Does such a thing exist? Basically, I'd like a switch that would change states when inverted or shaken. I know a mercury switch does this, but it's not the effect I need.
I would like to use this as a power switch for a project I'm working on. Turn the box upside down, it turns on. Turn it again, it turns off.
I know I could do this with a mercury switch and the arduino, but I would really like "off" to truly be "off" -- no power to the circuit whatsoever.
Any ideas?
Any ideas?
A microswitch with a weight on the lever (aka G-switch for the rocket guys)?
-j
Why do you think a mercury switch wouldn't be "truly off"?
a steel ball inside a tube. when turned upside down the steelball would connect two contact points. Basically the same as a mercury switch, but without the mercury which is very bad for the environment and you 
Just wanted to add that my question about "truly off" wasn't intended to encourage you to use a mercury switch.
I agree with MikeMo that a ball tilt switch might be what you want.
Perhaps this would work . . .
action-electronics.com (bottom of page) 500ma @ 24V
Just a word about mercury if I may . . .
I was always pretty cavalier about metallic mercury - seemed no more dangerous than say molten solder. But mercury is different - it vaporizes at room temperature. :o
Check out this little video for a surprising demo . . .
John
Thanks for the replies, guys -- but I think I didn't explain myself well enough.
Here's what I want to have happen:
Instead of a box, I'll use a statue with eyes that light up as the example.
Using a mercury switch, the connection is open or closed based entirely on the orientation of the switch. This doesn't work without having to use the Arduino to watch for a state change. Since this is intended to be used as a way to cut off the power supply, having the chip monitor switch states defeats the purpose.
having the chip monitor switch states defeats the purpose.
well, yeah, if you wire it that way.
if you wire it to interrupt the + lead on the power source, then it is a power switch.
-j
Do you want the whole Arduino board to turn on / of or just the "Eyes" ?
If you can live with just turning the Eyes on / off yon should be able to do it with a tiltswitch and a state keeping variable in your program.
Or even better: sleep mode
I'm intending to break the connection to the entire circuit. Like adding a switch to an LED throwie.
This switch is going between the batteries (or other supply) and everything else. If the switch is open, nothing gets power. I have more than just the arduino in the circuit - there's a TLC5940 plus a slew of LEDs.
By turning the system upside down then back again, you toggle it between on and off states.
So you want to toggle the power with each change in orientation.
Perhaps a little circuit (must always be powered) with a flip flop and a tilt switch that that is responsible for supplying power to the Arduino.
I can barely imagine a unique mechanical flip-flop that would do this. I wouldn't waste the time on a series of prototypes until I got a working version; I'd either hack up something with a CMOS flip flop and oscillator or an 8 pin microcontroller with heavy use of sleep mode. Either circuit would use a small MOSFET to power the Arduino. Both methods should only draw a few microamps.