最近開始監控co2 client 收回來的值是否正常

發現一個問題

有几台client在早上6點開完几後是正常

但過了一段時間(不一定多久)

就會發生當几的問題

此時不管再怎麼重開都沒用

本來一直是從cjmcu-8118有問題的方向去想

想直接買新的來換

忽然看到之前參考的視頻說明有一段話

Problem: Measured temperature from HDC1080 is higher than expected (up to 3 C)

Cause: gas sensor generates heat and this affects HDC1080 sensor

Solution: switch CCS811 sensor to low-power pulse heating mode (mode 2 or 3) and measure temperature/humidity before the pulse

再查了一下文件

Modes of Operation⇠

The CCS811 has 5 modes of operation as follows:

    Mode 0: Idle, low current mode

    Mode 1: Constant power mode, IAQ measurement every second

    Mode 2: Pulse heating mode IAQ measurement every 10 seconds

    Mode 3: Low power pulse heating mode IAQ measurement every 60 seconds

    Mode 4: Constant power mode, sensor measurement every 250ms. This mode is meant for factory testing. The ALG_RESULT_DATA is not updated, only RAW_DATA; the processing must be done on the host system.

依照不同的取樣頻率來調整不同的mode (加熱模式)
看起來如果不是短時間頻繁的要check值

使用 mode 3 應該就可以了 而且可以減少發熱的問題

再看一下目前程式使用的是mode 2

今天調成mode 3

觀察了一天

沒有再發生當几的情況

再持續看看還會不會有問題

https://www.espruino.com/CCS811

https://www.youtube.com/watch?v=XNtbV1Z5W3o&t=193s