Distributed Show Control Concepts
NORTHSTARSHOW SYSTEMS
Distributed Show Control Concepts
Theory behind the Northstar architecture
| Document Number | Revision | Date | Platform Version |
|---|---|---|---|
| NSSS-DOC-0011 | A | 2026-05-20 | 1.0 |
Why Not a Single Show Computer
Traditional show racks centralise everything in one chassis: a show controller, audio playback unit, video player, lighting console, relay bank. The advantages are simplicity (one device) and determinism (no network).
The disadvantages compound at scale:
- Cable bulk — every effect cable runs back to the rack. A medium attraction with 50 effects easily has 2 km of dedicated signal cable.
- Failure modes — a single point of failure. A failed show computer cancels the night.
- Iteration cost — adding an effect means pulling new cables.
- Expansion limits — every show controller has a fixed channel count. Scaling means full hardware replacement.
The Distributed Alternative
Northstar replaces the central rack with a Wi-Fi mesh:
- One small computer (HelmOS NUC) runs show logic but has zero direct I/O.
- Tiny field nodes (Polaris UNO R4) carry the I/O — one per cluster of effects in a zone.
- Each node connects to the venue Wi-Fi and listens for UDP commands.
- The "cable" is power + Wi-Fi. Signal cables shrink to centimetres between a node and the effects it drives.
Trade-offs
| Concern | Centralised Rack | Northstar Distributed |
|---|---|---|
| Cable bulk | High | Minimal |
| Single point of failure | Yes — show computer | No — only the network spine |
| Adding an effect | Pull new cable | Add a node, edit a cue |
| Latency | <1 ms | 5–15 ms typical |
| Determinism | Hard real-time possible | Soft real-time, sufficient for show effects |
| Cost per channel | $50–200 | ~$5 (UNO R4 share) |
| Venue rewiring | Major project | Add/move a node |
What Northstar Sacrifices
The distributed design is unsuitable for applications requiring sub-millisecond determinism — for example, frame-locked video walls or laser shows synchronised to MIDI clock. For those, dedicated hardware remains the right answer.
Northstar excels at show effects with human-perceptible latency tolerance: relays, pneumatic valves, audio cue triggers, lighting changes, video file triggers, sensor-driven events.
The Air-Gap Principle
Show networks are kept off the public internet. The TrueNorth Wi-Fi has no uplink, no DNS, no NTP. The benefits:
- Reliability — an ISP outage cannot cancel the show
- Security — no exposure to public threats
- Determinism — no contention with guests' phones or venue Wi-Fi
- Privacy — no telemetry leaves the building
Related Documents
- NSSS-DOC-0010Architecture Overview
- NSSS-DOC-0006TrueNorth Network Design
Revision History
| Revision | Date | Description |
|---|---|---|
| A | 2026-05-20 | Initial publication |