Getting to know CCS811

Cambridge CMOSSensors (CCS) is a semiconductor company with local environmental monitoring gas sensor solutions in the industry. It has launched its ultra-low power consumption miniature gas sensor product, the CCS811.

CCS811 is a gas sensor that uses IIC for communication and has extremely low power consumption. But compared with some of the most common IIC sensors, it has more functions. Such as interrupt, enable, reset and corresponding pins, and program control involves mode and state switching.

CCS811, which integrates metal oxide gas sensors and microcontroller subsystems, enables smartphones, wearable devices and connected home devices to achieve Indoor Air Quality (IAQ) monitoring. It also simplifies the design, and extends battery life Time, in turn reducing system cost.

The sensor is based on CCS’s unique micro-heating plate technology. Compared with traditional metal oxide gas sensors, CCS811 provides a highly reliable gas sensor solution, and a fast test cycle, which significantly reduces average power consumption.

Features of CCS811

• Built-in microcontroller—manages sensor drive modes and measures Volatile Organic Compounds (VOC).
• Onboard processing capabilities—
  • Provides digital interfaces for equivalent carbon dioxide (eCO2) levels or total volatile organic compounds (TVOC) index standards without host intervention
  • Simplifies the integration of hardware and software to achieve faster time-to-market optimized low-power mode
  • Extends the battery life in portable applications. 2.7mmx4.0mm LGA package
• Small size design and a low number of peripheral components
  • Saves up to 60 % Of PCB occupies a board area.
  • A proven technology platform-designed for high-volume and reliability (used for longer than 5 years).

Product parameters of CCS811

Interface	I²C
Power supply voltage [V]	1.8 to 3.6
Power consumption [mW]	1.2 to 46
Size [mm]	2.7 x 4.0 x 1.1 LGA
Ambient temperature range [°C]	-40 to 85
Environmental humidity range [%rh]	10 to 95

Pin function of CCS811

VIN	Input power (3.3v to 5v)
3V3	3.3V output pin for external use
GND	Power ground
SDA	I2C clock pin
SCL	I2C data pin
WAKE	The wake-up pin of the sensor, which should be grounded to communicate with the sensor
RST	When grounded, the sensor resets itself
INT	This is the interrupt output pin, used to detect when a new reading is ready or when the reading becomes too high or too low

Function of CCS811

CCS811 has many functions, including metal oxide (MOX) gas sensor, microcontroller, analog-to-digital converter (ADC) and I2C digital interface. All these functions are integrated into a single miniaturized, 2.7mm×4.0mm, and 0.6mm land grid array (LGA) package, which is suitable for low-cost PCB technology.

• Detection of ethanol and dangerous gases：Based on its Micro-hotplate technology, CCS811 can be used to detect ethanol (alcohol) and hazardous gases such as carbon monoxide (CO) and various volatile organic compounds (VOC). This technology significantly reduces power consumption through a very fast measurement cycle and measurement time.
• Optimized low power mode：CCS811 supports a variety of low-power optimized measurement modes. The power consumption per minute is less than 1.2mW during active sensor measurement and less than 6μW in idle mode.
• Built-in microcontroller：CCS811 has a built-in microcontroller that manages the sensor drive mode, digital-to-analog converter measurement, and process raw sensor data to represent the equivalent carbon dioxide in the real world environment when using intelligent detection algorithms for gas detection (eCO2) level or total volatile organic compound (TVOC) measurement value.
  • The on-board processing function reduces the power consumption of the overall system and reduces the processing required by the main system.
• Digital interface： CCS811 supports a standard I2C digital interface compatible with the processor. Compared with using a separate gas sensor and microcontroller chip, a separate solution usually requires 2 or more additional components, and CCS811 can save equipment bill of materials cost and up to 60% of the circuit board area.

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TVOC and CO2 measurement with Arduino and CCS811 air quality sensor

To design an air quality monitoring system, we need some durable and reliable air quality sensors. Although there are many air quality parameters, the most important parameters are carbon dioxide and TVOC. Therefore, in order to measure CO2 and TVOC, we use the CCS811 air quality sensor.

Required materials:

• Arduino UNO development board
• CCS811 Air Quality Sensor
• Potentiometer (10k)
• LCD liquid crystal module 1602
• Breadboard
• Connecting wires

Circuit schematic

CCS811 air quality sensor

We use this sensor to measure or sense the TVOC and CO2 content in the environment and display the data on the LCD module 1602.

Code

#include <LiquidCrystal.h> #include "Adafruit_CCS811.h" LiquidCrystal lcd(12, 13, 8, 9, 10, 11); /// REGISTER SELECT PIN,ENABLE PIN,D4 PIN,D5 PIN, D6 PIN, D7 PIN Adafruit_CCS811 ccs; void setup() { lcd.begin(16, 2);   ccs.begin(); //calibrate temperature sensor while(!ccs.available());float temp = ccs.calculateTemperature();ccs.setTempOffset(temp - 25.0);}void loop() {if(ccs.available()){float temp = ccs.calculateTemperature();if(!ccs.readData()){int co2 = ccs.geteCO2();int tvoc = ccs.getTVOC();lcd.setCursor(0, 0);lcd.print(String ("CO2:")+ String (co2)+String(" PPM"));lcd.setCursor(0, 1);lcd.print(String ("TVOC:")+ String (tvoc)+String(" PPB "));lcd.print(String("T:"+String (int(temp)))+String("C"));delay(3000);lcd.clear();      }else{lcd.print("ERROR");while(1);}}}

In the project, you may use the professional and complete parts and PCBA services provided by Seeed. Click here for more details about the product ADS1115.

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Summary

And that’s all on getting to know CCS811! Hope that this article has helped you understand how to utilise CCS811 in your project, how it works and some details about it.

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