I am using an Arduino Uno and would like to simulate a capacitive tap with zero human contact on my iPhone 5 screen.
What seems to work right now is putting a coin on the screen and connecting the coin to a power source (such as Digital I/O Pin) and when voltage is sent to the coin it triggers a "tap" on the screen. Is this safe? Is there a better way to do this? I just read somewhere else that any grounded conductive object should work. Is it better to ground the coin or to connect it to a power source? Also, how can I stop sending current to/grounding the coin so the simulated touch is stopped. Right now, I can't get the arduino to stop "touching" the screen.
Best Answer
When I used to work in touchscreen development, we had a couple of methods to achieve exactly that. The first was to interrupt the connection to ground with a miniaturised relay. The shorter connection between the relay and the "finger" the better. The other method was to use an RC servo, which simulated a mechanical finger. Both worked, but obviously the relay was faster acting.