Visual Alarm

March 29, 2008 4:57 PM

I need to design/buy a visual alarm for use with a PC.

I'm writing a small software application that will be installed in about 200 places. The main task of this application is to monitor a database. When there is an important change in the database, the person closest to the PC needs to interact with the software.

I need a visual alarm because of 2 things I cannot change: the places were these computers are installed must be completely silent and the people working near the PC usually are at least 10 feet away and looking the other way. This means that I cannot use speakers nor headphones to notify the users that they need to check the computer.

Currently, I can only think of building a bright led that I can control via USB. This LED will be placed (using a long cable) where everyone could see it. My software could make the LED blink whenever I wanted to.

I can write the software to control this USB controlled LED and, maybe, I could find someone to design this USB led.

But, before doing that, I just need any ideas or comments you might have about my problem and idea to solve it.

Whatever the solution it must not be expensive (less than 20USD per unit) since we need to buy build at least 200 of them.

Thanks!

posted by edmz to Technology (8 answers total)

can you have it send out a text message or page?
posted by Oktober at 5:23 PM on March 29, 2008

Oktober,

thanks for answering.

Sadly, no sms. At least in Mexico they are not reliable and could take minutes to arrive if ever. Plus, they cost money to send (10 to 20cents per message). Imagine 20 sms per day times 200 thats a lot of money for something that might be cheaper.

Prompt response to the visual alarm is VERY important.
posted by edmz at 6:29 PM on March 29, 2008

Low tech solution: when they're not at the PC, have the screen be black. The alarm can consist of the full screen flashing rapidly. Install a mirror to make it more visible from their positions.
posted by dmd at 7:22 PM on March 29, 2008

You could get one of these. That site seems to have a lot of USB devices that might work for a visual alarm, but that seems like one of the more eye catching ones.
posted by slavlin at 8:43 PM on March 29, 2008

dmd,

we have tried that before, but in some of the places where the PCs are installed there is a wall between the people and the computers. That is why the led light go all the way to where the people are.

I know, the scenario is quite restrictive, I wish it was different.

slavlin,

the usb lamp that you suggest is close to what I need except for the fact that it is always on. There needs to be some logic between the usb lamp and the pc that allows the software to turn it off. USB ports, I've been told, are always on, so there is no way to turn the light off. The way its done, is to send some data to the USB port and have the device (the lamp in this case) turn itself off.
posted by edmz at 9:47 PM on March 29, 2008

See people, now this is why we still need serial & parallel ports on computers. It'd be a doddle using either of those...

So, why not use a USB serial or parallel adaptor and scour Google for one of the many different ways of driving an LED or relay from the port?
posted by Pinback at 10:20 PM on March 29, 2008

(Alternately, getting one of those USB rocket launcher toys and writing an app to fire missiles at their eyes until they a) go blind or b) respond may be more fun ;-)
posted by Pinback at 10:26 PM on March 29, 2008

How about something like the Hudson Orb? It's used to monitor build failures in software projects. Kohsuke's page links to all the information you might need to build one yourself, plus the software he used is open source and could be modified to fit your needs.
posted by tomwheeler at 10:11 AM on March 30, 2008