I am working on a low power application that is idle most of the time. It should wake up only when there's some vibration/shake (false positives don't matter that much). What kind of sensor/circuitry could I use for that?
Do a search on your keywords (vibration, shock...), there exists a broad range of such sensors. Choose one with low/zero power requirements, and connect it to an external interrupt that wakes up the Arduino.
Some accelerometers provide a vibration interrupt, but the cheapest, lowest (zero) power option is a shake switch: http://www.amazon.com/Electronic-SW-18020-Sensor-Vibration-Switch/dp/B0094FYPIU
jremington:
... but the cheapest, lowest (zero) power option is a shake switch: http://www.amazon.com/Electronic-SW-18020-Sensor-Vibration-Switch/dp/B0094FYPIU
That sounds good!
I intend to use Arduinos attachInterrupt(0, pin2Interrupt, FALLING) function in a circuit like this:
(debouncing is not a problem in my application)
(from Arduino, Zigbee and Embedded Development: Arduino External Interrupts)
What other options, instead of a shake switch, are there?