Environmental Sensing Service

The Environmental Sensing Service (ESS) implements access to the BME680 environmental sensor of the card10.

It provides:

  • Temperature

  • Relative humidity

  • Pressure

If BSEC is enabled the following additional estimates are available:

  • Indoor air quality (IAQ estimate

  • Equivalent CO2 (eCO2) estimate

Please refer to bme680 for more information about BSEC.

If notifcations are enabled a measurement of all values is performed every 3 seconds. For each measurement a notification is sent for the characteristics which have notifications enabled.

A measurement can also be triggered by reading from a characteristic. A measurement takes roughly 200 ms. A notifciation will be sent to all characteristics which have notifications enabled except the one which was used to trigger the measurement.


If BSEC is enabled, reading a characteristic will not trigger a new measurement.


This service will be available in version v1.17.

BLE Service

  • Service

    UUID: 181A

  • Temperature characteristic:

    UUID: 2A6E read and notify

  • Humidity characteristic:

    UUID: 2A6F read and notify

  • Pressure characteristic:

    UUID: 2A6D read and notify

  • Indoor air quality (IAQ) characteristic:

    UUID: 422302f1-2342-2342-2342-234223422342 read and notify

Temperature characteristic

  • 16 bit little endian value representing the measured temperature.

  • Unit: 0.01 deg C

Humidity characteristic

  • 16 bit little endian value representing the measured relative humidity.

  • Unit: 0.01%

Pressure characteristic

  • 32 bit little endian value representing the measured pressure.

  • Unit: 0.1 Pa (0.001 hPa)

Indoor air quality (IAQ) characteristic

Data format:

Byte 0

Bytes 1-2

Bytes 3-4


IAQ (16-bit little endian)

eCO2 (16-bit little endian)


  • Accuracy and IAQ units: See BSEC API description

  • CO2 unit: [ppm]