Smart Hex wiring

These are logical interfaces. Pin assignment TBD. They are not PCB schematics or final wiring instructions.

Inter-hex connections

HEX A                      HEX B
5V        ──────────────── 5V
GND       ──────────────── GND
SDA       ──────────────── SDA
SCL       ──────────────── SCL
CHAIN_OUT ──────────────── CHAIN_IN

Power, ground, SDA, and SCL are shared. CHAIN is directed: each module has separate input and output GPIOs. Connector pin order, orientation, contact rating, and end-of-chain handling are TBD.

Main chain output → H0 input
H0 output         → H1 input
...
H5 output         → H6 input
H6 output         → end (termination behavior TBD)

Shared and local buses

Main SDA/SCL ───── CH32 main-bus interface
                        │
                 separate local GPIOs
                        │
                 local OLED SDA/SCL

Do not directly join the local OLED lines to the global bus. Separate buses avoid repeated OLED-address collisions. Shared-bus pull-ups around 4.7kΩ are an initial idea, not a verified selection. The pull-up rail must be compatible with every connected device; a 5V power rail does not imply 5V I²C logic.

Before defining wire lengths or bus speed, check aggregate pull-ups on modules, capacitance, signal levels, and behavior if a hex loses power. CHAIN also needs compatible levels and defined startup behavior so multiple unaddressed hexes cannot accidentally respond together.

Sensors and power

Each analog channel uses its own voltage divider. Robber sensing uses a proposed pulled-up input switched to ground. Local smoothing is approximately 10µF across the input rail. See power distribution.

The fixed chain order establishes location only when assembly follows that order. Physical orientation and sensor numbering must match the eventual ownership map.