Ventrix Vault-Core
The MCU + sensor board is placed and 96% auto-routed with zero DRC errors. One part — the humidity sensor — needs four wires drawn by hand. About five minutes in KiCad.
Vault-Core
- RAK11720 MCU (LoRa + BLE)
- Power: LiSOCl₂ cell → TPS7A02 3.0V
- W25Q256 flash · ATECC608B secure element
- SHT45 humidity/temp sensor
- Pt1000 probe block (fit-optional)
- Display header (JD)
Vault-Display
- 1.54″ e-paper panel (24-pin FPC)
- SSD1680 boost circuit
- Plugs onto Vault-Core via JD
- Sits next to the panel in the enclosure
Yes — the display and the MCU/sensor board are separate PCBs. Only Vault-Core exists as a layout so far; Vault-Display is the next board to design.
| Net | From | To | What it is | |
|---|---|---|---|---|
| SDA | U4 · pin 1 | → | U1 · pin 10 | I²C data |
| SCL | U4 · pin 2 | → | U1 · pin 9 | I²C clock |
| VDD | U4 · pin 3 | → | C9 (right beside U4) | 3.0 V power |
| GND | U4 · pin 4 | → | via ↓ ground plane | ground (bottom layer) |
- Open vault_core.kicad_pcb in KiCad PCB editor (path below).
- Press X for the interactive router. Click U4 pin 1, route to U1 pin 10 — KiCad's push-and-shove nudges other traces aside as you go.
- Same for pin 2 → U1 pin 9 and pin 3 → C9 (C9 is 2.5 mm away).
- For pin 4 (GND): place a via next to the pad with V — it drops to the bottom ground plane and ties in automatically.
- Refill copper zones with B, then run Inspect → Design Rules Checker. Expect 0 errors, 0 unconnected.
KiCad has no built-in autorouter — it uses Freerouting (the open-source one), which routed 96% of this board. Long wires running clear across the board to a corner-mounted sensor are exactly the kind an autorouter leaves behind, because the bottom layer is a solid ground plane and the top layer is crowded. Hand-finishing the last few nets with the interactive router is the normal, expected workflow — not a defect. The sensor sits at the enclosure vent on purpose (accurate humidity, away from chip heat), so it stays put.