raschemmel:
The "old school" hardware interlock method dictates that the power to all of this is wired with something like a DPDT relay so that it can only be powered if the car is not moving (ie: engine off), or at least a removable fuse to disable it while the vehicle is in motion. I am just curious. I have never used one of the types of three axis acelerometers sold for arduinos these days but I have used industrial 3-axis acelerometers and all they were good for was measuring impact g's , so how do these new types allow you to sense level ? I know an inertial navigation system can do that but those are super expensive aerospace equipment . Do the cheap ones they sell at Sparkfun do that ?Several special sensing functions are provided. Activity and inactivity sensing detect the presence or lack of motion and if the acceleration on any axis exceeds a user-set level. Tap sensing detects single and double taps. Free-fall sensing detects if the device is falling. These functions can be mapped to one of two interrupt output pins. An integrated, patent pending 32-level first in, first out (FIFO) buffer can be used to store data to minimize host processor intervention. Low power modes enable intelligent motion-based power management with threshold sensing and active acceleration measurement at extremely low power dissipation.
I don't see anything about sensing level here
Thats what i was getting at. Would i use an accelerometer or a gyro?
Cheers
Jason