I still can't make it work. Have cloned your files and replaced the bcm2835.c and bcm2835.h with the new ones as well as replaced the ArduiPi_OLED.cpp and the makefile in the original ArduiPi_OLED directory with your ones but still i get the /usr/bin/ld: cannot find -li2c error. Any ideas - what am I doing wrong please. (Raspberry Pi 3 with Stretch fresh install then followed hallard instructions, then replaced files you mention). Many thanks.