20260625 - Video with Frank Delporte
Testing a Java I/O library properly means testing it on real hardware. For Pi4J that means running the smoke test: a setup with two BMP/BME280 sensors and a tangle of GPIO-to-GPIO jumper wires that has to be rebuilt by hand every session. This video tells the story of board number 0001: turning that breadboard setup into a proper PCB.
It covers why a fixed board makes the smoke test fast and repeatable, designing the schematic and layout in EasyEDA Pro (with help from a CoderDojo coach), what ended up on the board (40-pin GPIO header, LEDs grouped per GPIO test, I2C and SPI sensor connectors, and extra headers for a logic analyser), ordering at JLCPCB, and the first successful test run on a Raspberry Pi 5.