PRIORITY CLAIM

This application claims the priority benefit of Italian Application for Patent No. 102019000004149, filed on Mar. 21, 2019, the content of which is hereby incorporated by reference in its entirety to the maximum extent allowable by law.

TECHNICAL FIELD

The description relates to sensors such as wireless and battery-free sensors for application, for example, in home automation systems and/or wireless sensor networks.

Such sensors may be, for instance, light (intensity) sensors, electromagnetic power sensors (for example, for measuring electromagnetic pollution), vibration sensors, temperature sensors.

For instance, exemplary embodiments can relate to wireless, battery-free light sensors with (solar) energy harvesting capabilities, for example for the use with twilight switches.

BACKGROUND

A wireless sensor network (WSN) may comprise a certain number of spatially dispersed and dedicated sensors for monitoring the physical conditions of an environment. For instance, sensors in a wireless sensor network can measure environmental conditions like temperature, sound, pollution levels, humidity, wind, light intensity, vibrations, electromagnetic pollution, and so on. The dispersed sensors may communicate the collected data to a central processing unit, which may perform organization and/or processing of the data.

Thus, sensors in a wireless sensor network—for example, as increasingly used in home automation systems—may involve collecting data and sharing the collected data (with a central processing unit, and/or amongst themselves) wirelessly.

Taking advantage of their wireless communication capability, sensors in a wireless sensor network may be positioned in places which are uncomfortable to reach, for example because no cables are required for data communication and power supply.

On the other hand, placing sensors in hard-to-reach locations may render maintenance operations somehow difficult to be carried out. For instance, battery-supplied wireless sensors may involve substituting the power source at regular time intervals, thus requiring troublesome service operations.

An exemplary type of wireless sensor in the field of home automation and “green” (such as, energy-efficient) buildings are light sensors, for example for the use with twilight switches.

A twilight switch is a device which may comprise a light sensor to trigger a relay switch. Typically, twilight switches are biased through the main power supply and need to be wired. However, this solution may imply low flexibility of installation.

Wireless twilight switches are also available in the market. Even if wireless twilight switches may provide higher flexibility of use, they are typically battery-supplied and involve a dedicated light sensor to measure light intensity. The presence of a battery involves troublesome maintenance operations as discussed above, and may also involve a limited flexibility for the placement of the sensor.

Examples of wireless, battery-supplied twilight switches are the devices available to the public with the trade designations of Nexa LBST-604, ElkoEP RFSOU-1, and Home Easy HE404EU.

Such known wireless, battery-supplied devices, despite providing some improvements concerning the flexibility of use (during and after installation) if compared to wired devices, still have many drawbacks concerning service and maintenance operations.

Similarly, also other types of sensors (for example, vibration sensors, temperature sensors, etc.) may be biased through the main power supply and may need to be wired.

Despite the extensive activity in the area, further improved solutions are desirable.

For instance, solutions are desirable for providing sensors which have, at the same time, measuring capabilities and energy harvesting capabilities, for example for realizing battery-free and so-called “set-and-forget” sensor nodes. Set-and-forget sensor nodes may be inherently (almost) maintenance-free, thereby facilitating IoT (Internet-of-Things) devices being virtually ubiquitous.

Specifically, solutions are desirable wherein an energy-harvesting electric generator (for example, a photovoltaic generator such as a photovoltaic cell, a radio-frequency energy harvester, a vibrational energy harvester, a thermoelectric generator, etc.) may provide at the same time power supply functionality and measurement functionality of a sensor. Such sensors may thus be wireless and battery-free.

There is a need in the art to contribute in providing such improved solutions.

SUMMARY

According to one or more embodiments, a sensor (for example, a light sensor) provides the improved solution.

One or more embodiments may relate to a corresponding system, such as an “intelligent” twilight switch or a wireless sensor network.

One or more embodiments may relate to a corresponding operating method.

One or more embodiments may, for instance, facilitate providing light sensors for measuring light intensity, wherein a photovoltaic generator in the light sensor provides both power supply and light intensity measurement capabilities of the sensor. Light sensors according to one or more embodiments may thus be wireless and/or battery-free.

