Hidden features
Height map scan using an external distance sensor.
1) In Surfcae scan window, set Max. probing depth to 0.000. Instead of probing command "G38.3Z123" an internal command will be set "($PROBE)" for later evaluation.
2) Setup the DIY control: it must send height information in this form "(PRB:Z0.123)", where 0.123 the measured distance is. The transmitted value will be stored in GRBL-Plotter and applied if a "($PROBE)" command appears during the streaming.
https://www.generationrobots.com/de/403292-tof-entfernungsmesser-vl6180.html
https://github.com/sparkfun/ToF_Range_Finder_Sensor-VL6180
https://learn.sparkfun.com/tutorials/vl6180-hookup-guide