A hands-on exploration of running Java on two Banana Pi boards — the ARM-based BPI-M4 Zero and the RISC-V BPI-F3. Java 25 (Zulu) installs and runs fine on the ARM board via SDKMAN, while the RISC-V board requires apt-installed OpenJDK. Getting Pi4J GPIO working on the BPI-M4 Zero required significant debugging: the board uses an Allwinner H618 SoC with a different GPIO numbering scheme than Raspberry Pi, requiring manual calculation of gpiochip1 line offsets (e.g., PI15 = 8×32+15 = 271). After resolving these issues, an RGB LED was successfully blinked — the first working Pi4J example on a non-Raspberry Pi board. Benchmark results show the BPI-M4 Zero outperforms the Raspberry Pi Zero 2 by 35-47% and beats the pricier BeagleY-AI. The BPI-F3 RISC-V board performs comparably to the OrangePi RV2. Main downsides include poor documentation, outdated OS images, no dedicated imager tool, and significantly increased prices due to memory chip shortages.
