This is a parametric first layer test print generator written in OpenSCAD. OpenSCAD source code is included. You can customize:

• The number of rows and columns to be printed.
• The size of shapes to be printed at each test point.
• Selection of circular or square shapes to be printed at each test point.
• The width of connecting lines to ease post-print removal.
• Enabling and optional center test point.

I've also included a variety of test prints generated for the Prusa i3 Mk3 (250x210mm), Prusa Mini (180x180) and Artillery Sidewinder X1 (300x300mm) print beds.