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mariusebastian f96cf2abc6
Debug info and temperature update
Prevent "...Status maybe not OK.." from always being printed when debug is on.
Changed the is !isReady check to isPreHeating when getting the latest temperature. The isReady check prevents the function from returing the pre stored temperature within MHZxxx_RESPONSE_TIME after the UART data has been requested. This is an unnecessary restriction.
2018-09-24 12:12:02 +02:00
examples/MH-Z19B Removed duplicated example. 2018-09-05 00:00:31 +02:00
.gitattributes Initial commit 2018-04-22 11:36:51 +02:00
.gitignore Added isPreheating and isReady to MHZ.h and reformatted. 2018-07-07 12:59:32 +02:00
keywords.txt Use correct field separator in keywords.txt 2018-07-17 07:29:47 -07:00
library.properties Updated description. 2018-09-07 00:03:33 +02:00
LICENSE Initial commit 2018-04-22 11:36:51 +02:00
MHZ.cpp Debug info and temperature update 2018-09-24 12:12:02 +02:00
MHZ.h Implemented isPreHeating and isReady. 2018-07-07 16:05:40 +02:00
README.md Update README.md 2018-09-04 23:45:04 +02:00

MH-Z14A, MH-Z19B CO2 ... Module

Arduino implementation for MH-Z CO2 sensors such as MH-Z14A, MH-Z18B (as I didn't find all info in one place).

The sensor is available for ~20 bucks at the usual places.

Implementation

See example.

PPMuart: 602, PPMpwm: 595, Temperature: 23

Implementation details

C ppm = 5000 * (T_high - 2 ms) / (T_high + T_low - 4ms)

The implementation is mostly based on https://forum.arduino.cc/index.php?topic=525459.msg3587557#msg3587557

Resources:

Datasheet: http://www.winsen-sensor.com/d/files/infrared-gas-sensor/mh-z19b-co2-ver1_0.pdf

More info about the sensor: https://revspace.nl/MHZ19

Further reading:

(russuian, but google translate does a good job)