Last year, I made a simple breadboard with a 8266 MOD 12-F, connected to CCS811 eCO2 / eVOC sensor. It worked on power on with this setup in ESPHome: captive_portal: # CCS811-Sensor für CO2-Messung i2c: sda: 4 scl: 5 sensor: - platform: ccs811 eco2: name: "CCS811 eCO2-Wert" tv…

What you get on esphome logs? Also, that sensor has long warmup time.

Thanks for all the information and advice. I’m well aware about measurement methods concerning CO2. I’ve built true CO2 measurement projects using the MH-Z19B, which is working fine. I have access to a professional CO2 meter, used by firefighters. The deviation is 10 - 20% … not much worse. Using a…

[image] Michael5411: Got co2=400 ppm, tvoc=0 ppb, baseline=0x66AD Let it run for half an hour in clean air and observe what baseline you get. Then insert that on your code like described on docs: [image] CCS811 eCO_2 and Volatile Organic Compound Sensor Instructions for setting u…

I’ve taken my sensor & breadboard outdoor for a whole day in fresh air. While everything was still connected I took the LOG and found a baseline figure of 0x66AD after 20 hours. I put the baseline code into the ESPHome setup script and installed it. After that I got a new log output showing that t…

Try with default update interval and make sure wake-pin is connected to gnd.

Thanks again for your kind advice. I’ve checked each single pin. WAK = 0 V, ADR = 0 V (means address is correct), power =3.33 V, GND =0 V … etc. No effect. Same result. I’m waiting now for the replacement of the sensor, which is on it’s way to me. I’ll give you an update, asap.

[image] Michael5411: power =3.33 V You power the sensor from esp 3.3V pin to CCS811 VIN pin, right? 3V3 pin is output…

Hi dear ESPHome experts, I got the new sensor. It’s in the setup mode at the moment. Every minute, I get a new log output with a new baseline. I will run it (at the window in front of my office), until I have a stable baseline output. At the moment „baseline“ is commented out. One more question: I…

Id is esphome sensor id, not HA entity id. sensor: - platform: homeassistant name: "Temperature Sensor From Home Assistant" entity_id: sensor.temperatur_az_touch id: temp_az # whatever you want to name it [image] Home Assistant Sensor Instructions for setting up Home Assi…

CCS811 integration in ESPHome delivers only default value 400ppm eCO2

ESPHome

Edwin_D (Edwin D.) December 8, 2025, 10:05am 3

I cannot tell you what is wrong. What I can tell you is that, even when working, this sensor will tell you nothing about CO2 levels. eCO2 values are based on wrong assumptions.