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Author Topic: Digital I/O Router/switch - What options are available?  (Read 681 times)
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Wellington, New Zealand
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Hi...

Have been searching online but could not find anything except networking equipment.

Is there some sort of integrated circuit available that can do routing / switching of IO(Input / Output) lines?

Example, if you have 5 input and output lines I would like to be able to change how input pins are forwarded
to the output pin. A real world example of this would be like the old phone exchanges where the operators routed incoming
callers lines to specific receiver lines.

I know automated phone exchanges can do this somehow.

Any suggestions or pointing in the right direction would be appreciated.

Thanks.
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Multiplexer:

http://www.gammon.com.au/forum/?id=11976
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That's exactly what I am after... Thanks for that Nick.

Now I have a name I can do some reading up on... smiley-wink
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A real world example of this would be like the old phone exchanges
A more relevant example is the analog inputs of your Arduino.  There is only one A/D in the chip.  The 6 analog inputs are connected to an Analog-Multiplexer (also on chip), which gives multiple analog inputs.
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I see. I was wondering about that.. So a port extender is then the same thing,right?
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It's a bit different because the multiplexer handles analog inputs, but a port extender basically just outputs low or high. I suppose it depends on your definition of those words.
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It's a bit different because the multiplexer handles analog inputs, but a port extender basically just outputs low or high. I suppose it depends on your definition of those words.

Thanks for pointing that out... A multiplexer will actually be more useful because like the Arduino analog pins, you can also make them act like Digital pins.
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nr Bundaberg, Australia
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Quote
if you have 5 input and output lines I would like to be able to change how input pins are forwarded
to the output pin.
This is more an app for a crosspoint switch, you can get them in 8x8, 8x16 etc. An 8x8 is basically 8 8-way MUXes in a single chip.

_____
Rob
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Rob Gray aka the GRAYnomad www.robgray.com

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This is more an app for a crosspoint switch, you can get them in 8x8, 8x16 etc. An 8x8 is basically 8 8-way MUXes in a single chip.

Hi Rob... Do you have an example of an IC that I can go an look-up?
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nr Bundaberg, Australia
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There aren't that many I think, I have data sheets for these ones

AD75019
CD22M3494
M22100
MAX4359-MAX4456

EDIT: Crosspoint switches are mostly used in telecoms and are analogue but still switch digital. If you have a digital application one way to do it is to use a SRAM chip and program the bits to provide the transfer function you want, I've never done it but I would think it would work. Also if the speeds are real fast you could dedicate a CPU to the job, read 8 bits, index into a table, write 8 bits.

_____
Rob
« Last Edit: July 08, 2013, 04:47:33 am by Graynomad » Logged

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I personally used a 22100 in a matrix scanned keyboard solution to "simulate" key-presses... though I think that part is considered quite obsolete now.
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