Keyless Entry Shutdown Controller
My car has keyless entry, and I thought it would be cool if the computer would start as soon as I unlocked the car, and turn off after I locked the car again. This way, the computer should be completely booted up by the time I have the car started, and it won't turn off even if the car is off, as long as I am still in the car. (So yes, you will need a power supply that can survive a crank).
The circuit I have designed works in conjunction with the shutdown controller here: http://home.comcast.net/~danielsoh/shutdown.htm
My circuit will activate the shutdown controller (turning on the car) as soon as the doors unlock. After the car is turned on, you can unlock and lock the doors at will, the computer will not turn off while the car is on. When you turn the car off, the computer will stay on until the doors are locked. After locking the doors, the shutdown controller will wait a set amount of time before turning your computer off (so you can go in the store real fast without having to restart your computer).
THIS CIRCUIT IS UNTESTED!!!! It should work, but I have not actually tried it out yet.
Depending on how your car is setup, getting to the lock and unlock wires could be somewhat difficult, but due to my cars aftermarket alarm, it shouldn't be hard.
You should be able to find a smaller Hex Schmitt Inverter so that you don't have to waste 5 inverters (or, find a larger one and combine this circuit with the shutdown controller's inverter).
If anyone sees anything I have missed, or has any comments, please share. Thanks.
EDIT: see below for revised version.