Trimix Analyser Connector

Divesoft data to Bluetooth labels

Build the ESP32-S3 Trimix Analyser Connector

Build a receive-only adapter for the documented Divesoft analyser port, then send checked oxygen and helium readings to a portable Niimbot printer.

Install firmware Download BOM (CSV) Open wiring diagram Download housing print files
Disconnect before USB flashing

Disconnect the adapter completely from the Divesoft analyser before every install or update. Connect only the ESP32-S3-Zero-compatible board by USB so USB power cannot backfeed or short the analyser connector.

Bill of materials

ESP32-S3-Zero-compatible adapter parts

In our testing, compatible non-Waveshare ESP32-S3-Zero boards have been more reliable than Waveshare boards, so we recommend a non-Waveshare version with the same pinout and dimensions. Buy it bare, without fitted headers or a housing.

Required parts

  • 1 × ESP32-S3-Zero-compatible board; non-Waveshare recommended
  • 1 × male DVI connector with solder pins or pads
  • Short insulated hookup wires or cable
  • 2 × M2.5 × 6 mm flat-head screws
  • 1 × printed housing set from MakerWorld
  • Optional: push button for manual printing
  • Older analysers only: DS3231 clock module

What to solder

Divesoft pin 4
ESP32 GPIO4
Divesoft pin 14 or 15
ESP32 GND
Divesoft pin 13
Optional switched 5 V to ESP32 5 V
Optional button
GPIO7 to momentary button to GND
Optional clock
Follow the labelled clock connections in the diagram
Divesoft analyser to ESP32-S3 adapter wiring diagram with data, ground, optional power, button, and clock
Solder only the labelled connections shown in the diagram.
  1. Prepare and dry-fit.Print the housing, fit the DVI connector and bare ESP32-S3-Zero-compatible board, and confirm the two M2.5 × 6 mm screws close the enclosure without touching the board.
    Divesoft analyser, ESP32 adapter, and Niimbot printer
    Check enclosure and connector fit
  2. Solder the data wire.Connect Divesoft rear connector pin 4 directly to ESP32 GPIO4, exactly as shown in the diagram.
    Top view of the DVI connector attached above the ESP32-S3 adapter board with its insulated wire routed beside the board
    Top-side board and wire routing
  3. Connect ground and optional power.Connect Divesoft pin 14 or 15 to ESP32 GND. If powering from the analyser, first measure and confirm switched 5 V on pin 13 before connecting it to ESP32 5 V.
    Bottom view of the DVI connector attached to the ESP32-S3 adapter board with short red and black soldered wires
    Bottom-side soldered connections
  4. Add only the needed options.The analyser pause normally triggers printing, so the separate button is optional. Add the clock module only for an older analyser without a usable date.
    Follow the diagram for optional parts
    Optional button and clock
  5. Flash with analyser wiring removed.Disconnect the adapter completely from the analyser. Connect only USB to the ESP32 board, open the installer in desktop Chrome or Edge, and use full install for a new board.
    USB only—no analyser connection
    Safe browser flashing
  6. Enable Divesoft data output.On the analyser select Menu → Preferences → Send Data to USB → On; some firmware calls it Data output. Without this setting, the adapter cannot receive live values.
    ESP32-S3 adapter connected to a Divesoft analyser displaying oxygen and helium
    Enable output before checking live data
  7. Configure the local Web UI.Join the setup Wi-Fi, add owner initials, pair the Niimbot printer, set the clock source and label options, and confirm basic or Pro licence status.
    Trimix Analyser Connector local Web UI
    Printer, Wi-Fi, owners, and labels
  8. Verify readings and a label.Compare live O2 and He values with the Divesoft display, trigger one label, and verify mix, MOD, END, date, and initials before field use.
    Niimbot printer with a Trimix analysis label
    Compare every label with the analyser