Adafruit BME688 Temperature, Humidity, Pressure & Gas Sensor - I2C/SPI with Stemma QT

The Adafruit BME688 breakout board includes an onboard 3.3V regulator and level shifting, allowing it to be powered directly from a 3.3V to 5V DC supply. The logic levels for I2C/SPI communication are automatically handled, making it safe to use with both 3.3V and 5V microcontrollers like Arduino Uno, ESP32, and Raspberry Pi.

You can connect via the standard 0.1" pitch headers using Jumper wires for I2C or SPI, or use the solderless Stemma QT connector (Qwiic compatible) for a plug-and-play I2C connection. The default interface is I2C, but a solder Jumper on the board allows you to switch to SPI mode if required. Ensure you connect the VIN, GND, SDA/SCL (I2C), or the corresponding SPI pins.

The temperature, humidity, and pressure sensors are factory calibrated, providing accurate readings out-of-the-box. However, the metal oxide (MOX) gas sensor for VOC detection benefits from user calibration and baseline learning in the target environment for optimal performance, as its sensitivity can be influenced by ambient conditions and specific gas concentrations.

The integrated metal oxide (MOX) gas sensor is sensitive to a broad range of Volatile Organic Compounds (VOCs), including alcohols (like ethanol), carbon monoxide, and other reducing gases. It provides a general air quality index rather than identifying specific gas concentrations. The programmable heater allows tuning the sensor's sensitivity profile for different VOC groups.

The BME688 is the direct successor to the BME680, sharing the same hardware footprint and core environmental sensing capabilities. The key upgrade is the addition of a programmable gas-sensor heater in the BME688, offering more advanced control over the metal oxide sensor's temperature profile. This enables more sophisticated odor analysis and sensitivity tuning compared to the fixed heating profile of the BME680.