Connceting digital projector with analog control box

Hello

I work at a movie theater that recently replaced our old 35-mm film projector with a new digital one. With the old 35-mm projector you placed some tape on the film when you wanted, for example, switch the light on or off and the projector sent a signal to a control box that did what you wished. The problem is that we don't have any way of interfacing the new projector with the. old system. A couple of days ago it hit me, couldn't you use an arduino-card as an adapter? The projector has a control-program that can control other equipment via an serial-port and, as far as I know, the old projector sent simple electronic signal, think light switch, to control lights and curtain.
I don't now much, if anything, about electronics and at the moment I can't tell what kind of voltage or amp the old control box wants but, if we (can) ignore that fact for at moment, is what I wish to do even possible? The software part that needs to be written I can/should be able to figure out, but I need some help with the hardware, not so much piece them together as figuring out what to buy....

Hope some of you wizards can help me with this!

but, if we (can) ignore that fact for at moment

I don't think we can.

is what I wish to do even possible?

Maybe. Maybe not. Links to the hardware that you want to interface with would be essential to answering that question.

PaulS:

but, if we (can) ignore that fact for at moment

I don't think we can.

well, maybe I was hoping for to much...

is what I wish to do even possible?

Maybe. Maybe not. Links to the hardware that you want to interface with would be essential to answering that question.

As for the hardware, the new projector is a Dolby 3D projector connected
to a DSS200 http://www.dolby.com/us/en/professional/hardware/cinema/cinema-servers/dss200.html which has a RS-232 connector on the back that I'm hoping I could use.
As for the old control box, I'll have stop by at work to see if there is any kind of markings on it...

Do you have a way to 'stick some tape' on a digital movie and get the serial port to report it?

dxw00d:
Do you have a way to 'stick some tape' on a digital movie and get the serial port to report it?

Yes, the software running on the server controlling the projector has what is called cues, with this you can send signal for setting such things as volume level, audio channel, video format and most interesting in this case, cues for light and (I think) curtains. We are currently using this to control the audio system, which is quite a bit newer then the projector :stuck_out_tongue: