readings from Sparkfun CCS811+BME280

Sensors Environmental
1

Hi choungyeol.

First, I observed the sensor values increased rapidly up to 6000 ppb, as shown in figure 1. This result makes me wonder why the value exceeds the upper limit. As far as I know, CCS811 detection ranges from 0 to 1189 ppb and if it exceeds the limit, the value is clipped. Shouldn’t the value remain same once it went beyond the limit? Or Is the sensor capable of detecting the wider range?

My guess is that the accurate range is from 0 - 1189 ppb but the sensor can measure above that. The data sheet does mention values above 1189 should be clipped, but it’s possible that you may need to configure the chip to enable clipping. SparkFun doesn’t make the CCS811 chip, we just make the board that it’s on and we don’t have detailed knowledge on the inner workings of the chip. You might want to try contacting the manufacturer ([AMS) to see if they have any insight as to what might be going on.](https://ams.com/)

2

I too have had increasing readings on my CCS811 sensor. I have run numerous tests with the basic example and the upward creep does not occur. Suspecting a library conflict, I removed functionality from my sketch systematically, OLED, aREST, compensation, etc. Finally, I removed the WiFi.begin(); statement and the creep stopped. This makes no since to me. Could WiFi be jamming the chip, unlikely.

I would like other’s experiencing readings creep to try this.