ccs811 Archives

In this example we will connect a CCS811 gas sensor to an STM32 Nucleo – we will write the code in the Arduino IDE

CCS811 is a low-power digital gas sensor solution, which integrates a gas sensor solution for detecting low levels of VOCs typically found indoors, with a microcontroller unit (MCU) and an Analog-to-Digital converter to monitor the local environment and provide an indication of the indoor air quality via an equivalent CO2 or TVOC output over a standard I2C digital interface.

Features

Integrated MCU
On-board processing
Standard digital interface
Optimised low power modes
IAQ threshold alarms
Programmable baseline
2.7mm x 4.0mm LGA package
Low component count
Proven technology platform

Specs

Interface	I²C
Supply Voltage [V]	1.8 to 3.6
Power Consumption [mW]	1.2 to 46
Dimension [mm]	2.7 x 4.0 x 1.1 LGA
Ambient Temperature Range [°C]	-40 to 85
Ambient Humidity Range [% r.h.]	10 to 95

Parts List

Name	Part Type
CCS811	CJMCU-811 CCS811 Air Quality Gas Sensor
STM32 Nucleo	STM32 Development Board NUCLEO-F446RE, STM32 STM32F446RET6 MCU, supports Arduino
Connecting wire	Free shipping Dupont line 120pcs 20cm male to male + male to female and female to female jumper wire

Layout

Remember and connect WAKE to gnd

Nucleo and CCS811 layout

Code

Again we use a library this is the adafruit one – you can use the library manager and add this.

And this is the out of the box example

[codesyntax lang=”cpp”]

#include "Adafruit_CCS811.h"

Adafruit_CCS811 ccs;

void setup() 
{
  Serial.begin(9600);
  Serial.println("CCS811 test");
  
  if(!ccs.begin())
  {
    Serial.println("Failed to start sensor! Please check your wiring.");
    while(1);
  }
  
  //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()){
    Serial.print("CO2: ");
    Serial.print(ccs.geteCO2());
    Serial.print("ppm, TVOC: ");
    Serial.print(ccs.getTVOC());
    Serial.print("ppb Temp:");
    Serial.println(temp);
  }
  else
  {
    Serial.println("ERROR!");
    while(1);
  }
}
delay(500);
}

[/codesyntax]

Output

Open the serial monitor – this is what I saw. The higher CO2 level was when I breathed on the sensor

CO2: 400ppm, TVOC: 0ppb Temp:25.92
CO2: 400ppm, TVOC: 0ppb Temp:25.52
CO2: 400ppm, TVOC: 0ppb Temp:20.47
CO2: 400ppm, TVOC: 0ppb Temp:19.33
CO2: 400ppm, TVOC: 0ppb Temp:23.47
CO2: 400ppm, TVOC: 0ppb Temp:25.00
CO2: 400ppm, TVOC: 0ppb Temp:26.32

Links

ccs811 datasheet

CJMCU-811 CCS811 Air Quality Gas Sensor

In this example we will connect a CCS811 gas sensor to an STM32 Nucleo and the code example will be written in the MBed compiler, lets look at the sensor

Features

Specs

Interface	I²C
Supply Voltage [V]	1.8 to 3.6
Power Consumption [mW]	1.2 to 46
Dimension [mm]	2.7 x 4.0 x 1.1 LGA
Ambient Temperature Range [°C]	-40 to 85
Ambient Humidity Range [% r.h.]	10 to 95

Parts List

Amount	Part Type
1	CJMCU-811 CCS811 Air Quality Gas Sensor
1	STM32 Development Board NUCLEO-F446RE, STM32 STM32F446RET6 MCU, supports Arduino

Schematics/Layout

Remember and connect WAKE to gnd

stm32 nucleo and ccs811 sensor

Code

Again we use a library this is the adafruit one – you can use the library manager and add this.

And this is the out of the box example

[codesyntax lang=”cpp”]

#include "mbed.h"
#include "CCS811.h"


Serial pc(USBTX, USBRX);

#ifdef TARGET_UBLOX_EVK_ODIN_W2
CCS811 ccs811(PF_0, PF_1);
#else
CCS811 ccs811(I2C_SDA, I2C_SCL);
#endif


uint16_t eco2, tvoc;


void CCS811Callback(void)
{

    ccs811.readData(&eco2, &tvoc);

    pc.printf("eCO2 reading :%dppm, TVOC reading :%dppb\r\n", eco2, tvoc);

}


int main()
{
    ccs811.init();
    wait(1);

    while(1) {
//        ccs811.readstatus(); //0x90 reports everything working, 0x98 measurement ready to be used
        wait(1);
        CCS811Callback();
        wait(1);
    }
}

[/codesyntax]

Output

Open Teraterm and connect to the assigned port of the STM32 nucleo

You should see something like this

ccs811 output

Links

ccs811 datasheet

ccs811

STM32 Nucleo and CCS811 sensor Arduino example

Parts List

Layout

Code

Output

Links

STM32 Nucleo and CCS911 sensor MBed example

Parts List

Schematics/Layout

Code

Output

Links