I'm working on a Duo project that needs SPI and this is how I configured and tested it without the mini shield.   Requirements: NanoPi Duo with test Armbian image 1 female to female jumper wire Enable SPI on boot: sudo nano /boot/armbianEnv.txt Add spi-spidev to overlays= Add line param_spidev_spi_bus=1 sudo reboot If everything worked you should have /dev/spidev1.0. Check with ls /dev/spi*. Now we can test with a C program: cd wget