Description

This board contains two sensors. Both sensors communicate via I2C and the board can be driven between 1.8 V and 3.3 V.

SGP40

The SGP40 is a Metal Oxide (MOx) based multi-pixel gas sensor which is sensitive to almost all Volatile Organic Compunds (VOCs). It features on-chip processing for temperature and humidity compensation. The signal is proportional to the logarithm of the sensing material's resistivity.

Sensirion also provides an algorithm to convert the raw signal to a VOC index as a robust measure for indoor air quality (IAQ).

SHT40

The SHT40 is a high accuracy 16-bit relative humidity and temperature sensor. The values measured can be written to the SGP40 to get a compensated raw signal.

Features Overview

• High Accuracy Temperature and Relative Humidity Sensor
• Multi-Pixel Gas Sensor with on-chip T/RH compensation
• Longevity >10 years
• I2C Bus Interface
• 1.8 - 3.3 V
• Low Power Consumption ~2.6mA
• Overvoltage/ESD Protection
• 2x 2mm mounting holes

Drivers

Sensirion

Sensirion has put great efforts in an open source ecosystem around their products. You can find their embedded drivers written in C on their github: SGP40 SHT40

Adafruit

Adafruit has a SGP40 driver for their own ecosystem: SGP40

Micropython

I have written a pure MicroPython driver and implementation of Sensirion's VOC algorithm you can find here: SGP40/SHT40

Zephyr Project

I have also made an example application for the excellent Zephyr RTOS.

Links

Sensirion Product Pages

SGP40 SHT40