Input bouncing with nothing connected

Development Tools IDE 1.x
1

Hi there, new to arduino, and fairly new to electronics. I just recently bought an arduino uno starter kit. As I was going through the beginning examples in "getting started with arduino" When I got to the button press to turn on an LED I noticed that my button presses will jump high to low without pressing any button. I went a step further and removed the button and watched the serial monitor and I can see it going from 1 0 randomly. I've tried this on pins 7, 8, 9. I don't believe this is normal, but as I'm new I don't get it. Any help would be appreciated.

Thanks
Harley

2

The pins will do that with nothing connected, the example should have a pull-down resistor to ground that makes the input low while the button is up, when pressed the 5v should flow through the button making the input high.

3

Thanks,. I tried a different button setup, with the pull down resistor and it seems to be working just fine today. I was having this problem yesterday, thought i had it wired up the same, guess not. Thanks! :smiley: