Every trace is a KCL equation
Kirchhoff's laws are not exam furniture — they are what the copper on a real board does all day. In this capstone you analyze a two-branch LED circuit by hand, then build it in PCB Studio and find your node equations living inside the generated schematic and the routed traces.
- On paper: the 3.3 V rail feeds two parallel branches, each an LED (2.0 V drop) in series with a 330 Ω resistor, plus nothing else. Label the rail node and ground, then use KCL at the rail node to find the total current the rail supplies. (Each branch: i = (3.3 − 2.0)/330 ≈ 3.9 mA.)
- Write the KVL equation around one branch's loop and verify it balances with your numbers. Then run the Σp = 0 audit across the rail and both branches.
- Open PCB Studio: add the Pico 2 W, two 5 mm LEDs on separate GPIOs, and a pushbutton. Generate the schematic.
- Play Kirchhoff on the result: identify the ground net and count how many branches meet it — that count is a KCL statement. Trace one LED's loop from its GPIO through the LED and resistor back to ground; that path is a KVL statement.
- Run "Generate + PCB layout" and study the routed board: the GND net's traces form the node your equation in task 1 described. Every trace on every board you will ever design is carrying out these two laws — the Studio's validator is checking a subset of them before the board exists.