I have the following setup:

Now, basically, I'm just going to want to use this switch as a simple on or off. It's an SPST. I've got software running that sets up GPIO_13 as an input pin, and continually reads from it. (This is no ways reflects the actual GPIO layout on the Pi, it was just for demonstration).

Now, measuring from the input terminal of the switch to circuit ground always gives 3.3 volts, as it should. And, when the switch is ON, measuring from the output pin to ground also gives 3.3 volts, and the software reports TRUE.

Now, turn the switch to OFF, and measuring between the output terminal of the switch and ground gives about 0.85 volts. Steady. The software rapidly flickers between TRUE and FALSE.

If I disconnect the output terminal of the switch so that it's not connected to the input pin, I measure 3.3 volts on the input terminal and 0 volts on the output termainal while OFF. Good.

So, what's making that 0.85 volts pop up? Is there somehow a positive voltage ON the input pin?

Any guidance welcome,

• Chase

I'm trying to use a switch to to provide input to software running on the Raspberry Pi. I have software running right now that continually reads the input pin and prints the result. Problem is, even when nothing is connected to it, the voltage reading from the input pin to circuit ground reads about 0.9V. The software rapidly flickers between TRUE and FALSE.

Is this a software issue? If not, how can I avoid this?

Thanks for any advice,

• Chase