I've got an iPod Touch and am trying to create an electrical circuit that, when turned on, will trigger the touch sensor in a specific spot (the spot that whatever component of the circuit provides capacitance is resting on, I guess). For the life of me, I cannot figure out how to trigger a capacitance sensor. I know what it needs; capacitance. Human fingers provide that. I've discovered that the negative side of a battery also works; but how can I control it?