pascor:
Thanks, I found this diagram when I first looked. But, I want a schematic diagram, not a layout diagram.Also, there's no up-to-date schematic diagram available for the Mega2560 board, either.
Are the designers at Arduino sloppy, or just lazy ? There's no good excuse for not providing accurate documentation.
No need to start a flame war nor use language that is inflammatory. After all, the vast majority of folk here do their thing for free. As such, some gratitude is in order... I simply marvel how easy the work of others has made it for me to program all sorts of things.
The Mega 2560 documentation page includes a schematic as well as the eagle files that list all components, the layout, etc. You can download eagle for free and then use the ULP bom function to get a BOM of all used components. Hence the ease with which current boards are modified by others to serve new purposes.
Last but not least, before we cast stones at the Arduino team, it might be worthwhile looking at some competitors' sites. For example, the Digilent ChipKit foray into an "Arduino-compatible" form factor does not feature a prominent disclosure re: a schematic or the components on the board. You get pin designations, and that's about it. Not sure how much wider the Arduino folk need to open their kimonos, from what I can tell everything one would need to use a existing board as a start-off point is already there.