Is there a way to control a button? Say if i have a recording module where if u press a button it plays a 20 second recording. Is there a way to have arduino control the actual button press? For example in simplest form:
if something happens (sensor)
do this (press button so it playes the recording)
how do i wire up this to arduino. It will not be used with the recording modules thats just an example.
thanks,
Roman
Without knowing how the button is connected, it is difficult to to answer your question.
You could use a servo.
It would probably be easier to put a relay (or a switch IC such as cd4066) in parallel with the physical switch. This way you can use Arduino to control the relay or IC switch.
Anyway, it does require modification to your recording module but it should be pretty straight forward.
You could analyse what circuitry is connected to the button and replicate that. Probably too hard.
The easy was is as has been suggested, add a relay/FET/4066/etc across the switch and control that. This will be neat but means hacking your module.
The servo idea will look like hell but at least you won't void your module warrantee 
Rob