The wiring challenge from From USB to Field System, virtually. Click one terminal, then another, to run a wire; click a wire to cut it. Build the protected power path, set the buck converter to 5.00V before the ESP32 sees power, complete the sensor wiring, and pass the inspection gates — then power up and watch the CSV stream.
The failure modes are real: raw 12V on the ESP32 is fatal, a missing pull-up makes the DS18B20 read −127, and an unprotected GPIO2 fails Gate 4. Just like the bench.
Follow the reference netlist top to bottom — it mirrors the build order of the unit's lessons.
The trimpot ships at 7.30V. Gate 3 exists for a reason.
Wire colors tell you what a net has become: red is raw 12V, brass is 5V, green is 3V3, navy is ground.
The real thing
This is the same system students build physically in the Grade 9 unit and the same electronics inside the environmental monitoring vessel. The sandbox is for practicing the netlist and the inspection-gate discipline before touching real hardware.