USB Device

[neptunedrew]

Apologies if this is posted in the wrong spot...

I have an idea for something and wanted to see if you guys could point me in the right direction.
I want to build a device that would simply turn something on and off through the USB of my computer. For example, let's say I have a light hooked up to a power supply and the switch is controlled by this USB device. I'd like to be able to switch this light on and off remotely through a website.

I'm not looking for information on the website, that I can handle. I'm just trying to figure out where to go to purchase a switch as I described. Not sure if this makes sense but what the heck...

Drew

 

[(*steve*)]

Do you mean something like this?

 

[TedA]

Drew,

All of the data acquisition hardware vendors make digital output modules for USB. The one cited by Steve is an example. One of these modules would minimize the hardware work you would have to do.

Take a look at the products offered by FTDI. They sell modules, adapter cables and chips for USB interface. They have drivers, and some degree of support for users. One of their offerings has 4 relay outputs: P/N DLP-IOR4.

http://www.ftdichip.com/

A couple of less expensive solutions would involve adding a relay, or other switch for your light, to a device that provides just a logic level signal. If you can do that, and create the necessary software, you might try:

Moderately easy and moderately inexpensive: A USB to RS-232 serial adaptor cable. There are several RS-232 control signals that a program may set high or low, as desired. Off the shelf drivers come with the adaptor to make it look like a standard COM: port to the software. These can be even be found in local computer and office supply stores/shops.

You might manage to make a USB to Centronics parallel port adaptor work, but the software side is likely to be more difficult. The ouptuts on this one are handy TTL levels, and there are more of them than there are on the RS-232 adaptor. But, depending on the USB adaptor and the operating system and drivers, it may be hard to control the outputs from your software. I guess if you can make your relay adaptor a slightly more complex, you could have it latch a data bit each time a character is received at the parallel port.

If you can figure out how to do it, the $4.30 US Texas Instruments MSP-EXP430G2 module has the hardware you need, but the necessary software may be a bit difficult.

Ted

 

[donkey]

is it for small objects or is this to turn things connected to mains power?
the dvices are all out there just some of the ones described are not meant for, nor recommended on mains.
I have intentions of using an eee pc one day to automate a few things in my "workshop" so please let me know what you find and how easy it is to use. (by workshop I mean the tin shed with NO tools of importance as yet)

 

[neptunedrew]

Thanks for all the advice guys and yes, you guys nailed exactly what I am after.

I'll have to go through and probably buy some of these and test them out. Then I'll need to build the webcam and operation of the light using flash. I'll probably reply back to this thread in 2014 when I get it to work.

Thanks.