CJMCU-811 CCS811 Carbon Monoxide CO VOCs Air Quality Digital Gas Sensor

https://revspace.nl/CJMCU-811

pins

    VCC this is directly connected to the IC (there is no voltage regulator on board), connect this to 3.3V
    GND to ground obviously
    SCL signal from I2C
    SDA signal from I2C
    WAK this needs to be low (!) in order for the chip to be active
    INT can be left unconnected
    RST can be left unconnected
    ADD can be left unconnected. It has a 10k pull-down to GND, setting the I2C address to 0x5A.

firmware upgrade

https://github.com/maarten-pennings/CCS811/tree/master/examples/ccs811flash

dpavlin@nuc:~/Arduino/libraries$ git clone https://github.com/maarten-pennings/CCS811

Wiring for ESP8266 NodeMCU boards: VDD to 3V3, GND to GND, SDA to D2, SCL to D1, nWAKE to D3 (or GND)

Serial output with sensor out of (china) bag:

setup: Starting CCS811 basic demo
setup: ccs811 lib  version: 12
setup: hardware    version: 12
setup: bootloader  version: 1000
setup: application version: 1100
CCS811: waiting for (new) data
CCS811: waiting for (new) data
CCS811: eco2=0 ppm  etvoc=0 ppb  
CCS811: eco2=0 ppm  etvoc=0 ppb  
CCS811: eco2=0 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb  
CCS811: eco2=400 ppm  etvoc=0 ppb