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Soldered Electrochemical H2S Gas Sensor Breakout (Qwiic)

This board measures hydrogen sulphide (H2S) from 0 to 300 ppm with an SGX-4H2S-300 electrochemical cell. An LMP91000 analog front end biases the cell and turns its current into a voltage, a 16-bit ADS1115 ADC converts that voltage, and an ATtiny404 talks to both chips for you, so your microcontroller sees a single I2C device at 0x30. Plug it in over Qwiic and read the gas concentration with the Arduino or MicroPython library.

Purple square gas sensor breakout seen at an angle, with the round black gas cell underneath, two Qwiic connectors and an ADDRESS DIP switch
The breakout with its H2S gas cell
Top of the breakout: ADDRESS switch top left, a Qwiic connector on each side, header pads along the top and bottom edges, jumpers JP1 to JP6 labelled
Top side
Underside of the breakout with the round gas cell in the middle, pin labels along both header rows and a list of gas names on each side
Bottom side with the gas cell

This documentation is for​

Purple square gas sensor breakout seen at an angle, with the round black gas cell underneath, two Qwiic connectors and an ADDRESS DIP switchProductSoldered Electrochemical H2S Gas Sensor Breakout (Qwiic)Hydrogen sulphide sensor board with an SGX-4H2S-300 electrochemical cell for 0 to 300 ppm, read over Qwiic.SKU 333331ShopBuy it on our shopPrice, stock and every variant of this product in the Soldered shop.https://soldered.com/products/soldered-electrochemical-h2s-gas-sensor-breakout-qwiicOpen the shop page

The board's silkscreen reads solde.red/333417. It is the same board, sold as SKU 333331, and these pages describe it.

At a glance​

InterfaceI2C over Qwiic, address 0x30 (0x30 to 0x37 by switch)
Main ICTexas Instruments LMP91000 analog front end
Gas and rangeH2S, 0 to 300 ppm (SGX-4H2S-300 cell)
Response timeT90 under 30 s
Voltage3.3 V only, no regulator
Connectors2x Qwiic, 2.54 mm headers
Dimensions38 x 38 mm
EnvironmentsArduino, MicroPython

What's in the box​

QtyItemNotes
1Soldered Electrochemical H2S Gas Sensor Breakout (Qwiic) (main product)SKU 333331
1Header pins (unsoldered)For the board's 2.54 mm header rows