SPIDER Gateway

README.md

SPIDER

BLE MIDI gateway — bridge Bluetooth LE MIDI controllers to USB MIDI and DIN MIDI, with up to three simultaneous BLE devices, fixed slot routing, and HOST / CLIENT roles for stage and DAWless setups.

Part of the Ash Sound Works custom tools for live and studio — by sound artist and producer Ash (Ahn Sunghoon) · GitHub / Manual

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Why SPIDER?

Running cables across a crowded pedalboard or needing remote control for other players is awkward. SPIDER was built around BLE MIDI on a dedicated nRF52840 radio (e.g. nice!nano class hardware): low power, battery-friendly, and focused on wireless MIDI rather than sharing the stack with a desktop OS BLE stack.

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Key features

• Up to 3 BLE MIDI controllers connected at once
• USB MIDI via TinyUSB — 3 independent virtual MIDI ports (one per slot)
• DIN MIDI — Slot 0 routes to DIN when appropriate (see routing below)
• 7.5 ms BLE connection interval class; low-latency slot timing (~5 ms average response in typical use)
• TX power auto-adjust 0 ~ +8 dBm from RSSI
• Battery monitoring for the unit and connected gear (where supported)
• OLED UI with power-save brightness (USB vs battery profiles)
• HOST and CLIENT modes

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Routing architecture

HOST mode

• USB data connected: BLE → USB MIDI (DIN blocked for that path per firmware logic)
• No USB data: Slot 0 → DIN MIDI output
• Slot management: RESCAN, CLEAR SLOT, auto-reconnect

CLIENT mode

• Uses one slot to join a host
• Remembers first trusted host MAC (save window ~30 s on first connect); optional block for unwanted devices

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OLED / status (summary)

• Top line: LOW BAT, WEAK SIG, M (DIN active), TX power hints
• Per slot: EMPTY / OFFLINE / CONNECTED
• MIDI traffic: ▽ in / △ out
• Battery: % or N/A if unknown

Antenna bars (signal guide)

• 6–4 bars — best; within ~10 m reliable
• 3 bars — stable for normal use
• ≤2 bars — TX power ramps up; maintain connection
• 0 bars — unreliable; move closer

Tip: Keep 3+ bars within ~10 m for dependable live use.

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Ableton Live (quick setup)

Preferences → Link / Tempo / MIDI

• Input: SPIDER MIDI Port 1, 2, 3 → Track ON, Remote ON as needed
• Output: enable if you send MIDI back to wireless gear

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Sync calibration

BLE adds variable delay; align with audio using Track Delay like any MIDI path. Many setups start around −10 ms ~ −20 ms (often −18 ms) and refine by recording MIDI out + external audio and matching to the grid.

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Firmware update

1. Connect SPIDER over USB.
2. Hold the encoder button for 5+ seconds to enter firmware update mode (USB mass storage / removable drive).
3. Copy the released firmware file to the mounted drive; device updates and reboots.

(Exact filename and format follow your published release notes.)

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Use cases

• Band live — multiple wireless controllers into one DAW reliably
• DAWless — Slot 0 → hardware synths via DIN
• Multi-computer — advanced MIDI routing between several hosts (see full manual)

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Repository contents

Depending on branch or release:

• Firmware (Zephyr / Arduino / etc. — match your repo)
• Schematics / PCB / case files
• Build and flash instructions

Full wiring, menus, and edge cases: spider-manual.html in the Ash Sound Works bundle.

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Hardware Specifications (BOM)

Documentation

• Full manual: spider-manual.html
• Other projects: github.com/nunosmash

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Disclaimer

• BLE performance depends on environment, antennas, and interference — always test before a show.
• Verify DIN polarity (Type A/B) when connecting legacy MIDI gear.
• DIY: observe battery and USB power safety.

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License

See the LICENSE file in the repository root.