Breadboard - Indoor Air Quality Monitor


Hi @sneakthief
You can add your board to my server if you like :

Click top right and Add New Sensor Group.

Then in your core firmware set the hostname back to my server.
That will tell you if you are getting readings out anyway.


@Rockvole - Many thanks!

Giving it a whirl as we speak as my web hosting can’t get be accessed directly by an IP address. I suspect this is causing a problem with the script.

No idea why my VOC is reading zero. I’m currently getting 0.2V on it.

Both my VOC and Sewer Gas sensors are definitely working - I blew nail polish fumes on them and watched the voltages spike on my scope.

[EDIT] Is it possible if it’s calibrating in my flat that the reading is sending a zero value?[/EDIT]


Helpful tip: uncomment out this line in HttpClient.cpp in order to help out with serial debugging:

#define LOGGING


Yes, all your sewer readings are coming in as 0.

I’m confused what that “scale is too small to hold any ticks” error is, if I comment out :
$graph->yaxis->SetTickPositions(array(0,200,400,600,800,1000,1200,1400,1600,1800,2000), null);

In graphs/sewer.php then the tick positions are no longer fixed and then you can see the data.
I tried another one of my pages which had a full day of 0 values and that showed up fine.

I have a feeling that by tomorrow the graph will show your values. Of course they are all 0 right now,
which I guess will need some hardware troubleshooting.


If you read the tgs2602 variable it will tell you what the calibrated value is. It reads this value from EEPROM, so if you had some low values in there that could affect your reading. If you set it to the default of 340000 then you should get some values from the sensor (assuming the wiring is all good).

Your TGS2602 should be warm.


@Rockvole - As I mentioned, the TGS2602 is wired OK according to my digital storage oscilloscope.

When I flash the Tinker app, A0 is showing values of 430 on the TGS2602. When I blow on it, it bumps up to 500.

I’ll try reading the tgs2602 variable from the EEPROM later today.