Re: Ability to drive multiple IR transmitters independantly from PC

[Alexis <snoopy@xxxxxxxxxxxxxxxxxxxxx>]

ved_dhuru@xxxxxxxxxxx wrote:
> 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.

Hi again Anand,

Now that is a very interesting solution, that I hadn't considered at
all.  It has the slight downside that global device control (i.e.
switching on or off multiple devices simultaneously) takes a little
longer, but the time taken should be acceptable.

I especially like that it is effectively infinitely expandable, as you
would just need additional switching relays.  Do you happen to know if
there are any schematics detailing how such a switching system might be
implemented online?  I will have a look myself later tonight.

> 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.

This isn't too much of a concern due to them being projectors - they
have two IR reciever windows to allow them to be controlled from
multiple angles, so it's no issue to tape the IR transmitting LED to be
in direct contact with the IR receiving window, and block it out from
transmitting elsewhere.

Thanks again!

Alexis.