Transfrmr/ Relay / Switch ???? Nwby needs help!!

I am new to all of this, so bear with me on this question. Coding doesn't scare me. Neither does soldering. But I lack a rock solid foundation in electrical engineering. I have a decimilia on it's way (couldn't get my lilypad working), and i already have an adxl320 accelerometer. This is what I want to do:

I want to measure the acceleration of a cell phone (in your pocket while walking or in a car) AND when it stops, i need to shut it off. I took it apart and looked at the on/off button, which turns out is some kind of a funky looking push button switch of sorts (round disc that caves in when pushed and closes a connection between two contacts). It closes a circuit, that to the best of my ability is measuring .5V (I just bought a digital multimeter today and am going to verify what my analog meter says). I need to control this switch with another switch. I have been studying up on relays / transistors / gates and such, but i cant figure what i should use to close this connection for 2-3 seconds when the phone stops and then again when it starts moving.

Any ideas or suggestions or if someone can point me in the right directions, I would be gratefull.


the safest and easiest way to control a switch on the phone is with an optoisolator. Use Google to search this forum for more info, as it has been discussed many times. If you look in the playground there is a tutorial linked form there on controlling an IPOD using optoisolators-- this will give you the general idea. Cell phone soldering is not easy... things are tiny in there.