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Topic: Temp, Humidity CO2 sensor and library. (Read 50 times) previous topic - next topic


Just calibrate via fresh air which gives a value of about 380, maybe your in an area of high co2, I have a main road next to my house with a lot of traffic and average values were 420-450, are your values wildly out of range?


What program did you use to display the graphs of the temperature, humidity, co2?



I'm using a COZIRâ„¢ Wide Range Sensor, http://www.gassensing.co.uk/wp-content/uploads/2013/02/COZIR_-WideRange_-Datasheet_GSS.pdf, and I tried to use the cozir.h library as mentioned in the first post, but without success. Must I observe some particular attention? I'm tryng it with only usb cable attached to my Arduino UNO, perhaps I need an external 12V input for Arduino? I need only 3.3v to power the sensor.

I receive nothing from sensor, all zeroed values...

I tried also the sample from Cozir for this sensor to read byte-to-byte from serial but I receive only 255 and never 0x0A for end transmission.

please help me thx.



One often occuring problem with rs322 devices is that rx and tx need to be reversed. Did you try that?

Furthermore the sensor high bit is only 3.3Volt. The UNO needs at least 4.5 volt to recognize it as a HIGH signal. Check this with a voltmeter.
You might need a 3.3<->5 voltage converter for this.

Furthermore you could check if the analog out gives a (changing) voltage. Can you check?
Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)


Hi robtillaart

which pin I could check for analog voltage?

I have an external max3232 interface, which pins I must connect? I found that:

sensor tx: t1n
sensor rx: r1out
arduino tx: r1n
arduino rx: t1out

it's correct? I receive nothing :-(

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