A multimeter gives you one number; an oscilloscope shows you what the voltage is actually doing, moment by moment. This virtual scope carries the five signals inside your ESP32 water monitor — the 5V rail from the buck converter, the turbidity and EC sensors, the DS18B20's digital temperature bus, and the pump's PWM — with the real controls: timebase, volts per division, and a trigger.
Never used a scope? Just follow the built-in tutorial. It starts with the steady 5V rail and ends with you setting the pump's speed from the average-voltage readout — and every term gets explained the first time it appears.
2 ms/div1 V/divTRIG ▲ 1.6VRUN
STEP 1
Signal
RIPPLE
FREQ
Timebase
Vertical
Trigger
LVL
Controls
Measurements
Vpp —
Vavg —
Freq —
Duty —
What it is —
Why it matters —
Challenges
Zoom the 5V rail to 0.5 V/div and read the ripple's size from Vpp. Could a multimeter have shown you that?
Crank the turbidity NOISE up high and watch Vavg. Why does the average stay useful while every single reading jumps? (This is why your code averages.)
Freeze the Temp bus with STOP and count the pulses in one burst. Why can a scope show this conversation when a multimeter can't?
Make the pump's Vavg exactly 1.65V. What duty cycle did it take — and why does pump speed follow the average instead of the peaks?
Where this leads
Every signal here is one you'll meet on the bench: the rail is the buck-converter output you verify in Lesson 4 of the field-system unit, the Temp bus is the DS18B20 from Lesson 6, the EC probe is Lesson 7, and the turbidity fuzz explains why your readings refuse to sit still in Lesson 12 — the noise was always there; the multimeter just averaged it away. The PWM view is the pump speed control from the vessel's science station.