I am building an IR remote control using Arduinos. This is going to operate a control panel that is, for reasons too elaborate to mention, already designed and manufactured. That control panel has a bunch of push buttons for controlling different things.
Now, since I do not know how to modify virtually anything on the control panel PCB, my master plan is to connect the IR receiver to the arduino, and use the arduino to send a +5V signal to the output of the push button, in a way bypassing the push button by connecting the arduino signal in parallel.
What is confusing to me, as an absolute novice, is how these things work in actual televisions, audio players, A/Cs etc. How do these devices take signals from either the remote or the manual push buttons on the device themselves? I am looking for any general advice, or perhaps links to web pages, which could throw more light into it.
My eventual aim is to see if there is some way I can send a signal from the Arduino to the uC mounted on my control panel PCB directly, without having to go through the clumsy method of putting wires across push buttons.