 2x18 Female header 2.54mm
1x Double row 2x3 Female header 2.54mm ICSP1
1x Single row 1x6 Female header 2.54mm Power
5x Single row 1x8 Female header 2.54mm

I had to order some parts bulk so it is more expensive to build 1 board than buy a prebuilt my break even point is 10 boards (£25-£30 per board) and 20 boards (£20-£25 per board) and it takes about 2 hrs per board for building and testing.

the bootloader can be a pain sometimes it will burn from arduino 0021 without a problem but a few didn’t and I needed another programer (usbasp) and used avrdude in command line to flash and set fuses

I have spare parts so I could do a kit, I can also make a tutorial when I get some spare time if you wanted :slight_smile:

Thanks for the reply. I am going to price out the parts list and see what the parts can be bought for here in the US. I will probably just use the 1280 chip. Please post the tutorial if you make one as im sure I wont be the only one interested in seeing it. I will post my findings on US pricing once I get it together. Thanks again.

I updated a part number for IC4
from "MC33269d-5.0"
to "MC33269DT-5.0G"

IC4/IC5 is a fixed 5v LDO regulator in a TO-252-3 (DPAK) or a SOT-223 package. e.g 1117 5v sot-223 on mouser is "LD1117S50TR"

I've done alot of searching, and it appears that the Mega or a knockoff can be purchased off eBay for only a few dollars more than it costs in parts. Guess I will just be buying them assembled. I already bought a new Duemilanove from one of the eBay sellers that assemble them in-house and it works perfect. Thanks for the help BlueDragon.

What does the 2560-16AU accomplish better?

Just more memory resources over the 1280

What does the 2560-16AU accomplish better?

yes more memory space for program

Atmega1280-16au = 128K -4K ~ 124K for program
Atmega2560-16au = 256K -8K ~ 248K for program :smiley:

total space - bootloader = total space for your program

I have some more boards for sale on ebay and I should also have the video tutorial done by next weekend