Computer control of an audio multiplexor

That's pretty well "impossible" to do without something like a KVM switch (with audio).

I assume you really want to select one of the radio outputs to go to the sound card. Multiplexing is a different technology en.wikipedia.org/wiki/Multiplexing

It all depends on how you define cheap and easy.

If you are handy with a soldering iron and writing simple programs then using the parallel port to control 6 DPST relays would do what you need. With a well supplied junk box you could do it for under $20.

Here are some links:

ourworld.compuserve.com/homepages/Bill_Bowden/page6.htm

Even though I could easily do the above I would opt for the eBay route. What you are looking for is an audio matrix switch with RS232 control. Since you have 6 inputs and only one output then anything larger than a

6x1 switch.

Here are links to VERY NICE AutoPatch half-y units:

cgi.ebay.com/autopatch-half-y-matrix-composite-switcher-with-audio_W0QQitemZ180187334290 cgi.ebay.com/AutoPatch-Half-Y-8x4-Stereo-Audio-Video-Matrix-Switcher_W0QQitemZ320188063634

For my money I would use one of these to do the job. I have done several AutoPatch installations and their equipment is top quality. While you don't need 1/2 of what these units will do the price is right! Notice that the terminals on the first listing are removable screw type while the second listing has RCA terminals which might be handier.

Control software and protocol can be found: autopatch.com/index.php?object=286 autopatch.com/pdfs/bcs/bcs_serial_control_protocol.pdf

Marc Hult (who posts here regularly) has some Ivie 784PW 8x4 audio matrix mixers in his porch sale for $70. Here is a link:

If you like buying new then these are some audio only switches that could do the job:

Other options include using RS232 controlled relay cards like these:

Since all the controlled relays are local X-10 is not an appropriate technology. When used properly X-10 can be quite reliable.

Good luck with your project. If you need more information please reply with a bit better description of what types of radios, type of computer and a better description of the total project.

In my work, I do that sort of thing all the time. I can buy switching instruments from National Instruments to implement any kind of switching matrix.

But, using industrial equipment, the whole thing would cost thousands of dollars.

I'd like a way to do it at home for reasonable amounts of money. And, especially, make it controllable from the PC.

I find musician's equipment like this:

But, nothing to just do the switching.

You've been very helpful.

The pencomdesign.com link was good. In my googling, I hadn't run across that one. I believe it might meet my requirements.

This project would have nothing to do with X10, it would also have nothing to do with KVM switches as someone ignorantly suggested.

Actually quite easy.

6 channel 8 channel

Just have your control program send the appropriate commands via the serial port.

I have no idea of quality or price. I suspect that there are other complete solutions like this or similar items can be created to be controlled by a digital output device (available to be controlled by various means).

I didn't mean for you to take me literally. "Something like" a KVM switch shouldn't infer I was suggesting he use one. He clearly wants to control multiple sound sources. Using "something like" a KVM switch (a device which directs inputs from several computers to one keyboard/mouse/monitor) would probably do the trick. Several other suggestions have been offered (including a couple from you). Nice to see so many put so much more thought (and less animus) into their responses.

All the boards I ran across had SPDT relays which will only handle a mono signal. For stereo you will have to replace the relays with DPST or DPDT ones, use the existing relays to control outboard DPST or DPDT relays or buy two boards.

The AutoPatch unit is a STEAL at $176 delivered, Hult's unit is even a better deal. I realize these units do more than you want but I think they are a better value since they are ready to go in a enclosure and connectorized.

The Phonic HelixBoard12 12-Channel USB Mixer is quite cool! I have a Phonic PAA2 which is very handy, amazing for the price but not the best quality. It went back twice under warranty and still is not 100%.

Also consider that you might want to use multiple sound card inputs. It's trivially easy to add sound ports to a computer using USB devices. I've got a home audio setup that has four such USB devices powering audio zones. I use two of the line-in inputs to re-route other external signals. The re-routing is sometimes a bit tricky as it involves redigitizing the signals. On an 'old school' sound card it was possible to keep the analog signal and simply re-route it out. But as soon as you get into moving the signals off one device and out another it's requires the CPU be involved to process it.

The upside to multiple inputs is the ability to record from them all simultaneously, provided you've got enough CPU and storage.

Just a thought to consider.

-Bill Kearney

Yes, many folks have done. What exactly is meant by "switched according to the commands from my pc" ?

Are these commands be sent manually from the command-line ( aka "DOS") interface?

Or do they need to be integrated into existing or planned Home Automation (HA) software? Do you also need that software? Or are you going to write it?

If you use HomeSeer, or most any other mature HA software, there are typically numerous solutions including user-contributed scripts to do similar things.

But if you first select the hardware you may find that you can't use it for lack of appropriate software. If you first select the software, and explore what hardware it works with, you will almost certainly find several different hardware components/solutions to complete the project.

I have a write up about the many uses of audio in HA here:

\audio.htm

Typical uses of audio in "home automation" include:

Voice control of home automation system Intercom Background music Paging Intruder alerts Door answering real time actual, and recorded including by fido ("Rex") Telephone Occupancy and device monitoring (washing machine, external sounds etc). Home Theatre

As Bill Kearney points out, I have some Ivie audio auto-matrix mixers with preamps for sale that are suitable for all the uses listed here.

\porch_sale.htm

Simple command-line ASCII instructions and a Windows program are available free from

to control them.

... Marc Marc_F_Hult

"Joe User" a écrit dans le message de news: snipped-for-privacy@random43332.fictitious.us...

the use of a parallel port would be a lot better then a serial port..

just by sending a special character to the parallel port would trig one of the 8 bit of the port,this would in turn control some small relay that could switch an audio selector, noting too complicated to do...

the worst part would be to make the program that would send the good character to the printer port..(for me)

I have seen kits to do this, and they are a reasonable approach. The drawbacks are that I lose the use of the parallel port, and usually I would have to do some soldering and layout. I would rather just buy something, patch in the lines, write some scripts, and use it.

I may wind up using a parallel port decoder, or maybe two or three sound cards.

Thanks to everyone who commented.

Then I don't see the obstacle. This could 'easily, simply and inexpensively' be done with a used National Instruments PIO card and some relays. I have some like-new NI 24- and 96-bit PIO cards for nickels on the dollar at

... Marc Marc_F_Hult