Arduino Nano CNC Shield V4 with grbl PIN ERROR

The CNC Shield V4 came with some factory errors being a cloned version for china, the step puls and step direction pin numbers have been alternated, this article also show how to correct it. Just modify one file.

modify cpu_map.h file at line 39

#define X_STEP_BIT 5 // Uno Digital Pin 2
#define Y_STEP_BIT 6 // Uno Digital Pin 3
#define Z_STEP_BIT 7 // Uno Digital Pin 4

and line 47

#define X_DIRECTION_BIT 2 // Uno Digital Pin 5
#define Y_DIRECTION_BIT 3 // Uno Digital Pin 6
#define Z_DIRECTION_BIT 4 // Uno Digital Pin 7


save and exit

recompile and upload firmware

and done.