The 26-pin expansion port of the Orange Pi Zero is placed on the opposite side of the board compared to Raspberry Pi while the pinout is exactly the same:
OSH Lab created a nice illustration of the Orange Pi Zero expansion port.
Orange Pi Zero GPIO Pins
It took me a while to discover that the General Purpose Input/Output (GPIO) numbering on the Orange Pi Zero with Armbian Legacy 3.4.113 is different from the Raspberry Pi and Raspbian. Here is how Allwinner SoC port names (such as PB12) are mapped to their GPIO pin numbers in the Linux kernel:
(Position of letter in alphabet - 1) * 32 + Pin number
For example, port
PB12 would map to
(2 - 1) * 32 + 12 = 44
Here is an online tool that does the GPIO mapping which I used when creating this illustration of the Orange Pi Zero GPIO pins:
Using the GPIOs
Knowing the GPIO pin numbers is important for building all the Raspberry Pi based projects since their GPIOs are numbered differently (not sure how they do it, probably map to the datasheet?). In the follow-up post I show how to add an LCD monitor to the Orange Pi Zero via the SPI bus.