RS-232 control of light bulb

[fro66y]

I am looking for some way to control a light bulb via my PC's serial port. <p>I have found one site (http://www.controlanything.com) that sells a RS-232 relay controller, for $59. Does anyone have other suggestions? <p>Thanks

[sofaspud]

For controlling a 120V incandescent, I can't think of anything to use except a mechanical or solid-state relay. If you can build a circuit and throw together a little bit of code, the $59 controller might be overkill for your application. I'm thinking you only need 2 wires of the RS-232, a signal and a ground.

[wd5gnr]

More overkill for your application, but you could use the controller at [GP3]and a solid state relay or a mechanical relay to do the job. I've used them many times with SSRs but usually we need to control several. The board has libraries that are usable with Visual Basic, Java, C/C++, Linux, or even Active Server Pages.

[MrAl]

Hello there,<p>May i ask why you wish to do this?<p>The reason i ask, is because you'll have to
remember that the computer will have to be
on all the time you wish to control the lamp.<p>Take care,
Al

[Tommy volts]

fro66y,<p>I built an I/O system that plugs into the DB-9 serial port. It controls up to 3 mechanical relays. The code (written in QBASIC) and design I got from an article by Ray Green in N&V.<p>It works great. The total cost was about $5.<p>If youre interested let me know and I will hunt thru my stack and find the date of the N&V article.

[Bob Scott]

How many hobbyists does it take to turn on a light bulb?<p>Bob

[petemig]

Hi Guys,
Any chance of a pointer to the Ray Green article you refer to
Cheers
Peter

[Lin Farquhar]

You really married to the serial port? If not, just use the parallel port. You've got 8 data lines dedicated to going click-clack. Use a ULN2803 darlington driver to pick off the signal and drive a relay.

[jollyrgr]

Want a plug and play solution that is easy to interface and widely supported? Then you need to go with X10. The kit you want to start with is called the "Firecracker 4-Piece Home Control Kit". As I type this the kit sells for $39.99. It includes an RS-232 interface (about the size of a gender changer), a Transceiver (the main device that picks up the RF signal and puts it on the AC line), a lamp module (which can turn the light bulb on, off, or any intensity level in between), and a palm pad controller (hand held remote control independent of the computer). Using the X10 system you can control up to 16 addressable channels of lighting effects.* The number of light bulbs controlled is limited by your pocket book. Most light modules can handle up to 300 watts. If you want to control wall mounted light switches you can get them as well. The X10 devices have a unique feature that will allow you to turn all lights on or off at once. You can start with the kit listed above (it is much cheaper this way) and you will need at least the Transceiver, one lamp module, and the Firecracker computer interface.<p>The best thing about the X10 system is that they provide the basic software for "FREE". They even have voice command software so, as they put it, you can "tell the coffee pot to start brewing and it will!"<p>There are many ways to control lights with computers but the X10 system is one that makes it easy. No complex wiring, no interface cards to install. They even sell screw in lamp modules. Simply put the module into a live socket and screw in a light bulb. How simple does that get? Extra modules are even available at Radio Shack. (Radio Shack tends to be on the expensive side, thought.)<p>If you buy from X10 I strongly suggest that you shop for their "kits". In many cases you can get what you want plus many extras cheaper than buying just the item you wanted. Buying over $50 worth of stuff gets you free shipping. (It is worth buying something extra as you may end up paying as much in shipping as you would have for the extra module.)<p>
*The 16 channels is not "REALLY" true. The X10 system allows you to control 16 devices per "house code". There are 16 house codes which means you can really control up to 256 independent devices. But this means you need a transceiver per house code.

[Tommy volts]

petemig,<p>Are you still interested in RS-232 I/O relay control articles by Ray Green?

[wd5gnr]

Speaking of the Firecracker, if you can get these cheap (they have, at times, given them away for shipping) they make a great interface for the BS2:
http://www.al-williams.com/firecracker.htm