Help to add co2 sensor to emonth


We're going to monitor about 20 zones in our facilities, but want to get CO2 values. 

We like a solution with emonth for sensors and raspberry for the base (we've been monitoring humidity and temp for some time with great success), and were wondering how to add a CO2 like this K30 from co2meter 

The problem we see is that this sensor operates at 4,5 or 5 volt and the emonth is powered with 3v.

There is any option or it is safe to power the emonth with a 5 volt battery?

My intention is to power it using the pin #1 next to dht22 socket. It is possible? Or maybe I must solder two pin headers into the mini usb hole below the battery holder?


Robert Wall's picture

Re: Help to add co2 sensor to emonth

You can supply it with 5V on the USB connector, but if you're using the analogue output from your sensor, you'd need to divide it down to 3.3 V max. as that's the maximum input to the ADC.

Circuit diagram & PCB layout is on the Wiki.

DavidF's picture

Re: Help to add co2 sensor to emonth

Ok, many thanks, I've seen the layout now.

I'm planning to read using either i2c or software serial, but thanks on the ADC level.

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