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[on:]

Inspired by Nick's UNO pinout I did a similar one for the Arduino Mega2560 R3.



Annotations are color coded. Green have the same function and position as the Arduino UNO R3. Red are differences, where the functionality has moved on Mega2560 compared to UNO. In general, this means that the UNO put several functions on one pin and these have moved to separate pins on the Mega. Blue is for differences due to added functionality (extra pins).

I find it convenient to use the GND pins near to the analog input pins as analog grounds, and to use the GND on the end block for digital grounds, when linking to external circuitry.

Update: correct SCL to SCK, correct colors, call out second ICSP header

[Reply #1 on:]

Very nice!  Thank you!

[Reply #2 on:]

Good job.  Only thing I can see is a nomenclature on the '2560 ICSP header the SCL should be SCK like the other SPI pins.

[Reply #3 on:]

Good job.  Only thing I can see is a nomenclature on the '2560 ICSP header the SCL should be SCK like the other SPI pins.

Thanks! And yes, it should. I corrected it. Also, since the header has the same position and pinout as the UNO, it should be green.

While I was at it, I clarified that the DC input is center positive, and called out the second ICSP socket as well.

[Reply #4 on:]

My friend, we have a nice tool here.  Thanks for breaking out the 16u2 ICSP!

Not that it is needed, but one more thing jumped out.  The I2C "extensional" pins and pins 20 and 21 could be tied "visually", but it could be a little too busy.

Good job again, I like the polarity declaration as well.

[Reply #5 on:]

Wow that's great job! Thanks for sharing!  I wish I found this picture yesterday when I was trying to figure out why my clock and wave shield didn't work when I moved it from Unto to 2560   It safe me hours!   I'm going to print it out and keep at my desk.
That's interesting that there are 2 more I2C connections (unlabeled on the board) above AREF, I thought they weren't connected anywhere. I wonder if one above IOREF does something too?

[Reply #6 on:]

I wonder if one above IOREF does something too?

i know this is a bit late
but looking at the schematics (bottom left, power)http://arduino.cc/en/uploads/Main/arduino-mega2560_R3-schematic.pdf
it isnt connected to anything at all

[Reply #7 on:]

I wonder if one above IOREF does something too?

It's a no connection at this time. The arduino folks just added and reserved the pin position for their future use.

Lefty

[Reply #8 on:]

Thanks for sharing your work!

[Reply #9 on:]

Newbie alert:  So which are d0-d7 lines as you would use for say LiquidCrystal()? 

Thanks,  K..

[Reply #10 on:]

Newbie alert:  So which are d0-d7 lines as you would use for say LiquidCrystal()? 

Thanks,  K..

They are the same as a UNO unless you have a real SPI interface on the LCD.  The current Arduino IDE is default to 4-bit, but if you want to use 8-bit, you will have to specify it in the initialization parameters (LiquidCrystal lcd(rs, rw, enable, d0, d1, d2, d3, d4, d5, d6, d7)).

Check the out the LiquidCrystal tutorial for more detail:
http://arduino.cc/en/Reference/LiquidCrystalConstructor

Also, for a lot of LCD Shields, the 4-bit initialization is different than the tutorial/examples (i.e. LiquidCrystal lcd(8, 9, 4, 5, 6, 7)

[Reply #11 on:]

I got confused by the photo of the Arduino Mega 2560 board with labeled pins. I think that the two pins at the top of the double header over pins 22 and 23 on the right side of the board are 5V pins. Are pins 23, 25, 27, and 29 digital pins? The labels on the photo confused me into thinking that pins 23, 25, 27, and 29 are 5V pins.

[Reply #12 on:]

Ah, I hadn't thought of it like that but I can see how it could be read that way. I will move the "5V pins" label and make it clearer.