1) Communicate verbally and...
2) Be loud enough so that IF it happens to go off, EVERYONE around will know, and (hopefully) call for help.
We all know that many of those battery-powered, $20 alarms that come with double-sided tape that you can mount aren't very loud, and if you DO happen to have one that is REALLY loud, it is your professional, built-in multi $K wired security system. Well, this one uses a microcontroller, which means you can wire the sound output to an amplifier, be it homebrew (DIY) or one from the store.
Here's a video of it in action:
Step 1: Find the stuff
- Parallax BASIC Stamp IIe microcontroller
- Parallax 'Board of Education' carrier board
- RGB LED (I used THIS ONE)
- 220 ohm resistor
- Some solid core wire
- Parallax PIR sensor (you can buy it online, or get it @ radioshack)
- Emic TTS module (from Parallax's online store; I was going to use this for another project, but that one was too big and expensive, and I never got around to it)
- Male header pins (I used THESE)
- Power supply
- Sparkfun connector wires (or any other wires that have crimped, plastic-housed, female connectors on both ends). I used THESE.