The combination of a Raspberry Pi (4 or 5) and a Raspberry Pi Pico has the potential to replace an entire “equipment park” of measuring devices like V-A-Ω meters, function generators, RF generators, oscilloscopes or transient recorders, as well as frequency counters. One must-have element in nearly all such test equipment is the analog-to-digital converter (ADC). In this article, we look at the process of implementing ADC functionality on “the Pi's” from the Ground up (pun intended).