Gases - CO2 CDM7160

CO2 sensor

Plugin details

Type: Gases

Name: CO2 CDM7160

Status: COLLECTION D CLIMATE

GitHub: P127_CDM7160.ino

Maintainer: tonhuisman, V0JT4

Used libraries: .

Description

I2C CO2 sensor with altitude correction. Though the sensor also supports a serial connection and a PWM output, only I2C communication is supported by this plugin.

Usable measured values will be in the range 400..5000, outside that range the measurements are unreliable (and probably unrealistic).

NB: During power-on of the sensor, the reported values are completely out of range, > 15000, so these values are ignored. This will stabilize within a few minutes, and acceptable measurments will be reported.

If the measured values returned are > 10000, this is reported in the log (Info level), and most likely the sensor needs to be cleaned, when not in the initialization phase.

CDM7160 sensor

Image of a CDM7160 sensor (image sourced from Aliexpress)

Configuration

Device configuration

  • Name A unique name should be entered here.

  • Enabled The device can be disabled or enabled. When not enabled the device should not use any resources.

I2C Options

The available settings here depend on the build used. At least the Force Slow I2C speed option is available, but selections for the I2C Multiplexer can also be shown. For details see the Hardware page

  • I2C Address: The address the device is using. Depending on the state of the CAD0 pin, the address can be changed, open or high state selects the default address 0x69, when connected to GND, the configured address is 0x68. If more than 2 sensors have to be connected, an I2C multiplexer (in a custom ESPEasy build) can be used to use more than 2 sensors on a single ESPEasy unit.

Device Settings

  • Altitude: To compensate for local air pressure, the altitude relative to sea-level of the location where the sensor is installed can be entered. As usual for this type of setting, the altitude is registered in meter.

Data Acquisition

The Data Acquisition, Send to Controller and Interval settings are standard available configuration items. Send to Controller is only visible when one or more Controllers are configured.

  • Interval By default, Interval will be set to 60 sec. The minimum value allowed is 1 sec. but for measuring CO2 values, that don’t change very quickly, reasonable values could be between 10 and 300 sec.

Values

The measured value is available in CO2. A formula can be set to recalculate. The number of decimals is by default set to 0, as decimals are not available from the sensor.

Commands

Command Syntax

Extra information
cdmrst
Resets the sensor. (Documentation does not state what is actually reset, but it is assumed that the Altitude setting is reset to it’s default value 0.)

Change log

Changed in version 2.0: added 2021-12-31 Moved to main repository as Plugin 127 Gases - CO2 CDM7160 from the ESPEasyPluginPlayground (P176).