Original BrickPi Bookreader
In this project we make an ebook reading robot with the BrickPi.
10. Building the Robotic Arm
Probably the hardest part of this build is to get a robotic arm to turn the pages on a capacitive touch screen.
We used the foam that comes when you get some IC’s.
Cut a small piece for using as the stylus.
After testing a couple of materials, the best candidate for a capacitive stylus was a bit of antistatic foam (the one that comes with IC’s from Mouser!). You can also use normal kitchen sponge, but it has to be moist, so just put a few drops of water on it. We found performance improved with a conductive wire with the foam and wrap it around the arm. We also found that it helped to connect a 47 nF capacitor between the foam and the ground on the BrickPi.
You can even use a moist kitchen sponge.
Attach the piece of foam on an arm stretching out from the motor and connect the capacitor to it. We also attached a small LEGO block, tilted, which helps making an easy contact with the touch screen.
Place the tablet in a proper position so that the arm is able to move up and down properly and turn the pages on the screen.
