#define FXOS8700CQ_I2C_ADDR(SA) ((SA) == 0 ? 0x3C : \ (SA) == 1 ? 0x3A : \ (SA) == 2 ? 0x38 : \ 0x3E)
FXOS8700CQ_I2C_ADDR defines the FXOS8700CQ 8-bit I2C address selected by the SA1:SA0 signals. From the datasheet, the SA1:SA0 encoding is unexpected...