Using DSO Nano V2 to check for button bouncing

[calculusFTW]

Hi everyone! I have a question. I am working on adding bumper/whisker switches to my robot for collision detection, and I'm currently following the debouncing section of Adafruit's Arduino lesson #5 about using button inputs.

The switch I am using is the Omron Snap Action Switch from SparkFun. I am trying to connect my DSO Nano v2 pocket oscilloscope to see if my switch needs debouncing (i.e. generates spikes in voltage from the internal spring bouncing when the switch is pressed). However, I can't get the correct settings on the oscilloscope so that it reflects the button press, as depicted in the screenshot of the Tektronix oscilloscope screenshot in the tutorial.

Here is a schematic for the switch circuit. I figured out how to get it back to Auto mode (from Scan mode), but the waveform is still just a flat line. Maybe I don't have the scope connected to the circuit correctly?

I have positive connected to the same row of my breadboard as the positive lead from the switch, the jumper wire connected to pin 3, and the negative probe connected to ground (I am assuming the probe wire with the white marks on it is positive)

Can anyone tell me what I am doing wrong? thanks!