Patent Description:
Interactive systems using living plants as interfaces to activate actions on devices are known in the state of the art. For example, document <CIT> discloses a system with a detection module configured to measure changes in the impedance of a plant when a person approaches to it or touches it. After that, the system sends an order to a device to provide an action. Specifically, this system correlates the measured impedance curve with one or more predefined impedance curves, where each predefined impedance curve corresponds to a particular action performed by the user. Depending on the correlation obtained, the system orders one or another action.

In contrast, document <CIT> discloses a system comprising a detection module that forms an RC oscillation circuit with a plant, which is isolated from the ground. A control chip sends signal pulses to the detection module and determines whether a person is touching the plant or not based on the charge time and the discharge time of the RC oscillation circuit.

An interface system comprising a plant is also known from document <CIT>.

However, living plants change shape and size, or the substrate they are planted on may vary in condition, making it difficult to keep detection modules in accurate calibration and make detections reliable over time.

Therefore, there is a need to provide a reliable system for providing accurate interpretations of user's interactions with a living plant.

The aim of the present invention is to provide an interface system according to independent claim <NUM> for solving the previously cited necessity.

According to a first aspect, which does not form part of the present invention, it is provided a detection module for detecting capacitance variations in a plant, comprising:.

The present detection module is characterized in that it comprises a user-accessible potentiometer in electrical communication with the control unit, the potentiometer being configured to adjust said threshold value. For example, the potentiometer's adjustment can be performed according to the natural capacitance established by the plant in its location. Thanks to this configuration, the detection module can be calibrated in an easy way when installed and permits feasibly detecting a capacitance change when a subject becomes electrically coupled to the plant -e.g., by touching it. Once the detection module has been calibrated using the potentiometer, the control unit may adjust any drift in the measured signal.

As it can be inferred, the detection module may comprise an input port for receiving a communication port from another detection module, and producing a series connection by several detection modules and the external devices.

In a preferred example of said detection module, at least one of said electrodes and/or said potentiometer is arranged at the end of a shielded wire, in order to avoid electrical noise and other interferences from affecting the measured values.

In another preferred example, the control unit is configured to apply a moving average algorithm to the voltage values provided by the capacitive sensors during a predetermined time interval, so an average voltage value is calculated. Said average voltage value is the one to be compared with the threshold value. When measured with an electrode, the natural capacitance from a plant is a quite instable value over time, which is turned into voltage oscillations and peaks by the capacitive sensor. Thanks to this configuration, the control unit obtains a more stable value to compare with the threshold value, and the plant-subject coupling detection becomes more reliable.

In another preferred example, the control unit is further configured to measure a dwell time for which the processed voltage values rate above the threshold value and, if said dwell time is lower than a predetermined duration, avoid sending the corresponding control signal. In this example, the control unit is able to measure the time the processed voltage values -averaged or not- are above the threshold value, and interpret that there has been a coupling between a subject and the plant when said time is longer than a predetermined minimum duration. In other words, the control unit is configured to send the corresponding order only when the trigger situation of a processed voltage value above the threshold value has a minimum duration. This minimum duration can be set between <NUM> milliseconds and <NUM> milliseconds, preferably <NUM> milliseconds. When the duration is less than said set time, the control unit is configured to discard the supposed coupling as a false positive. If the duration is longer than the set time, the control unit is configured to accept the coupling as true and activate the corresponding command.

During the coupling time, the voltage value may fluctuate and unintentionally fall below the threshold value. Therefore, in another preferred example, the control unit is configured to, after been measured a dwell time higher than a predetermined dwell duration and been detected that the processed voltage values dropped below the threshold value, measure a holding time for which the processed voltage values rate below the threshold value and, if said holding time is lower than a predetermined holding duration, avoid sending a new corresponding control signal. In other words, the control unit is configured to measure the time in which said processed voltage values are below the threshold value after being accepted a coupling as true, in order to know if a drop is due to an involuntary oscillation or if it is due to the user having stopped being coupled to the plant and being coupled again. The minimum holding time for said fluctuation being accepted as a new coupling is between <NUM> milliseconds and <NUM> milliseconds, preferably <NUM> milliseconds.

For the previous purposes, the control unit may comprise one or more internal timers from where obtaining time intervals.

In another preferred example, the capacitive sensors and the control unit are located in a housing, which comprises at least one opening through which the electrodes and the potentiometer access to the outside of the housing in an hermetic way. Thanks to this configuration, the detection module can be placed near the plant with no risk of short circuit when the plant is watered. Optionally, the housing is part of a pot, where a plant can be located.

In relation to the electrodes, at least one can be made of or comprise stainless metal, non-stainless metal and/or carbon. Regarding its shape, at least one electrode may include, but is not limited to, a bar-shaped geometry. In this case, the electrode has a length greater than <NUM> centimeters and a diameter greater than <NUM> millimeters.

According to a second aspect, which does not from part of the present invention, it is provided an interface system for communicating control signals to one or more electronic devices, comprising:.

This interface system is characterized in that one or more electrodes of each detection module is in electrical communication with each plant. Thanks to this configuration, it is provided a reliable system for accurately interpret the interactions of a subject with living plants.

In a preferred example of said interface system, the living plants comprise roots buried in a moist substrate and at least one electrode is in direct contact with the moist substrate. It has been discovered that it is not necessary direct contact of the electrodes with plants for detecting a change in its capacitance -the electrodes being in electrical communication with the plant through a moist substrate is enough.

In another preferred example, the interface system includes a hub, as well as more than one detection module in electrical or wireless communication with the hub. The hub is configured to receive said control signals from the detection modules and redirect them to corresponding external devices. Optionally, the hub may comprise a power port for powering the detection modules, which can be also a communication port. It may further comprise a power port for being powered, which can be also a communication port to an external device -such as a PC. Thanks to this hub, all the detection modules and plants can be interconnected and provide joint control actions.

In a preferred example of the present interface system, at least one plant is of the crass kind. It has been discovered that the coupling interactions with crass kind plants are more feasible to measure, especially when measuring its capacitance.

According to the present invention, it is provided an interface system for communicating control signals to one or more electronic devices, comprising:.

This interface system is characterized in that said living plants are of the crass kind. Thanks to this configuration, it is provided an interface system highly accurate when interpreting if a subject is interacting with it. It is advantageous measuring capacitance changes in a crass plant, but it is also possible detect coupling interactions of a user by means of any other electric attribute of the crass plant. This is due to the high water content of crass plants.

It is afforded a method for providing a user's interaction with a living plant, said method not forming part of the present invention, comprising:.

The present method is characterized in that further comprises adjusting said threshold value through a user-accessible potentiometer in electrical communication with the control unit before sending said control signal for the first time. For example, the potentiometer's adjustment can be performed according to the natural capacitance established by the plant in its location. Thanks to this configuration, the detection module can be calibrated in an easy way when installed and permits feasibly detecting a capacitance change when a subject becomes electrically coupled to the plant -e.g., by touching it. Once the detection module has been calibrated using the potentiometer, the control unit may adjust any drift in the measured signal.

In a preferred example of the present method, it further comprises calculating average voltage values from said voltage values during a given time interval by applying a moving average algorithm, being said average voltage values the ones to be compared with the threshold value.

In another preferred example, it further comprises measuring a dwell time for which the voltage values rate above the threshold value and, if said dwell time is lower than a predetermined dwell duration, avoiding sending the corresponding control signal. Optionally, it may further comprise, after been measured a dwell time higher than a predetermined dwell duration and been detected that the voltage values dropped below the threshold value, measuring a holding time for which the voltage values rate below the threshold value and, if said holding time is lower than a predetermined holding duration, avoid sending a new corresponding control signal.

So that the manner in which the above recited aspects are attained and can be understood in detail, a more particular description of a preferred embodiment of the invention may be had by reference to the appended figures.

It is to be noted, however, that the appended figures illustrate only embodiments of this invention.

A preferred embodiment of the present interface system is illustrated schematically as a block diagram in <FIG>. The present embodiment comprises two detection modules (<NUM>) and a hub (<NUM>) for communicating control signals to an electronic device (<NUM>). Each detection module (<NUM>) comprises:.

In the present embodiment, a first detection module (<NUM>) is connected via its outlet communication port (<NUM>") to the inlet communication port (<NUM>') of a second detection module (<NUM>). Said second detection module (<NUM>) is connected via its outlet communication port (<NUM>") to the hub (<NUM>), the external device (<NUM>).

The capacitive sensor (<NUM>) and the control unit (<NUM>) of each detection module (<NUM>) are located in a housing (<NUM>), whereas the electrode (<NUM>) and the potentiometer (<NUM>) are arranged outside the housing (<NUM>) at the end of a shielded wire. The housing (<NUM>) comprises openings (<NUM>) through which the shielded wires pass through the housing (<NUM>) in an hermetic way. Although in this preferred embodiment the links (<NUM>) between communication ports (<NUM>', <NUM>") have been represented by shielded cables, the links can also consist of wireless links.

<FIG> illustrates a block diagram of an embodiment of installation procedure of the present interface system. In a first step, it is necessary to electrically connect the electrodes (<NUM>) of a detection module (<NUM>) with a plant (<NUM>). Said electrical connection preferably consist on direct contact of the electrodes (<NUM>) with the substrate where the roots of the plants are buried. The substrate should have a moisture content for a better performance. As depicted from the following claims, the present interface system offers the possibility of adjusting the threshold value thanks to a user-accessible potentiometer (<NUM>). In this installation procedure, after initiating the system, the capacitive sensors (<NUM>) measure the capacitance detected through the corresponding plant (<NUM>) by means of the electrodes (<NUM>) and convert said capacitance into voltage values. The control unit (<NUM>) steadily reads said voltage values and compares them with a threshold value while adjusting the threshold value. When the user considers said voltage values being near but under the threshold value, the installation procedure can be considered completed. <FIG> illustrates a block diagram of a first embodiment of the present method for communicating control signals to one or more electronic devices. After initiating the system, the capacitive sensors (<NUM>) measure the capacitance detected through the corresponding plant (<NUM>) by means of the electrodes (<NUM>) and convert said capacitance into voltage values. The control unit (<NUM>) steadily reads said voltage values and compares them with the threshold value. When the control unit (<NUM>) detects a voltage value exceeding the threshold value, a so called dwell time starts being measured, which indicates the duration for which the voltage values rate above the threshold value. The control unit (<NUM>) interprets that there has been a coupling between the subject and the plant (<NUM>) only when said measured dwell time is longer than a predetermined minimum dwell duration. Only then, the control unit (<NUM>) sends the corresponding control signal to an external device (<NUM>) via said communication ports (<NUM>', <NUM>") and hub (<NUM>). This minimum dwell duration is preferably set to <NUM> milliseconds. When the measured dwell time is less than said minimum dwell duration, the control unit (<NUM>) is configured to discard the supposed coupling as a false positive.

<FIG> illustrates a block diagram of a second embodiment of the present method. Compared to the previous first embodiment, after interpreting that there has been a coupling between the subject and the plant (<NUM>), this second embodiment further comprises start measuring a so called holding time when a voltage value drops under the threshold value. The holding time indicates the duration for which the voltage values rate under the threshold value. The control unit (<NUM>) interprets that said coupling has been interrupted by the subject on purpose only when said measured holding time is longer than a predetermined holding duration. Only then, the control unit (<NUM>) gets ready for interpret a new coupling. This holding duration is preferably set to <NUM> milliseconds. When the measured holding time is less than said minimum holding duration, the control unit (<NUM>) is configured to interpret that said coupling has not been interrupted.

Claim 1:
Interface system (<NUM>) for communicating control signals to one or more electronic devices, comprising:
- one or more plants (<NUM>), wherein an electric attribute of any of them is changed when a subject becomes electrically coupled to it, and
- one or more detection modules (<NUM>), each detection module (<NUM>) comprising one or more sensors in electrical communication with at least one of said plants (<NUM>) and configured to measure said electric attribute of the plants (<NUM>) and convert it to voltage values, and a control unit (<NUM>) in electrical communication with said sensors and configured to read the voltage values and send a determined control signal to one or more electronic devices on the basis of the read voltage values,
characterized in that said plants (<NUM>) are crass kind living plants.