Custom electronics: PCB design and prototypes

01What I do

What I do

1. 01

   PCB design in KiCad

   I draw the schematic and design the board in KiCad. The Pico 2 W board was generated by Python scripts, so a change in the requirements meant re-running a script rather than redrawing the design. It passed KiCad's error checks with no issues and has the full set of files needed to order the board.

2. 02

   Power from a car's electrical system

   A device powered from a car's electrical system has to survive voltage spikes and a wire connected the wrong way round, so I design in protection against both. On the Pico 2 W board the LED strip has its own power supply, so its current draw can't disrupt the rest of the circuit.

3. 03

   Software for Raspberry Pi

   On Raspberry Pi I write C++ programs that respond to what's happening in the car and connect to an app on the phone. In led-auto, opening a door switches on the entry light, and locking the car after getting out switches it off. I check the logic automatically in every situation the device can end up in, and I test the device itself on the bench with real signals from the lock before it goes into the car.

4. 04

   Enclosures for 3D printing

   I design enclosures parametrically in CadQuery, so changing a dimension means changing a parameter, not redrawing the model. In the Pi Zero 2 W enclosure with an LTE modem I fitted four boards and planned openings in the walls for the antennas and the wires from the car.

5. 05

   Hardware together with the app

   When one person builds both the hardware and the app, the communication between them is designed once, on both sides at the same time, with no need to agree it between two contractors. The led-auto device connects to the WireAmbi app over an encrypted connection, and I wrote both ends of it myself.

02Who it's for

Who it's for

For people and businesses who need a prototype board or a small Raspberry Pi device, especially when an app is needed for it too. I take on smaller projects, and my work ends at the prototype, without production.

03Related projects

Related projects

• 05

  Electronics · 2026 · Own project · Golf IV

  led-auto — a Bluetooth gateway for a Golf IV

  A gateway on a Raspberry Pi Zero 2 W in my Golf IV: it switches on the entry light when a door opens and controls the LED strip, and it talks to the phone over an encrypted channel. It works in the car with the Android Auto panel. I checked its logic automatically in every possible state.

  Rules checked in every state

  18

  Automated tests

  154

  C++Raspberry PiBluetooth LECryptography+2

• 06

  Electronics · 2026 · Own project · Golf IV

  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.

  Board size

  140 × 100 mm

  Converter maximum input voltage

  60 V

  KiCadPCBRaspberry Pi PicoPython+2

• 07

  3D printing · 2026 · Own project · Golf IV

  An enclosure for a Pi Zero 2 W with an LTE modem

  A 3D-printable enclosure for four boards: a Pi Zero 2 W, a backup power supply (UPS), a terminal block and a 4G modem. Every dimension is a parameter in a script. The design is ready to print but has not been printed yet.

  Outer dimensions

  74 × 92 × 46 mm

  Boards inside

  4

  CadQueryBlender3D printingRaspberry Pi+1

04Frequently asked questions

Frequently asked questions