This week, we present the Yocto-CO2-V2, successor of the Yocto-CO2, which has a sensor that is starting to be obsolete. Let's see what this is all about ...
The new Yocto-CO2-V2 is sufficiently equivalent to the Yocto-CO2 so that most applications designed for the old version still work with the new one, without even needing to be recompiled.
The brand new Yocto-CO2-V2
There are however some important differences that you should know about.
Differences from the Yocto-CO2
The CO2 sensor
The sensor now used is the brand new SCD30 from Sensirion which enables you to measure the CO2 rate between 0 and 40000ppm. Its accuracy is of 30ppm 3% between 400 and 10000ppm, but it is not specified outside this range. The sensor is based on the same NDIR measuring principle as the K30 of the Yocto-CO2. Therefore, it doesn't need any specific maintenance and is supposed to work without trouble for 15 years. By contrast, while the Yocto-CO2 measures the CO2 rate at 1Hz, the Yocto-CO2-V2 measures it only at 0.5Hz, that is one measure every two seconds.
Humidity, Temperature, and Pressure
While the Yocto-CO2 measures only the CO2 rate, the Yocto-CO2-V2 has additional sensors. It has a SHT31 embedded in the SCD30 to measure both the temperature and the relative humidity. The module also has an ICP-10100 sensor from TDK to measure atmospheric pressure. This pressure sensor is used, among other things, to automatically compensate the influence of the atmospheric pressure on the CO2 measure.
The massive size of the K30 forced us to adopt a somewhat misshapen format with the USB part soldered directly on the sensor. The relatively small size of the SCD30 allowed us to draw a PCB in the same format as other double-width modules. You can therefore use standard fixation points with the Yocto-CO2-V2.
The Yocto-CO2 consumes about 45mA with peaks at 500mA, which sometimes caused surprises for customers who used them with slightly too low power supplies. The Yocto-CO2-V2 is much less greedy: about 35mA in average with peaks at 90mA.
The recommended enclosure is the YoctoBox-CO2-V2-Transp. As the openings of the SCD30 are on the sides directly facing the enclosure vents, the lid doesn't have the perforations typical of the first version.
The Yocto-CO2-V2 in its enclosure
The Yocto-CO2-V2 is CHF 15 more expensive than the previous version, but this price increase hides a better CO2 sensor, as well as the equivalent of a Yocto-Meteo directly embedded in the module. If you had planned to buy a Yocto-CO2 and a Yocto-Meteo, you are a big winner :-)
In short, we can say that the Yocto-CO2-V2 advantageously replaces version 1, which will disappear as soon as our last stocks run out.