Conversely, the comparator output and the connection to the Arduino’s analog converter (A0) are labeled nodes from the “Output and Labels” menu. The names are significant, including the spaces.

Much to the chagrin of hardware tinkerers, the Raspberry Pi doesn’t have analog inputs on its GPIO pins. Sure, you can blink a LED with just a few console commands, but reading sensors with a… ...

In general, the input impedance of this type of converter is very high (in the several kW range) at lower frequencies (<100 MHz) and rolls off to roughly 200 Ω above 200 MHz differentially.