This low level driver is a test stub that doesn't talk to any real hardware. It is included to allow testing of the compilation process. Do not use this driver as a template for new drivers. Use the templates/gdispXXXXX directory for that. To use this driver: 1. Add in your halconf.h: a) #define HAL_USE_GDISP TRUE b) Any optional high level driver defines (see gdisp.h) you want to compile test eg: GDISP_NEED_MULTITHREAD 2. To your makefile add the following lines: include $(CHIBIOS)/os/halext/halext.mk include $(CHIBIOS)/os/halext/drivers/gdispTestStub/gdisp_lld.mk