Wireless gas readings on your iPhone

Read your DiveSoft Analyzer wirelessly and print professional tank labels in seconds. One of the biggest issues technical divers face is breathing the wrong gas at depth. Tanks should always be analyzed and labeled. While tape and a magic marker have worked there are better ways. GasTag + Label Printer is that way!

Great minds think alike! Divesoft has introduced native support for printing labels! They used a different printer and only need a special cable. Read about it in their blog. Maybe with the new firmware I can offer more options as well, stay tuned! With GasTag you can do all the printing from your phone and not the analyzer, and I use a Brother printer which you may already own.

⚠️ Requires DiveSoft Analyzer H2/O2 ⚠️ Requires GasTag Bluetooth Bridge (DIY or Pre-Built)

Build Your Own Get Pre-Built Download App
GasTag app showing gas readings and label preview

How It Works

From analyzer to printed label in four simple steps

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Step 1

Connect

ESP32 bridge plugs into your DiveSoft Analyzer's USB port

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Step 2

Pair

iPhone connects to the bridge via Bluetooth

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Step 3

Read

Live He, O₂, temperature, and pressure readings on your phone

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Step 4

Print

Print a tank label directly to your Brother QL-820NWB via Bluetooth

GasTag system layout showing Analyzer, Bridge, Phone and Printer connections

Analyzer, GasTag Bridge, Phone and Printer connections

Features

Everything you need for efficient gas analysis workflow

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Print or share labels

Print gas mix labels or share them as images — no printer required.

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Real-time readings

See gas mix data instantly on your iPhone as you analyze.

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Fully wireless

Bluetooth from analyzer to phone to printer. No cables to your phone.

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iPhone powered

Bridge runs off your iPhone's USB-C port. No extra batteries needed.

⚡

Background mode

App stays connected while you use other apps on your phone.

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Auto-reconnect

Automatically reconnects if the Bluetooth connection drops.

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Local history

All your gas readings are stored locally on your device for easy reference.

GasTag printed tank labels

Print or share labels

GasTag label applied to scuba tank

Label on tank

GasTag label applied to tank valve

Label on valve (optional)

GasTag gas log history screen

Local history

What You Need

Everything required to get started with GasTag

  • ⚠️
    DiveSoft Analyzer H2/O2 — Gas Analyzer, this is where GasTag gets the readings from
  • ✓
    Brother QL-820NWB label printer — For printing tank labels
  • ✓
    DK-2251 (red/black on white) or DK-2212 black/white only — Labels for printer
  • ✓
    PABU001 Brother Battery — For a truly portable solution
  • ⚠️
    iPhone 15 or later — Or any recent iPhone and a USB power bank
  • ⚠️
    GasTag Bridge — Build it yourself (~$25) or get pre-built
  • ⚠️
    GasTag iOS App — Available on the App Store

Choose Your Path

Build it yourself or get a ready-to-use unit

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DIY Builder

Build your own GasTag bridge for about $25 in parts.

View DIY Guide
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Pre-Built

Join the waitlist for a ready-to-use GasTag bridge.

Join Waitlist