06Portfolio
A Pico 2 W controller board
A board design (revision 0.1, not yet ordered) to replace the Pi Zero and its wired-up modules in my Golf IV. Everything fits on one board with a Raspberry Pi Pico 2 W, and the power supply is protected against voltage spikes in the car. The schematic and PCB are generated by scripts.
By the numbers
- Board size
- 140 × 100 mm
- Converter maximum input voltage
- 60 V
- Errors in automated design checks
- 0
Problem
Today’s setup in the car is a Pi Zero 2 W plus a handful of modules wired together: a backup power supply, a measurement converter, output drivers and a separate 12 V charger. It works, but there are a lot of connections, and nothing protects it from voltage spikes in the car’s wiring. The final board had to be designed so that nothing would need redoing later.
Approach
The Pico 2 W has built-in Wi-Fi and Bluetooth, so it does everything on its own. Even so, I left an unpopulated header for a Pi Zero on the board as plan B. Power from the car goes through a fuse, reverse-polarity protection and voltage-spike protection, then into two separate converters with plenty of voltage headroom: one for the electronics and one for the LED strip, so the strip cannot disturb the rest. The lock signals are filtered for interference. The board works the windows and mirrors in parallel with the factory buttons, and the central lock through optocouplers that keep it electrically isolated from the board. The schematic, part placement and tracks are generated by Python scripts, so a change in the spec means re-running a script, not manual work in the editor.
Outcome
Revision 0.1 has a full set of manufacturing files: the 140 × 100 mm two-layer board passes the automated schematic and layout checks with no errors, and its 3D model will feed the enclosure design. I have not ordered the board yet. Before ordering, a prototype has to confirm that the Pico can handle Bluetooth in two roles at once, an encrypted connection over the LTE modem and the WireLink channel.