MICS 6814


I have a weeny problem with this sensor:


I did not find any library or example code. There are some, but they are written for this MICS 6814 which lays on some board that is converting analog output to i2c output. For example:


and library for this:


My questions: Does anyone know some library or code for this "raw sensor"? OR Is possible to use library, which I mentioned before, if I buy some AD -> I2c converter?




You don't need a library for that sensor. Wire it up according to the schematics in the data sheet, and measure voltage values using the Arduino ADC.

If you really are planning to use the "raw sensor", be certain to follow instructions:


Read the following instructions carefully before using the MiCS-6814 described here to avoid erroneous readings and to prevent the device from permanent damage.

•The sensor must be reflow soldered in a neutral atmosphere, without soldering flux vapours.

•The sensor must not be exposed to high concentrations of organic solvents, silicone vapours or cigarette-smoke in order to avoid poisoning the sensitive layer.

•Heater voltage above the specified maximum rating will destroy the sensor due to overheating.

•This sensor is to be placed in a filtered package that protects it against water and dust projections.

•SGX sensortech strongly recommends using ESD protection equipment to handle the sensor.

you say I do not need library. I have written some basic code, but i am getting silly values. Now I will have stupid question: What I should do? And next: If I somehow programme it, how I get other values, which are mentioned in datasheet, like methane, ethanol, hydrogen? (In attached schematic there are only three values comming out).

mics6814.ino (316 Bytes)

First, you need to understand how the sensor works. I recommend to study the data sheet very carefully. Operation is very similar to the operation of the MQ sensor series, which is an additional source of information.

Then, if you have questions, please read and follow the directions in the "How to use this forum" sticky before posting.

i am getting silly values

Did you follow the instructions in the data sheet for mounting and soldering the sensor in a neutral atmosphere?

@Iridium1944 hallo have you fixed your problem?

"how I get other values, which are mentioned in datasheet, like methane, ethanol, hydrogen?"

Because also i have the same questions Have a nice day Lorenzo @gpb01 ho scritto solo in due posti diversi poiche stamane sul forum italiano ho ripreso una vecchio post, senza così ulteriormente aprirne un secondo, sperando così di non aggravare con altri post il forum. Ho notato che è stato cancellato di netto! Chiedere solo informazioni senza aprire ulteriori post non mi sembrava così grave, oltretutto il posto sul forum in inglese non aveva avuto soluzione....


maybe you forgot pullup-resistors? Do you use the MiCS-6814 on the purple adapter board CJMCU6814? Then you may add an eg 47k ohm resistor from the analog Input (A1 in your sketch) to Vcc (5V or 3,3 V, depends on your arduino). Then you should get other measurment than the 0-values. BTW: the sensor needs some time to heat up. And I'm not sure about it's stability over time. I've no experience with it yet.

Hi there,

Just for future reference, and maybe help people that might stumble into the same problems I did when dealing with CJMCU-6814 / MICS-6814, this is a post I just did in a different thread about the same topic.


Cheers, Feu