This isn't really a how-to. Currently it is mostly to show the different parameters available and their usage.
The MP Mini Delta has many options to choose from when it comes to Automatic Bed Leveling. The name automatic bed leveling may be a little misleading because the bed is not being leveled or adjusted in anyway. (This will be a simplified explanation for now at least). During the leveling process the printer probes the bed which activates the switches under the bed. The firmware the uses these measurements and depending on the options used it applies an algorithm that compensates for any unevenness and then makes adjustments as it is printing.
Note: The G28 (Home) command must be used prior to using any G29 command to ensure proper leveling
Gcode commands and parameters are to the left of the semicolon. Gcode comments are to the right of the semicolon and end at the end of the line.
G29       ; 3 point = 3 corners (center point using calculation) - DOUBLE TAP
G29 P1 ; 3 point = 3 corners (center point using calculation) - DOUBLE TAP
G29 P2 ; 4 point = 3 corners + center (real center) - DOUBLE TAP
G29 P3 ; 3×3 matrix - DOUBLE TAP
G29 P4 ; 4×4 matrix - DOUBLE TAP
G29 P5 ; 5×5 matrix - DOUBLE TAP
G29 P6 ; 6×6 matrix - DOUBLE TAP
G29 C[offset] ; offset option to fine tune center height. Does not apply to P3, P4, P5, or P6
G29 Z[offset] ; matrix/mesh offset
G29 P[mesh] Z[offset] ; Parameters may be combined
G29 Z[offset] P[mesh] = G29 P[mesh] Z[offset] ; Parameter order does not matter
G29 P2 Z0.39 C0.03 ; Parameters may be combined
G29 C-0.8 Z0.3 ; 3 point, with a 0.8mm center offset and a 0.3mm overall offset.
G29 P5 Z0.32 = G29 Z0.32 P5 ; Parameter order does not matter
G29 P2 Z0.4 C0.1 ; 4 point, with 0.4mm offset and an additional 0.1mm center offset.
G29 C0.1 ; 3 point with 0.10mm center offset.
G29 Z0.35 ; 3 point with 0.35mm offset
G29 P1 Z0.05 ; 3 point with 0.05mm offset
G29 P1 Z0.32 C0.05 ; 4 point with 0.32mm offset and an additional 0.05mm center offset
G29 P2 Z0.07 C0.02 ; 4 point with 0.07mm offset and an additional 0.02mm center offset
G29 Z0.18 P2 ; 4 point with 0.18mm offset
G29 P3 Z0.03 ; 3×3 matrix with 0.03mm offset
G29 P4 Z0.42 ; 4×4 matrix with 0.42mm offset
G29 Z0.33 P4 ; 4×4 matrix with 0.33mm offset
G29 P5 Z0.27 ; 5×5 matrix with 0.27mm offset
G29 P6 Z0.38 ; 6×6 matrix with 0.38mm offset
If you would like to see the X and Y coordinates along with the probing data at each point as it is probing use G29 P# V4. You can change P# to any of the other G29 P#.
G29 P1 V4 ; 3 point = 3 corners with detailed report
G29 P2 V4 ; 4 point = 3 corners + center with detailed report
G29 P3 Z0.37 V4 ; 3×3 matrix with detailed report
G29 P6 V4 ; 6×6 matrix with detailed report