<https://forum.armbian.com/topic/3730-wiringop-on-opi-zero/#comment-33183>
<http://schema.org/text>
"Add a -lpthread to the gcc line and it'll work fine:\n \n\n\ngcc -o blink blink.c -lwiringPi -lpthread\n\n\n\tThe wiringPi library includes headers from the pthread library.\n \n\n\n\t \n \n\n\n\tAlso note that there are at least TWO versions of the wiringOP/wiringPi libraries for the Orange Pi's, one for the 26 pin OP-Zero ( https://github.com/xpertsavenue/WiringOP-Zero ) and one for the 40-pin OP's ( https://github.com/zhaolei/WiringOP ) and they ARE different. I made the mistake of installing the 40-pin version on an OP-Zero and then was wondering why it wasn't working (I'd accidentally connected a MAX6755 the wrong way and had wires almost melted before I pulled it back off. Then I'd also reformatted the SD card and reloaded things. So I figured at first I'd fried some of the GPIO pins when I couldn't get things to working again til I realized it was just due to the wrong library. I'd hooked up LED's to all the GPIO pins and was cycling them to see which had gotten fried and they all worked but NOT as expected. I.e. I'd set pin 3 high and maybe pin 10's LED came on. Once I swapped the libraries, it worked fine.\n \n"
<https://forum.armbian.com/topic/3730-wiringop-on-opi-zero/?tab=comments>