PreGrbl intends to offload higher level tasks and computationally expensive routines from the on-board firmware of Grbl, primarily to keep Grbl simple and efficient. These tasks include more robust and complete NIST g-code error checking, implementing canned cycles by translating the tool paths, and converting the g-code into a Grbl-friendly format.

In the near future, PreGrbl may be used as a starting point for a full-featured CNC user interface for Grbl, much like EMC2 or Mach3. For example, a GUI interface would translate a g-code program with canned cycles into a Grbl-friendly format and stream it in the background directly to Grbl.

Current Features:
– Notifies unsupported g-code commands for grbl
– Converts G02/03 arcs to G01 linear interpolations
– Removes comments, block delete characters, and line numbers
– Removes spaces and capitalizes commands
– Minor input error checking
– OPTIONAL: Remove unsupported grbl G and M commands

To Do:
– Add canned cycle translation
– Number precision identification and truncation
– Arc conversion option
– More robust and complete error checking
– Command line interface options
– Improve g-code parsing to NIST standards
– Support inverse feed rates