vrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x7800
         0xff != 0x16
avrdude: verification error; content mismatch

// NOTE: Defaults are set for a traditional 3-axis CNC machine. Z-axis first to clear, followed by X & Y.
//#define HOMING_CYCLE_0 (1<<Z_AXIS)                // REQUIRED: First move Z to clear workspace.
//#define HOMING_CYCLE_1 ((1<<X_AXIS)|(1<<Y_AXIS))  // OPTIONAL: Then move X,Y at the same time.
// #define HOMING_CYCLE_2                         // OPTIONAL: Uncomment and add axes mask to enable

// NOTE: The following are two examples to setup homing for 2-axis machines.
// #define HOMING_CYCLE_0 ((1<<X_AXIS)|(1<<Y_AXIS))  // NOT COMPATIBLE WITH COREXY: Homes both X-Y in one cycle. 

#define HOMING_CYCLE_0 (1<<X_AXIS)  // COREXY COMPATIBLE: First home X
#define HOMING_CYCLE_1 (1<<Y_AXIS)  // COREXY COMPATIBLE: Then home Y

// Enable CoreXY kinematics. Use ONLY with CoreXY machines.
// IMPORTANT: If homing is enabled, you must reconfigure the homing cycle #defines above to
// #define HOMING_CYCLE_0 (1<<X_AXIS) and #define HOMING_CYCLE_1 (1<<Y_AXIS)
// NOTE: This configuration option alters the motion of the X and Y axes to principle of operation
// defined at (http://corexy.com/theory.html). Motors are assumed to positioned and wired exactly as
// described, if not, motions may move in strange directions. Grbl requires the CoreXY A and B motors
// have the same steps per mm internally.
#define COREXY // Default disabled. Uncomment to enable.