# Maker builds custom purple gas-discharge display with platinum sputtering and Arduino

> **Key takeaway:** A maker created a novel two-digit purple 5-segment display using platinum PVD sputtering, argon gas discharge, and a Nixie driver IC controlled by Arduino.

**Published:** 2026-10-24T12:39:26+00:00 
**Source:** Hackster.io News 
**Category:** open-hardware 
**Canonical URL:** https://fosswire.org/news/maker-builds-custom-purple-gas-discharge-display-with-platin.html 

## Summary
The maker known as Witchcraft and Alchemy has constructed a custom two-character display that produces a purple glow through low-pressure argon gas discharge rather than the familiar orange neon of Nixie tubes. The project employs physical vapor deposition (PVD) sputtering to coat an anode plate with titanium primer and platinum, with segments formed through masking. Due to a 10-output Nixie driver IC limitation, the builder chose a 5-segment format instead of conventional 7-segment displays. The final assembly resides in a milled aluminum vacuum chamber with a laminated glass window, with leads passing through sealant to external Arduino and driver circuitry. Some segments failed to operate correctly due to unspecified fabrication issues, but the proof-of-concept demonstrates a viable alternative display technology for hobbyist manufacture.

## How the purple display works
- **Gas discharge principle:** The display operates on the same physical principle as Nixie tubes—gas discharge around cathodes in a low-pressure environment—but uses argon instead of neon, producing a purple 2D-area glow rather than orange wire-shaped cathode illumination.
- **PVD sputtering construction:** The anode plate is coated via physical vapor deposition sputtering, first with titanium as a primer layer, then with platinum, creating conductive segments and traces through a masking process.
- **5-segment character encoding:** A standard Nixie driver IC provides only 10 outputs, insufficient for two independent 7-segment displays; the builder compromised on a 5-segment design that reduces readability but enables two characters with available hardware.
- **Vacuum chamber integration:** The final build seals the plate inside a milled aluminum enclosure with laminated glass viewport and vacuum port, with electrical leads penetrating through sealant to external driving electronics.
- **Control electronics:** An Arduino and dedicated Nixie driver chip sit outside the vacuum chamber, connected through pass-through wiring to address individual segments.

## Why it matters
This project matters for the open hardware community because it documents a reproducible path to custom vacuum-fluorescent-style displays without relying on dwindling Nixie tube supplies or proprietary manufacturing. The combination of accessible maker tools—Arduino, standard driver ICs, and benchtop PVD equipment—with documented gas discharge techniques gives hobbyists a template for building novel indicator and clock displays. For Linux and open source users, the Arduino-based control interface can be programmed with open toolchains, keeping the entire stack from hardware to firmware within the maker ecosystem.