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Your first board

This lesson builds a small board from one sentence: four LEDs that chase each other, powered from USB-C. It takes about fifteen minutes, most of it waiting for the router, and costs a few cents of AI time with Claude.

Before you start

  • WholeBoard is installed and python -m wholeboard.doctor shows KiCad, TraceMaker and ngspice as found (Install and check the tools).
  • An AI is set in Settings → AI (an Anthropic key, an OpenAI or xAI key, or a local server).

1. Start WholeBoard and take the tour

Run ./run.sh (run.bat on Windows). The browser opens at http://127.0.0.1:8770/.

Press Take a tour in the top bar. It walks through a normal workflow and highlights each part of the page: the chat, the step bar, the visuals, the quote and the enclosure. It is the quickest way to learn where things are.

2. Describe the board

Press + New board and type:

Four LEDs that light one after another, about twice a second, powered from USB-C. Small, two layers.

The designer reads the request and asks only what changes the design. Expect a question or two, such as whether you want an enclosure and whether the board should screw into it. Answer in the chat; the buttons under a question are suggestions, and you can type anything.

3. Watch the steps

The step bar along the top fills in as the build goes. Click any step to see its visual:

Step What to look at
Parts & architecture The designer starts from the usb_c_power and led_indicator building blocks and searches JLCPCB for the rest
Design check Every footprint exists, every pad is in a net, every part is in stock
Schematic & ERC One sheet per block; KiCad's electrical rules check
Simulation ngspice runs the circuit: the 5 V rail, each LED's current, the timing
Placement and routing TraceMaker's live viewer, then the routed board
DRC & copper pour KiCad's DRC against JLCPCB's rules, trace heating and voltage drop
3D views & fab files Renders, Gerbers, BOM and CPL
JLCPCB quote Board, assembly, parts and shipping, itemised

If a step fails, the result goes back to the designer, which fixes the design and builds again. You will see it say what went wrong and what it changed.

4. Look at the simulation on the board

Click the Simulation step. Once the board is routed it opens the Sim Lab: the finished board in 3D with current flowing along the tracks and each LED lit as brightly as its simulated current. Click a risk in the list (an LED near its current limit, say) to fly to it, and move the resistor slider: ngspice runs again in under a second. The design is not changed; ask the designer in the chat to make a change stick.

5. Read the quote

The quote itemises the bare board, assembly, every part at today's LCSC price, and shipping. Look for:

  • Cheaper parts: drop-in replacements that avoid JLCPCB's extended-part fee. Tick them to apply.
  • Panel options: for a board this small, a panel is often cheaper.
  • Other fabs: OSH Park, PCBWay and Aisler for comparison.

6. The enclosure

Once the board is clean and quoted, the designer plans a box and FreeCAD builds it. The step shows a 3D preview, any collisions between parts and the box, how warm the inside gets, and downloads: base.stl and lid.stl for printing, STEP files and an editable FreeCAD macro.

7. Change something

Type in the chat:

Make the LEDs blink faster and use green ones.

The designer edits the design and builds a new revision. History lists every revision with what changed; tick two to compare them.

What next