# Port Layout

## Overview

10 accessible ports + SD reader + Kensington lock, split across four case surfaces. Built-in WiFi+BT eliminates need for USB dongles.

## Port Side (Left, Facing Bow)

Data connections. "Plug and unplug frequently" zone.

| Port | Count | Source | Notes |
|------|-------|--------|-------|
| USB-A 3.0 | 4 | Powered hub | Flash drives, peripherals, hardware |
| USB-C (data) | 1 | Powered hub | Modern peripherals, data transfer |
| USB-C PD out | 1 | IP5389 board | Phone charging, 5V/??W |

## Starboard Side (Right, Facing Bow)

Networking + AV. "Plug in and leave" zone.

| Port | Count | Source | Notes |
|------|-------|--------|-------|
| Ethernet RJ45 | 1 | OPi3B native | Gigabit, panel-mount extension |
| HDMI out | 1 | HDMI A/B switch | External display, switched from internal |
| 3.5mm audio out | 1 | OPi3B native | Headphones, speakers, line-out |

## Bow Wall (Back Edge, Spine Side)

Power and cooling. No data ports.

| Feature | Notes |
|---------|-------|
| USB-C power input | For IP5389 board charging (5V/3A) |
| Fan exhaust grilles | Blowing away from user |

## Stern Edge (Front Edge, Lip)

User-facing. Clean for typing.

| Feature | Notes |
|---------|-------|
| Carry handle | Stern-mounted per design decision |
| SD card reader | Panel-mount, for camera cards / quick imaging |
| Kensington lock slot | Physical security |

## Internal Components

| Component | Connection |
|-----------|------------|
| Powered USB hub (10-port) | Decased, wired internally. Feeds all USB-A and USB-C data ports. |
| HDMI A/B switch (mechanical) | Passive toggle. OPi3B HDMI in, two outputs (internal display + starboard panel jack). |
|| eDP-to-HDMI controller | Connected to A/B switch output A. Drives internal display. |

## Constraints

- OPi3B has **one HDMI output**. The A/B switch selects internal or external — not both simultaneously.
- The internal display uses an eDP-to-HDMI controller board (matched to the salvaged panel). The native eDP port on the OPi3B is unused — direct connection was investigated but ruled out due to undocumented pinouts and voltage mismatch risk.
- DisplayLink USB graphics adapters **do not work on ARM Linux** (no drivers). Not a viable path for dual display.
- Dual simultaneous display would require a dual-HDMI SBC.
- Built-in WiFi 5 + BT 5.0 on the OPi3B — no USB dongles needed for wireless connectivity.
- Two native USB 3.0 ports available for direct connections (keyboard, mouse) without hub contention.