This week, we are happy to announce the availability in our on-line shop of two new USB sensors: the Yocto-Meteo, that superseeds the Yocto-Humidity, and the Yocto-Light, that was used in last week project. Let's take this chance to tell you more about them.
The Yocto-Meteo is one of our most sophisticated sensors. We have chosen to bet on component quality and robustness. As humidity and temperature sensor, we chose the SHT21 sensor, from Sensirion. There are many other humidity sensors, as the ones you can find in most "made in China" mainstream products, but the quality is just... something else. The SHT21 is a numeric sensor, factory calibrated and with a predetermined error margin. The fact that the measures are transmitted using a numeric protocol guarantees that the measures are not biased by electromagnetic emissions, and also allows you to move the sensor far away (we have tested sensors up to 25 meters away from the module) while keeping most of the electronics safe. Also, whereas mainstream humidity sensors typically need 10 to 30 minutes to take into account a quick change of ambient humidity, the SHT21 only needs 8 seconds. And it only requires a simple shield to resist outside conditions, as demonstrated by our little weather station. For applications requiring a direct contact with water, it is even possible to use the SHT21 with a little protective cap and a sealing ring, which still allow for 30-second latency measurements while keeping the sensor protected from immersion into water.
The atmospheric pressure sensor MPL115A2 that we added is very beneficial to meteorological applications. It is also a numeric sensor, temperature-compensated, with a good precision (1mbar absolute precision). On this topic, don't get trapped by the misleading precision values often announced by some vendors. Indeed, it is often easier to tell about the sensor resolution (or the relative precision), rather than to give the real absolute precision of the sensor, which is how much the sensor is really off the measured physical value.
The USB humidity, temperature and pressure sensor Yocto-Meteo
To summarize, the Yocto-Meteo should allow you to build your very own weather station to optimize your garden watering or your house heating based on the weather!
The Yocto-Light is a simpler product, but still based on the same principle: a good numeric sensor made by OSRAM, the SFH 5712, that can be moved away without risk of altering the measurement. The light sensitivity zone is a tiny square of 0.4mm. The sensitivity to light is very similar to human eye, making it suitable for applications such as automated lighting control applications, or for photography.
The USB ambiant light sensor Yocto-Light
Beside these new products, we are also releasing new versions of the development tools. A new version of the VirtualHub is now available, including several bug fixes, and you will shortly get an updated version of the development library as well, including various enhancements, in particular for connecting to Yoctopuce sensors through TCP/IP network, and to fix some occasional issues on Linux.
Have a good week !