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XylenC4 / CO2-ESP32

Arduino CO2 and Temperature logger based on BOSCH BME280 and Winsen MH-Z19B
MIT License
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Question #3

Open Alfourbe opened 5 years ago

Alfourbe commented 5 years ago

Hi, sorry to open an issue, I have just 2 questions but don not see how to ask without opening an issue. I wonder if the fan could have an impact on the pressure reading in the box. Did you test with and without fan to check the difference?

I received my Mzh19 since, and I dont' want to keep the fan on all time. I will put a transistor to switch it on just one minute before reading co2 every 15-20 min, do you think it can be an issue with the reliability of co2 reading? Thank you

Alfourbe commented 5 years ago

image FYI I finnally make it work, thanks to you, it was more complicated tha expected as I used parts I already have (ESP8266, BMP180... and I had to change and adapt all libraries but here we go Happy :), thank to you

XylenC4 commented 5 years ago

nice to see you was able to run and modify it for ESP8266. I'll have some issues with a thermal drift which is caused by my ESP32. At the moment i do not use a deep sleep but this will be changed in the future. Have you done any tests regarding the pressure yet? There is no "warmup" time specified in the datasheet of the MH-Z19B.

Alfourbe commented 5 years ago

HI, from l what I saw in the Datasheet, it is 3 min preheat time and response time less than 60sec, that's why I wanted to read pressure, switch on fan, wait 1 min, read CO2, and switch off fan. I think I will also start WIFI only when connecting to Thingspeak, and switch it off the rest of time. For pressure I get a reading with bmp180 but I don't have humidity so I ordered a BME280 and as I didn't print the enclosure yet, I didn't test if it have an impact on pressure reading. I am surprised you have thermal drift with the Fan switch on, You can not move it away from ESP32? I am also plan to add a BH1750 to dim the OLED, it is in my bedroom now and at night it is really too brightness. I will add a RGB led also to make a green/orange/red visual alert, and it will be dimm to with light sensor.. Your code is clear, and I like that you split for each component, that make easy to modify and adapt to my needs. Let's wait for the material to arrive from aliexpress....