Hello,
I am working on a project that includes the FC22 MQ135 gas sensor.
I have went through pages and pages and yet did not find the real answer.
Anyways, my problem is the reading and calibrating. I get the results as i
use the analogRead() and also the MQ135.h library, but don't know which one is the
correct reading... It's confusing for me as a novice in Arduino programming.
Also the calibrating, on this type of sensor there is a little screw that can be
tinkered around, but i did not found the proper documentation for it (only shopping sites).
Of course, there is the MQ135 datasheet, but the FC22 is not explained.
here is the MQ135.h code
#include "MQ135.h"
MQ135 gasSensor = MQ135(A1);
int ppm = gasSensor.getPPM();
void setup() {
Serial.begin(9600);
}
void loop() {
float rzero = gasSensor.getRZero();
float ppm = gasSensor.getPPM();
Serial.println(ppm);
delay(5000);
}
And the readings are like
...
11.54
11.42
11.54
11.54
...
The reading with the analogRead() code:
...
176
175
172
175
...
Thanks in forward!
Did you ever find any answers on the FC-22-I? I just bought one and they are very confusing. I read that they need to be burned in for 12-24 hours, then you need to work out what their "zero" reading is, because all sensors might be different.
When I'm reading values from getRZero() and getPPM(), the values returned fluctuate a lot. I'm trying to work out how sensitive to change they are. I'm also trying to figure out how to use the adjustment potentiometer screw at the back. Like you I got no documentation.
sikinchara:
Also the calibrating, on this type of sensor there is a little screw that can be
tinkered around, but i did not found the proper documentation for it (only shopping sites).
Of course, there is the MQ135 datasheet, but the FC22 is not explained.
This is a question I have seen several times in google. The little screw is just a alarm link to a second LED, if the gas goes up the led turns ON. You can change sensibility of this alarm by moving the screw.
If anyone needs more help with the MQ135... I did this repository> GitHub - Ravenneo/CO2-sensor: Lab CO2 Sensor
Is made by a noob (me) so I am also open to change whatever is necessary.