Re: Ability to drive multiple IR transmitters independantly from PC

[ved_dhuru@xxxxxxxxxxx]

Ok, here's another approach; a hybrid of dave's solution and mine.

Use my solution (above) to select the channel, and the particular relay
drives the USB IR's IR LED. You would then need only 1 USB IR. You
would have to hack it to get to the IR LED output.

On the PC, you'd need two commnads to be sent; channel select and
on/off.

Also, you would have 1 transmitter per display, so the concerns that
Dave mentioned would come into play unless you shield each LED and
leave a very narrow aperture, and then place it in close proximity of
the individual displays. I have had excellent results using black
heat-shrnkable tubing to achieve this.

Regards,

Anand


Dave Houston wrote:
> Alexis <snoopy@xxxxxxxxxxxxxxxxxxxxx> wrote:
>
> >Hey guys,
> >
> >I've got a situation where there's a number of identical displays in the
> >same area, and need to be able to switch them on and off individually
> >from a PC.
> >
> >Currently there are 10 identical displays, which accept commands from a
> >remote control to switch on and off (discrete commands for each action).
> >I want something that I can connect up to a PC and will allow me to
> >switch on and off each display individually.
> >
> >Obviously this means that there has to be ten IR transmitters, each
> >placed next to the sensor of the relevant display, and each of which can
> >be driven independantly (i.e. sending the same signal to all 10 will
> >result in all ten displays switching on/off - not the desired
> >functionality).
> >
> >Whats more, the solution needs to be expandable to deal with up to
> >twenty such identical displays, all of which need to be individually
> >controlled.
> >
> >I had considered using single USB IR transmitters, plugged into a USB
> >hub and then into the PC, but I doubt a single PC would be able to drive
> >20 such devices concurrently, not least of all because it would run out
> >of COM ports. So I'm looking for something which is designed to allow
> >control of multiple transmitters independantly.
> >
> >Is there anything like this on the market? Ideally I'd like it to have
> >an API so that I can interface into it from my own code, but that's not
> >an essential requirement.
> >
> >Any help appreciated!
>
> What's the distance from PC to displays?
>
> USB has limited distance on the USB cable length. However, you could use an
> external IR emitter with a long lead. This may require disabling the
> internal emitter to prevent it from affecting multiple receivers.
>
> The question is whether the PC can distinguish between multiple USB IR
> modules.
>
> I would ask the designer of USB-UIRT if you can use multiples. If so there
> is an API for these devices and they are reasonably priced.
>
>      http://www.usbuirt.com/
>
> Is it possible to change the code that each display responds to? If so, you
> only need one IR unit.
>
> http://davehouston.net
> http://tech.groups.yahoo.com/group/roZetta/
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