Rod Lopez

I believe you can use this http://forums.netdui...tion-using-usb/ for basic communication if you plan on having a custom app on ur desktop.

I'm currently using it for transfering a configuration .ini file and storing it in the SD card.

That could possibly do the trick.

Thanks for the tip!

Not sure what's the problem. If you're thinking to a FTDI chip, wired as the Boarduino does, I guess there's no problem.
However, that will be an USB slave, not master.
Cheers

Precisely, I was thinking on using digital 0-1 (or 2-3) as RxTx for a FTDI chip. So what you mean is that it is possible, as long as I don't use the native Netduino USB part. Am I right?

Does your last comment mean that the Netduino's USB can act as USB master? Can I theoretically talk to a slave device such as an iPhone or an Android tablet?

Does anybody have any thoughts on my idea of using UART-to-USB in pins 2&3 and leaving 0&1 as input/output? or using 0&1 with an off-Netduino UART-to-USB chip?

Have you measured the total time for your application to start from a cold boot? I am curious as I would have thought that it would be possible to get that into an "acceptable" range.

As for handling the keyboard and display, why not use a really low power chip (like perhaps the $4.30 TI MSP430 board) to handle that and cause the Netduino to boot as required (like when a key is pressed).

Jonny,
Nope, I haven't really measure it, but the response should be fast enough to feel fluid, probably less than 30ms from button to UI response, that's, I think' way out of any MCU league (other than hardware-interrupt wake up). That aside there are also menu entries displayed that would need updating every second, seems to me like quite a bit of the time for sleep would be spent waking up in such a scenario.

I have thought about having an extra MCU (msp430, atmega328) dealing with the menu/UI side of things, the problem is that it gets more complex both software and PCB-wise, and more expensive to manufacture.
The menu display does require some access to much of the rest of the code. In that sense, for the rest of what the code is doing right now the extra added complexity wouldn't make sense, it would just make sense to simply put the whole code in the msp/328 instead.

Mario, I am not planning to run the device from a 9 volt battery, the battery for my usage is more of large marine type, with a connected solar charger and other loads, that's where the 20mAmp come from Regarding the UI, the device does have a few things attached to it, including a LCD and keypad, the way it is setup right now I raise an event on key pressed and that wakes up the display lighting and a couple of other things. The issue is that, if switching off the whole board, the Netduino wouldn't be able to wake up on time for the UI to flow nicely.