I am just trying to gauge an interest level for a hardware/software solution which does the following....
Senses when car is shut off (ACC line loses 12v)
Brings a screen to the foreground with an option to continue on battery power, which if is not chosen within a specified time, results in a hibernation/suspension/shutdown.
This would not really be a replacement for a hardware shutdown controler, but rather a compliment to it.
My current status on this project is as follows:
Using a serial port and a relay to sense the loss of 12v. It is rather easy to detect in software when pins 7 and 8 of a serial port are shorted together. I am currently testing this with a USB -> Serial adapter and a paper-clip, but the hardware is working in regards to this. The circuit for this would be REALLY simple, just one relay and a few wires. USB to serial adapters are cheap.
I've written a simple VB6 app which "reads" that status change on the serial port. A screen with a large button and a count-down timer is then displayed. If the button is pressed (disabling the count-down), the program is minimized and the computer continues operating on battery power until the user or hardware shutdown controller shuts it down. If the button is not pressed, and the count-down reaches zero, then the program takes a shutdown action, which for me is currently using RR's SDK to tell it to hibernate. This action could be anything though (I've done a straight hibernation without RR, using API Calls but I prefer to let RR know the hibernation is happening).
Here is a screenshot of my first version
I know it isn't much, but I saw a GPS unit which does this (Garmin c330) and thought it was pretty slick. If other people are interested in using something like this, I would be interested in making this better(I used a few ugly hacks in my code) and releasing it, probably making it configurable and skinable (currently all configurable options are hardcoded)
Scott