Actuator Switch: Source and Type

How does this look?

http://www.novitatech.org.au/product.asp?p=247&id=1734

Or how about a 'foot switch"?

http://www.delcom-eng.com/products_USBFSW.asp

Or how about a real panic button?

http://www.firebox.com/product/1742/USB-Panic-Button?src_t=wnw

I had a similar idea several years ago. I was thinking about a computer based security system with a battery backup and a modem connected to a cell phone that could call authorities even if power and phone lines were cut. I think pretty much any type of an "On-Off" switch should work for what you are asking. I'm not real sure how the computer reads the USB port to identify which device your switch would be. I'm assuming it's by frequency within a bandwidth. Anyway, name your switch in your program, and have your program run in the background doing a Loop Until routine. I hope this helps.

Hello. Why do you want to connect it to your computer and use unnecessary wiring and create yourself a headache? Program a PIC for control and another for wireless transfer to an LCD carried with you (example: remote control of an AC). You can also forget about the PICS, and program a 86000 Motorola microprocessor. This way you will have a real computer under your hands.

www.sparkfun.com has a lot of modular components. You could combine a cell module (for dialing out), a mp3 player (with a recorded message), a button (to push of course) and small controller to interface it all together. From a hardware point of view it is pretty simple but you'll have to spend some time learning about digital electronics (how each module communicates) and about the programming necessary to make the button trigger events on the mp3 module and cell module. There are already 1-button cell phones for alzeihmer's patients...there a gps on board too so it'll report it's location if you call it or look it up on the web. This isn't as fun as making your own though. Have fun!

That switch link that guest sent looks like a good USB panic button. If it can open a window it should be able to play a wave or mp file.

I have been using a very cheap web cam with free motion detector software for years as an intrusion alarm. At any sign of motion my speakers loudly announce " Your picture has just been sent out on the internet. Have a nice day." When I lived in an apartment I had the cam pointed at my door. I enjoyed seeing the maintenance men looking around and some showing my computer their bussiness card or ID.

Steve