I have a project where I am using two Arduinos. One for a WiShield and one for other stuff like an LCD screen. I have a button I am debouncing attached to the WiShield Arduino that works fine. I need to read the button state from the second Arduino. When I do so, I get odd readings, like it switching from 0 to 1 or 1 to 0 without the button being pressed. I have the button wired as in the image.
Am I getting odd readings because I don't have +5 V coming from the second Arduino? How can I correct this or how should I have this wired up?