Bare components for Atmega2560 custom board

Other Hardware 3rd Party Boards
1

I asked this before and wanted to go back and reread it, but I've searched for half an hour with no luck.

My project requires more memory, and a second Serial port would be great for debugging, so I'm gonna make my first attempt at a custom PCB with the 2560 mega chip. Is this the bare necessities for components I need?

Atmega2560
16Mhz crystal, and (2) 22pF caps
0.1 uF caps near each Vcc/Gnd pins
10K pullup resister on Reset pin, and 0.1 cap to DTR of my FTDI header

Basically, identical to the bare minimum of the 328P, only with a couple more 0.1uF caps for all the Vcc pins.

Am I correct that any sketch I've made for the Atmega328P will run on the Mega2560 chip, (modifying the pin assignment if necessary)?
Here's my eagle files for starting my project.

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Update: I started with the Eagle Files of the Mega Pro, rather than the Mega. And came up with this eagle file as a starting point for my PCB.
I think this is everything needed to make the Atmega2560 run. I'll replace the resonator with a 16Mhz crystal and 22pF caps.

I notice the mega pro has 10K pull-ups on board for the I2C lines. I always use 4.7K on the Atmega328P. Is 10K better for the 2560?

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Here is the eagle file

Atmega2560_starter.sch.zip (19.3 KB)

4

4.7k vs 10k for the I2C pullups - both are fine. No difference in requirements between '328 and '2560.

In most cases hobbyists encounter, it doesn't really matter exactly what value you used for the pullups - there's normally a fairly wide range within which it will work (the exact endpoints of the range being dependent on the length of the wire, the number of devices, and the speed you're trying to drive it at). 4.7k and 10k are safe choices - they're enough for it to work, normally, but don't load it excessively in the event that you end up connecting a bunch of devices that have their own pullups.

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Here is a screen shot of my minimal 2560 schematic.

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Here's a picture of mine, you can see a Programmer connected to the ICSP header and a FTDI Basic clone on the FTDI header, with a jumper/header to connect (or not) the DTR signal from the FTDI.
http://www.crossroadsfencing.com/BobuinoRev17/
All IO pins are brought out, not just the 70 that the Mega has.

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With the crsytals, Rs, and Cs on the back
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what is the advantage to " a jumper/header to connect (or not) the DTR signal from the FTDI."

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Some people like not having the board reset when the Serial Monitor is opened & closed, which is created with the DTR signal. No signal, no reset.

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Say! That would be handy at times. Like when I plug Adafruits Bluefruit FTDI link in to monitor something.
Thanks.
Your 2560 looks pretty tempting!

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Let me know, we have some assembled & ready to ship (I think). And if not, we have parts to assemble some more.