I am using an APMv1 with a mega2560 and an Oilpan.  When I load the APMRover2 firmware through the mission planner software, the board works fine.  I downloaded the APMRover2 code from the git repo and I only modified the APM_Config.h file such that "#define CONFIG_APM_HARDWARE APM_HARDWARE_APM1" and "#define LITE  DISABLED".  I am able to make and upload the HEX file to the APMv1 board, but the accelerometer won't initialize?  Are there other config settings that I need to alter?  Any help is much appreciated...