remote to colored LED

I’m interested in developing a signal light system where I can be in one room, and by using a small remote transmitter, turn on a small LED signal that is located in another room no further than 30 feet away.

I’m working in a doctors office and would like to use this system as a signal to the staff that I need assistance without picking up the phone, leaving the room, or letting the patient know that I am asking for help. It work best if each of the 3 doctors could use a separte remote to turn on a different color LED at any of the four or five adjacent rooms. The smaller the better.

Any ideas?

Thanks for the input.

These are available off-the-shelf from a variety of distributors:

www.linxtechnologies.com

Look under OEM products.

The units are typically $30-50 each and you should be able to put together a system without any development. All you would need are handheld (or keyfob style) transmitters and function modules. The relay function module can switch up to 4 devices (could be LEDs, buzzers, etc.)