RAMPS 1.4 with Mega ADK

Hi
I'm trying to build my first reprap printer and I'm planning to use a RAMPS electronic. In order to keep the door open to the ability of controlling my printer with an android device, I would like to change the Mega2560 with a MegaADK. I can find some clues about this topic, but no details:
- On RAMPS page I read about a change

Quote

Servo1 connector moved to pin 11 to free 7 for ADK

- I read over Ultimachine about a complete upgrade to Mega ADK, but no details.

Do someone use a RAMPS with a MegaADK board? Where can I find proper firmware/hacks? Will other RAMPS optional SDramps or LCD/SD) be compatible with ADK board?
Thanks in advance.

There is no problem at all to running a Ramps hardware board attached to a 100% Mega compatible hardware board with any software tool chain that will support the Mega cpu. If you wish to write your own firmware, there is no limitation at all. The existing firmware is tightly linked to the Arduino libraries and porting it would be a non-trivial exercise. Since the firmware is actively being developed you would very much have a moving target.

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Next layer to the onion is the Mega CPU it's self. We aren't causing them to go up in smoke from over work, but we push pretty hard. Dropping something else in on top of the firmware would have to be done with care. A lot depends on which printer you are running and how fast you want to run it.

Edited 1 time(s). Last edit at 12/30/2013 05:02PM by uncle_bob.

The difference between Android accessory and normal USB device is which end takes the role of USB host, and as the Mega ADK uses a separate USB chip over SPI to do this, it probably doesn't cause significant CPU load; however, the firmware would need to be changed to read from this interface instead of the normal USB interface.

As an easier alternative, the Android OS does also support normal USB, but not all Android hardware does, and battery life could be a problem.

My concern is not the com traffic when running normal printer stuff. The concern is that doing Andriod specific enhancements may add a significant load to the Mega.

Thanks for your replies.
Rebecca got my point of view: with a usb-host capable ramps, I can use every cheap android device. In my mind (not sure at all, need to verify), the adk firmware do things to connect to the device, then the normal printer firmware start without modification or added load.
I hope to be able to replace the LCD/SD extension for ramps with an android touch screen device and print a file stored here, without a PC or a SD (thanks to WiFi and a file server).