06Portfolio
A Pico 2 W controller board
The target board for the Golf IV electronics: a Raspberry Pi Pico 2 W instead of a Pi Zero with add-on modules, a power stage that survives automotive transients, and every output on one board. The schematic and PCB are generated by scripts.
By the numbers
- Board size
- 140 × 100 mm
- Converter input rating
- 60 V
- DRC errors
- 0
Problem
Today’s setup in the car is a Pi Zero 2 W plus a handful of modules on wires: a UPS, an ADC, ULN drivers and a separate 12 V charger. It works, but there are many connections, and nothing protects it from transients on the car’s supply. The move to target hardware had to be planned so that nothing would need redoing later.
Approach
The Pico 2 W (RP2350 + CYW43439) does everything on its own, and the board keeps an unpopulated UART header for a Pi Zero as plan B. The power path: a fuse, reverse-polarity protection on a P-MOSFET, a TVS diode for load dump and two TPS54360 converters rated for 60 V input — one for the logic and one for the LED strip, so the strip cannot drag the logic down. Lock inputs get a divider with an RC filter (τ ≈ 1 ms), windows and mirrors are driven through ULN2803/ULN2003 in parallel with the factory buttons, and the central lock through PC817 optocouplers. The schematic, placement and routing (Freerouting) are generated by Python scripts — a spec change means re-running them, not clicking through the editor again.
Outcome
Revision 0.1: a 140 × 100 mm two-layer board, ERC and DRC clean, with a full set of manufacturing files — Gerbers, BOM, pick-and-place and a STEP model for the enclosure design. Before ordering, a prototype has to confirm three things: Bluetooth in two roles at once, TLS 1.3 over the LTE modem, and the WireLink channel on mbedTLS matching the test vectors.