Hi Rick
I am using BigtreeTech Skr mini E3 V2 board in the Ender 3, very quiet, + the TFT35 V3 display. I have the E3 turbo board but had several issues with it and octoprint. I to use Cura V4.8.
The car has several modes -
1. free roam
2. bluetooth remote control.
3. light follower.
4. light avoidence
5. Line follower - fast of slow mode.
6. Follow Me Mode
7. Wall follower.
8. Teach and playback.
Also has video camera with pan and tilt with 5.8 MHz tx.
MP3 voice.
40X2 is the main controller with 3 14M2s, 1 18M2 and one 08M2. digital compass and OLED display
Bill