A. Study G-Code from tutorial link :

 * basic tutorial for real  beginners like me.

  1. https://youtu.be/bpNNaTUi_7c?si=nDksQHwAnOiW5ruL

  2. https://youtu.be/YnysLfmyTn4?si=_a4UEnDMKm-qyelr

  3. https://youtu.be/8KNABE3IFgQ?si=IRc0lBuVj9u9i8Pq

B. Re-connect my mini CNC with R-Pi 4 to start testing.

C. Make my own program to communicate with R-Pi 4 to control CNC from my own program using G/M Codes