5 Mar 2019 — The Raspberry Pi Zero W board contains a single 40-pin expansion header labeled as 'J8' providing access to 28 GPIO pins.Numbering SchemeExpansion HeaderJ8 Pinout (40-pin Header)1 of 3Pi4J uses an abstract pin numbering scheme to help insulate software from hardware changes. Pi4J implements the same pin number scheme as the Wiring Pi project. More information about the WiringPi pinContinue on pi4j.com »2 of 3The Raspberry Pi Zero W board contains a single 40-pin expansion header labeled as 'J8' providing access to 28 GPIO pins. (Pins 1, 2, 39 & 40 are also labeled below.) (click here for hi-resolution imaContinue on pi4j.com »3 of 3The diagram below illustrates the GPIO pinout using the Pi4J/WiringPi GPIO numbering scheme. (click here for hi-resolution image)Continue on pi4j.com »