OpenGarden

OpenGarden is a modular self-watering planter project built around OpenGrid-style mechanical mounting, 3D-printed parts, and a future ESP32-based watering controller.

The current work is focused on the mechanical CAD for a wall-mounted holder, drain/reservoir area, and removable pot insert. Electronics, firmware, backend, and UI folders are reserved for later phases.

Current Status

• OpenSCAD CAD modules for the holder, drain pan, back plate, and pot insert
• BOSL2 attachable anchors for assembling the pot insert into the holder
• Main OpenSCAD entry point with assembly and print/export layouts
• Research and design notes for self-watering strategies

Repository Layout

OpenGarden/
  cad/
    openscad/                 OpenSCAD CAD source files
  docs/
    mechanical/               Mechanical design notes
    self_watering_research/   Research notes and reference images
    self_watering_design.md   Current system design direction
  assets/                     Project assets
  backend/                    Reserved for backend services
  electronics/                Reserved for circuit/electronics files
  firmware/                   Reserved for ESP32 firmware
  scripts/                    Reserved for helper scripts
  ui/                         Reserved for user interface work

CAD Workflow

The main CAD entry point is:

cad/openscad/main.scad

Open it in OpenSCAD Nightly and use the Output_Mode customizer value:

Output_Mode = "Assembly"; // [Assembly, Freestanding Pot, Print Layout, Holder Only, Drain Only, Pot Insert Only]
OpenGrid_Support = true;
Render_Quality = "Preview"; // [Preview, Export]

Modes:

• Assembly: shows either the OpenGrid holder assembly or the freestanding drain/pot assembly, based on OpenGrid_Support
• Freestanding Pot: assembles the drain pan and pot insert without the OpenGrid back plate
• Print Layout: places the printable parts side by side; with OpenGrid_Support = true it shows the holder and pot insert, and with OpenGrid_Support = false it shows the drain pan and pot insert
• Holder Only: exports just the holder
• Drain Only: exports just the drain pan/reservoir section
• Pot Insert Only: exports just the removable insert

Set OpenGrid_Support = false when printing a freestanding pot that does not mount to OpenGrid.

Set Chamfer_Back_Side = true to apply the side chamfer to both sides of the freestanding drain pan and pot insert. OpenGrid holder mode keeps the holder-facing chamfer style.

For OpenGrid holders, Subtracted_Slots reduces the back-plate slot count and Slot_Placement controls whether the remaining slots stay centered, move to the left/right side of the plate, or spread across valid OpenGrid positions.

The insert drain hole pattern can be set with Hole_Pattern and adjusted with Hole_Rows, Hole_Columns, Hole_Diameter, and Hole_Area_Padding. The pattern is generated inside each pot insert grid cell. Rectangle uses rows and columns; Circle uses rows as a maximum ring count and columns as holes per ring. Circle mode may use fewer rings when a cell is too small to fit the requested rings cleanly.

The pot insert interior is always treated as a grid. Grid_Row_Sizes and Grid_Column_Sizes are comma-separated strings; each item creates one row or column, so 1* by itself creates one open compartment, while 1*,1* creates two equal tracks. Track values can use relative weights such as 1* or 2*, plain numeric weights such as 1, or percentages such as 25%. Grid_Cell_Spans can merge walls with 1-based row,column=rowspanxcolspan entries, such as 1,1=1x2;2,2=2x1. Spans merge the interior divider walls and make the spanned cell behave as one feature area. Grid_Wall_Thickness controls the divider wall thickness, and Fill_Tube_Clearance leaves a small margin around FillTube bottom cutouts.

Cell behavior is controlled by the cell-feature registry. Cell_Default_Feature is used by every cell that does not have an override. Pot is a drain-hole cell, Box is closed at the bottom, FillTube is an open-bottom tube cell, and WickPort is a single wick hole.

Cell_Feature_Overrides is a sparse per-cell list using 1-based row,col: feature,key=value,key=value entries separated by ;. This syntax avoids programming-style parentheses in the OpenSCAD Customizer. Short aliases are supported:

• dh or p — drain_holes / Pot
• b — box
• ft or f — fill_tube / FillTube
• wp — wick_port
• ll — lid_lip
• pattern=C and pattern=R — Circle and Rectangle

Built-in features:

• drain_holes (dh, p) — BOTTOM. Params: pattern, rows, cols, diameter, padding. Unspecified params fall back to the global drain-hole settings.
• box (b) — BOTTOM. Closed floor, no cutout.
• fill_tube (ft, f) — BOTTOM. Open-bottom tube cell. Param: clearance.
• wick_port (wp) — BOTTOM. Single centered wick hole. Param: diameter.
• lid_lip (ll) — TOP_LIP. Rectangular ring recess at the top of the cell wall. Params: depth, width.

Examples:

Cell_Default_Feature = "Pot";
Cell_Feature_Overrides = "1,1: dh,pattern=C,rows=3,cols=6";
Cell_Feature_Overrides = "1,1: wp,diameter=10; 2,2: ll,depth=2";

Bottom-plane overrides replace the default feature for that cell. Top-lip overrides are additive, so the cell still uses Cell_Default_Feature for its floor. You can apply both planes to one cell by adding two entries for the same cell.

Each cell also exposes named BOSL2 anchors that external accessory .scad files can attach() to: cell_<row>_<col>_top, cell_<row>_<col>_bottom, cell_<row>_<col>_center, and cell_<row>_<col>_wall_n/s/e/w for cells on the corresponding boundary. Row and column are 1-based. Wall anchors only exist on grid-boundary cells.

Malformed or unknown Cell_Feature_Overrides entries are silently skipped.

The print layout spacing can be adjusted with:

Print_Spacing = 20;

Use Render_Quality = "Preview" while tuning the grid, roles, and hole layout. It lowers the global OpenSCAD facet count for smoother interaction. Switch to Render_Quality = "Export" for final STL output.

CAD Dependencies

The OpenSCAD files use BOSL2. The project has been tested with OpenSCAD Nightly.

Expected local OpenSCAD path on the current development machine:

C:\Program Files\OpenSCAD (Nightly)

To export from the command line:

& 'C:\Program Files\OpenSCAD (Nightly)\openscad.com' -o output.stl cad\openscad\main.scad

To export a specific mode:

& 'C:\Program Files\OpenSCAD (Nightly)\openscad.com' -D 'Output_Mode="Print Layout"' -o print-layout.stl cad\openscad\main.scad

Design Direction

The project is moving toward an active pump-based self-watering system:

• removable pot insert
• drain/reservoir section
• OpenGrid-compatible mounting
• future ESP32 pump control
• later support for moisture or water-level sensors

See docs/self_watering_design.md for the current design notes.

Development Notes

• Keep CAD modules reusable and avoid rendering sample objects from library files.
• Define shared BOSL2 anchor names in cad/openscad/anchor_names.scad.
• Use main.scad as the output/export entry point.
• Validate OpenSCAD changes by exporting the relevant Output_Mode values.
• Pull requests that change OpenSCAD files generate STL preview artifacts through GitHub Actions.
• Do not push feature work directly to master; create a branch and open a pull request first.

Contributing

Use short-lived branches for changes:

git checkout -b feat/your-change-name

Before opening a pull request, verify any CAD changes with OpenSCAD Nightly and include the tested Output_Mode values in the PR description. See CONTRIBUTING.md for the repository workflow.