Arduino based projects are quite complicated and is no cake walk for beginners in this field. Interfacing a tablet with the microcontroller is a daunting task. Let see how its done here.
The primary focus should be on using the appropriate drivers for the tablet. This makes it a USB host. As seen in the video, light can be a medium of communication between the tablet and the microcontroller. A photo diode or photoresistor is what is needed here and this should be pressed against the screen.
Building a touch sensing capability can help in providing communication between the microcontroller and the tablet. Capacitive touch screens function by sensing the capacitance changes on the screen. In this case, a large conductive brass plate is used to simulate touch. The surface area of the conductor used here to simulate the touch sould be large.
Testing can be done by touching the scrren with a wire and holding the other end. This may not work. This is made to work by sticking a piece of aluminum foil on to the screen and connecting the free end to the pin that is available on the arduino. The video shows the working of the capacitive touch screen. The setup is quite fragile and a little more circuitry could improve its reliability. Thus the capacitive touch screen is done.
