Arduino pins always read high

Development Tools IDE 1.x
1

Hello,
I have been getting input from my raspberry pi's GPIO pins on my Arduino, and I'm not sure if this started before or after I started doing this but now if I plug a jumper wire into a pin on my Arduino and read from it it always returns high, even if the jumper wire isn't connected to something on the other side.

I really hope I haven't broken my Arduino.

Any help is appreciated thank you.

2

An open input pin without a pull-up or pull-down resistor will read randomly HIGH or LOW. In your case it seems to be HIGH. Connect a pull-down resistor (1K Ohm) between the pin and Ground if you want the open pin to read LOW.

3

Thank you so much. I drew a blank on that one. Grounding the pins worked perfectly.

You help is much appretiated