CCS811 Carbon Dioxide and TVOC Air Quality Sensor

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Overview

A gas sensor capable of detecting a wide range of volatile organic compounds (VOCs), measuring eCO2 (equivalent calculated carbon-dioxide) concentrations in the range of 400 to 8192ppm and TVOC (Total Volatile Organic Compound) concentrations in the range of 0 to 1187ppb. It can be used to detect alcohols, aldehydes, ketones, organic acids, amines, aliphatic and aromatic hydrocarbons. It uses an I2C interface.

When first purchasing the module, it should be powered on for the initial 48 hours to perform burn-in. Additionally, measurements should be taken approximately 20 minutes after power-up to obtain accurate readings, as the sensor’s sensitivity changes slightly during the initial period.

Specifications

Voltage: 1.8 – 3.3V DC (3.3V recommended)
Current (continuous in mode 1): 30mA
Power (sleep mode): 19mA (at 1.8V)
Current (peak): 54mA
Temperature range (operation): -40°C to +85°C
Humidity range (operation): 10 – 95%

Supported GPIO

Raspberry Pi 0~4 (software interface only)
Raspberry Pi 5
BeagleBone Black/Green
Jetson Nano
FT232H, FT2232H, FT4232H
MCP2221

Commands

[INIT]

Enters initial configuration settings.

Item	Type	Description
Measurement Mode *	WRITE	Selects the measurement mode. (idle, 1s, 10s, 60s, 250ms)

* Idle mode is standby mode, while other modes take measurements at the specified time intervals.

[SET_DRIVE_MODE]

Sets or changes the measurement mode.

Item	Type	Description
Measurement Mode	WRITE	Selects the measurement mode. (idle, 1s, 10s, 60s, 250ms)

[READ_DATA]

Reads CO2 and TVOC concentrations.

Item	Type	Description
CO2 (ppm)	READ	eCO2 (equivalent calculated carbon-dioxide) concentration
TVOC (ppb)	READ	TVOC (Total Volatile Organic Compound) concentration

[SET_ENV_DATA]

Inputs environmental information (temperature, humidity). Used for more accurate CO2 and TVOC measurements.

Item	Type	Description
Humidity (%)	WRITE	Humidity of the measurement environment
Temperature (℃)	WRITE	Temperature of the measurement environment

[SET_BASELINE]

Sets the baseline.

Item	Type	Description
Baseline	WRITE	Enters the baseline value.

[GET_BASELINE]

Reads the configured baseline.

Item	Type	Description
Baseline *	READ	Reads the baseline. Should be read at least 20 minutes after the module is powered on.

* The CCS811 performs self-calibration each time it is powered on. Therefore, no separate calibration is needed when the environment remains the same. However, when the measurement environment changes (e.g., to an environment with higher CO2 and TVOC concentrations than before), calibration will introduce a constant offset, making direct comparison with the previous environment impossible. Therefore, to compare CO2 and TVOC concentrations across different environments using the same reference, a baseline must be set. Please refer to the baseline setting method below.

Example

Objective

Read CO2 and TVOC concentrations from the sensor and display them on dashboard widgets.

Parts

Part	Quantity
Raspberry Pi 4 *	1
CCS811	1

* Other hardware can also be used. Refer to Supported GPIO.

Wiring

CCS811	GPIO
VIN	3.3V
GND	GND
SCL	23 *
SDA	24 *
WAK	GND
ADD	Not Connected **

* Raspberry Pi 0~4 can only use software I2C interface due to hardware limitations, and any GPIO pins can be used.
** If not connected, I2C address is 0x5A; if connected to 3.3V, it is 0x5B. (May vary depending on module manufacturer.)

Project Link

Baseline Setting Method

Execute the GET_BASELINE command 20 minutes after the module is powered on to read the baseline.
Execute the SET_BASELINE command with the obtained baseline to store it in the module.
From now on, the stored baseline will be applied every time the module starts.
However, since measurement errors accumulate over time, the baseline should be reset after a certain period (several months).

References

Datasheet

Library