Design rules

BeeHive has deliberately few rules. Enough to keep every board interoperable and buildable anywhere — but not so many that they get in the way of new ideas. A handful are strict; the rest are strong recommendations.

Strict rules

These define what makes a board "BeeHive". Follow them and your board works with everything else.

1. Two types of board. Mainboards carry a microcontroller. Daughter boards each perform one function (e.g. control a solenoid valve).
2. One connector. Main-to-daughter connections use a 4-pin connector: two general-purpose I/O (data) lines, one power line (VCC), and one ground line (GND).

Recommended rules

Follow these so anyone, anywhere, can build and understand your board:

• 1–2 PCB layers. Keep routing to top and bottom layers so boards can be replicated locally with perfboard, chemical etching, or CNC — or ordered cheaply from JLCPCB, PCBway, OSH Park, or Aisler.
• Through-hole components so boards can be hand-soldered with minimal kit, by people with no prior experience.
• Populate one side of the board only.
• Label everything by the existing convention: connector pin identifiers, the daughter-board name, and a version number.
• Prefer a standard size:
  • Big — 71 × 45.5 mm
  • Small — 48.5 × 45.5 mm
• Size up if the board is getting cramped.
• Mounting holes: typically 4, for M3 screws, each centre 3.5 mm from the board edge.
• If in doubt — reach out!