I wanted to use a BME680 with the ESPHome component that uses the BSEC library (klick) to monitor the IAQ value with my HomeAssistant. Since the BME688 was advertised as a drop in replacement and offered some cool new features i got the 688 instead.
I set everything up, sensor readings where coming in and i put the senor in my bedroom. Since several days the IAQ quality indicator stays at "uncertain" and also the readings seem somewhat odd (going up when opening the window and going down when sleeping next to the sensor with closed windows).
Because of this i checked the version of the used BSEC in the ESPHome Component, it is 1.6.1480.
Thanks very much in advance!
I had the same problem.
Check the raw resistance value, in my case that value was abnormally high when using BME688 with BSEC 1.x (Mega ohms order).
Couldn't finde the cause, so just kept using BME680.
In BSEC 2.0 didn't had that problem with BME688 but many others... (so kept using BME680 with BSEC 1).
Had a problem that when using HIGH PERFORMANCE to get gas estimates and IAQ..some times the library just hanged for MINUTES (kept giving temperature, humidity and pressure values). Couldn't achive a constant time between gas values aquisition.
Other problem I had was that I wanted a librery were I could user BME688 and BME680 (just IAQ values) sensor without having to change the code (not all the code at least). Wanted this because BME680 stock is so not stable.
Couldn't get BME680 working correctly with BME2.0 (even if that library is supposed to be for BME68x).
I guess the library is very new and still needs a bit of work... If it was open source it would be much easier to work with and fix...
I guess al the problems I mentioned above have a solution. At the moment I had them, couldn't solve it fast enought so went back to BME1.x as the moderators recommended for BME680. So now my project depends on the availability of BME680 sensor which is very unstable.
Another factor to "go back" to BME680 (only BSEC 1.x) was that it resulted impossible to get BME688 development board in latin america. It was just available in a few stores in germany when I checked. My project just needed IAQ values at the beggining, but wanted to sell an "extra feature" in future updates (OTA).
Hope this helps you! I do not mean to criticize BSEC 2.x or anything. Just wanted to share my experience. Both BSEC 1 and BSEC 2 are amazing libraries, but maybe BSEC 2 still need a little more work to acchive all it says it can do (in a "plug and play" manner at least).