BarnacleBoy
3c11190822
- docs/sbc-selection.md: full rewrite for OPi 3B specs (RK3566, 8GB, 256GB eMMC, built-in WiFi) - README.md: SBC description, checklist, components table, quick ref, cost estimate - docs/parts-list.md: SBC marked purchased, eMMC/controller/WiFi changes - docs/design-decisions.md: WiFi exclusion reason, native eDP, power input - docs/salvage-analysis.md: WiFi card not needed, cooling fan, summary tables - docs/storage-architecture.md: rewritten for 256GB eMMC primary boot - docs/usb-expansion.md: 2x USB3 native, port allocation, power budget - docs/port-layout.md: OPi3B port differences (eDP, power-only USB-C, built-in WiFi) - docs/power-system.md: lower power draw context
252 lines
No EOL
7.4 KiB
Markdown
252 lines
No EOL
7.4 KiB
Markdown
# USB Port Expansion
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**Goal:** Multiple USB ports for cyberdeck peripherals
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---
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## Native Ports (Orange Pi 3B)
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| Port | Type | Speed | Location |
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|------|------|-------|----------|
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| USB 3.0 ×2 | Type-A | 5 Gbps | Board edge |
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| USB 2.0 ×2 | Type-A | 480 Mbps | Board edge |
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| USB-C | Power only (5V input) | — | Power input |
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**Total native USB:** 4 ports (2× USB 3.0, 2× USB 2.0)
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Still may benefit from a hub depending on peripheral count, but the OPi3B's 2× USB 3.0 natively doubles the bandwidth available vs the OPi5.
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---
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## USB Hub Solution
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### Why Powered Hub
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| Hub Type | Power Source | Issues |
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|----------|--------------|--------|
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| Bus-powered | Draws from OPi5 | Voltage drops, instability |
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| **Self-powered** | External 5V supply | **Stable, reliable** |
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**Orange Pi 5 USB power budget:** ~900mA total across all ports.
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**Device power draw:**
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| Device | Draw |
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|--------|------|
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| USB SSD | 500-1000mA |
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| WiFi dongle | 200-500mA |
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| Keyboard | 50-100mA |
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| Mouse | 50-100mA |
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| Webcam | 250-500mA |
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**Conclusion:** Bus-powered hub will cause brownouts. Use powered hub.
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---
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## Hub Options
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### Consumer-Grade
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| Model | Ports | Power | Cost |
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|-------|-------|-------|------|
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| Sabrent 7-Port USB 3.0 | 4× 3.0 + 3× 2.0 | Barrel jack | $20-25 |
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| Anker 7-Port USB 3.0 | 7× 3.0 | Barrel jack | $25-30 |
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| Anker 4-Port USB 3.0 | 4× 3.0 | Barrel jack | $15-20 |
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### Industrial
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| Model | Ports | Power | Cost |
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|-------|-------|-------|------|
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| USB Hub PCB (GL850G) | 4× 2.0 | External 5V | $8-12 |
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| Industrial USB 3.0 Hub | 4-7× 3.0 | External 5V | $15-30 |
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### Recommendation
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**Sabrent 7-Port USB 3.0 Powered Hub**
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- 4× USB 3.0 + 3× USB 2.0
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- External 5V barrel jack
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- Vertical orientation (compact)
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- ~$20-25
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---
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## Connection Diagram
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```
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┌─────────────────┐
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│ Orange Pi 3B │
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│ │
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│ USB 3.0 ───────┼─────┐
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│ USB 3.0 ───────┼──┐ │
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│ USB 2.0 ───────┼──┼──┤
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│ USB 2.0 ───────┼──┼──┤
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│ │ │ │
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└─────────────────┘ │ │
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│ │
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┌────────────────────┘ │
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│ │
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▼ │
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┌─────────────────────┐ │
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│ Powered USB Hub │ │
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│ (7-port) │ │
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│ │ │
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│ [Uplink] ◀────────┘ │
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│ │ │
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│ [1] [2] [3] [4] │ │
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│ [5] [6] [7] │ │
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│ │ │
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│ ┌─────────┐ │ │
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│ │ 5V DC │◄───────┼───────────┼── external power
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│ └─────────┘ │ │
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└─────────────────────┘ │
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│ │
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▼ │
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┌─────────────────────┐ │
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│ Peripherals │ │
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│ • SSD enclosure │ │
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│ • Keyboard │ │
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│ • Mouse │ │
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│ • Misc USB │ │
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└─────────────────────┘ │
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│
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Native ports still available: │
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• 2× USB 3.0 (if not used for uplink) ◄┘
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• 2× USB 2.0 (keyboard, mouse) ◄─┘
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```
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---
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## Port Allocation
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### After Hub
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| Port |Location | Purpose | Speed |
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|------|----------|---------|-------|
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| Hub Port 1 | Hub | USB SSD | 5 Gbps |
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| Hub Port 2 | Hub | Data transfer | 5 Gbps |
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| Hub Port 3 | Hub | Data transfer | 5 Gbps |
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| Hub Port 4 | Hub | Data transfer | 5 Gbps |
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| Hub Port 5 | Hub | Misc peripheral | 480 Mbps |
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| Hub Port 6 | Hub | Misc peripheral | 480 Mbps |
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| Hub Port 7 | Hub | Misc peripheral | 480 Mbps |
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| Native USB 3.0 | OPi3B | Keyboard | 5 Gbps |
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| Native USB 3.0 | OPi3B | Mouse | 5 Gbps |
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| Native USB 2.0 | OPi3B | BT dongle or spare | 480 Mbps |
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| Native USB 2.0 | OPi3B | Spare | 480 Mbps |
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**Total available:** 11 ports (7 from hub + 4 native)
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### Estimated Usage for Cyberdeck
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- 1× USB SSD (data storage)
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- 1× Keyboard (native USB 3.0 or 2.0)
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- 1× Mouse (native USB 3.0 or 2.0)
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- 4× Expansion ports (hub)
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---
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## Panel-Mount Options
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For a permanent cyberdeck build, mount USB ports on the case face.
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### Method 1: Panel-Mount Cables
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Pre-made cables with panel-mount USB-A connectors:
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- [Panel mount USB-A extension](https://www.amazon.com/s?k=panel+mount+usb+extension) (~$10-15 for 4-pack)
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- [Panel mount USB-C](https://www.amazon.com/s?k=panel+mount+usb+c) (~$10-15 for 2-pack)
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**Setup:**
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1. Mount connectors in case face
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2. Run cables inside to hub
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3. Secure hub internally
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### Method 2: Industrial Hub PCB
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Bare hub PCB designed for integration:
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- Mount PCB inside case
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- Wire panel connectors directly to PCB
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- Cleaner internal layout
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**Parts:**
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- USB hub PCB (GL850G or similar): $8-15
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- Panel-mount USB connectors: $10-15
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- Meanwell 5V 3A PSU: $8
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**Total:** ~$25-35
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---
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## Power Considerations
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### Hub Power Requirements
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| Specification | Value |
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|---------------|-------|
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| Input voltage | 5V DC |
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| Current | 2-4A (depending on devices) |
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| Connector | Barrel jack (usually) |
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### Powering the Hub
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| Method | Notes |
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|--------|-------|
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| Wall adapter (included) | Simple, separate power brick |
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| 5V from cyberdeck PSU | Integrated, requires 5V rail |
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| USB-C PD | Requires USB-C hub with PD pass-through |
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### Power Budget
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| Component | Draw |
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|-----------|------|
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| Orange Pi 3B (8GB) | 3-5W |
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| USB hub (self-powered) | 1-2W |
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| USB SSD | 2-4W |
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| Peripherals | 1-2W |
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| **Total** | **7-13W** |
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For portable build: 10,000-20,000 mAh battery pack with PD output.
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---
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## GPIO Alternative
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**USB hubs do not require GPIO.**
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GPIO (26-pin header) is for:
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- Serial console (TX/RX)
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- I2C devices (sensors, displays)
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- SPI devices (LCD, flash)
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- PWM (fan speed, servos)
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- Digital I/O (buttons, LEDs)
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If you want internal hub without USB cable:
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- Use GPIO for power only (5V/GND)
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- Still need USB data connection
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---
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## Cost Summary
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| Item | Cost |
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| Powered USB 3.0 hub (7-port) | $15-25 |
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| Panel-mount cables (optional) | $10-20 |
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| **Total** | **$15-45** |
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---
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## Recommended First Iteration
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1. Buy Sabrent 7-port powered hub ($20)
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2. Plug into Orange Pi 3B USB 3.0 port
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3. Use external power adapter
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4. Done — no custom wiring needed, and with 2x native USB 3.0, you have options for direct connections
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**When you're ready for permanent build:**
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- Removehub from plastic case
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- Mount PCB inside cyberdeck
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- Wire panel-mount connectors
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- Power from internal 5V rail |