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maarten-pennings / CCS811

Arduino library for the CCS811 gas sensor for monitoring indoor air quality.
MIT License
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[Question] Modes, Burn-In - Several Questions #59

Closed DerPicknicker closed 2 years ago

DerPicknicker commented 3 years ago

Good afternoon,

I have discovered your library and read your posts and already learned a lot...Thank you for your detailed insights. But I still have some (probably simple questions for you).

I have already looked into the datasheet and found the modes there. I have a few questions:

Do you have to use firmware 2.0.x to get useful results or is it enough to burn the sensor with firmware 1.0 for 48 hours?

Are there any tips under which conditions the burn-in has to take place?

Thank you for Reading my Post.

Best Regards!

DerPicknicker commented 3 years ago

EDIT:

Now I can answer some of my Question :

In this Line you set the Mode, this must happen in the Setup() Function. ccs811.start(CCS811_MODE_1SEC); // CCS811_MODE_IDLE (Mode0); CCS811_MODE_1SEC (Mode1); CCS811_MODE_10SEC (Mode2); CCS811_MODE_60SEC (Mode3)

My other Questions aren’t answered yet. I hope @maarten-pennings have some time to answer the other ones :)

maarten-pennings commented 3 years ago

Can the sensor sleep for 5 minutes or must it be permanently active?

As the datasheet explains: _After writing to MEASMODE to configure the sensor in mode 1-4, run CCS811 for 20 minutes, before accurate readings are generated.

So, each time you switch mode (which you must if the device is powered on) you have to condition the device for 20 min. For lowest power, put the device in 60s mode.

Are the values inaccurate if it has not measured anything for too long?

What do you mean with "has not measured"?

Firstly, the device must be running at least 20 min before it is conditioned. Secondly, the reading that you get is relative to the cleanest air the device has seen in the last 24hr. See "Automatic Baseline Correction" in the datasheet.

DerPicknicker commented 3 years ago

After some time the Results of the measurements are totally weird... Overnight I measured 1k-4k ppm. The Window was opened at the Sensor was 20cm away from the Window... I ordered a new One to check if my first Sensor was defect. And if not I will test it again with an BME280 for the Temperature Compensation.