Cylindric:
johnwasser:
If you put the switches to the Vcc side you have to use an external pull-down resistor. If you put the switches to ground you can use the internal pull-up resistor. Your R1 and R4 are not needed. If you use ground instead of +5 your R2 and R3 are also not needed.So just to check, you basically mean connect PinA to the switch, and the switch to GND, and not need any external pull resistors?
Correct. Enable the internal pull-up and the switch will read HIGH when open (because of the internal pull-up) and LOW when closed (because of the connection to ground through the switch).
Many people seem like the HIGH means CLOSED, LOW means OPEN they get when they use an external pull-down and s switch to +5 but the software can be written either way and the hardware is less complicated and expensive when you use the internal pull-up.