The grbl firmware uses up a lot of the Arduino storage space but is designed to work very reliably regardless. The LongMill version is, if anything, a little bit smaller than the default grbl firmware ...

The proprietary control of CNC machines results in the inability to control and enhance inputs because the program codes cannot be modified owing to their distribution by vendors in the compiled form.

This procedure sends the cgode to the grbl shield, line for line, waiting for the ok signal after each line It also queries the machine status every 500 milliseconds and writes some status information ...