One of the vertical use cases that has been implemented in the #SmartME project
is the collection of city environmental monitoring data in a standard open data format.
We exploited CKAN, an open source data portal software, to store and visualize the
Asynchronous plugins are used in this application for sampling environmental data
and sending it to the CKAN datastore. The plugins run on top of Arduino YUN boards
deployed in the Messina urban area.
The Arduino YUN is an embedded board based on the Atmel ATmega32u4 micro-controller
and the Atheros AR9331 System-on-a Chip. Linino OS, a Linux distribution based on
OpenWrt, runs on the Atheros MIPS processor, also supporting microcontroller-exposed
interfaces to General Purpose I/O (GPIO) pins. The board has built-in Ethernet and
WiFi support, a USB-A port, micro-SD card slot, 20 digital I/O pins (of which 7 can be
used as PWM outputs and 12 as analog inputs), a 16 MHz crystal oscillator,
a micro USB connection, an ICSP header, and 3 reset buttons.
In order to host a set of low-cost sensors, the YUN board has been equipped with a
Tinkerkit Shield. In particular, a Tinkerkit thermistore, Ldr, and Mpl3115 have
been employed as temperature, brightness, and pressure sensors, respectively.
A Groove MQ9 is installed as CO sensor, to obtain information about air quality.
Finally, a Honeywell HIH-4030 has been selected as humidity sensor while an Arduino
KY38 captures the environmental noise level.
Using the ideino-linino library, plugins periodically sample the voltage levels
of the pins to which sensors are connected. Such voltage samples are then elaborated
to obtain the environmental data and finally sent to CKAN together with a timestamp
and the geographical position of the node.