general repository for programs.
gcc -O3 -Wall -I/usr/local/include -Winline -pipe -o bin/ultra -L/usr/local/lib -lwiringPi -lwiringPiDev -lpthread -lm -lcrypt -lrt src/ultra.c
gcc -lpigpio -lpthread -o bin/blink src/blink_leds.c gcc -lpigpio -lpthread -o bin/blink_all src/blink_all.c