Tag Archives: sensors

Specifying Fiber Optic Sensors

The industry prefers fiber optic sensors as they work well in tight spots and in applications that have a high degree of electrical noise. Fiber optic sensors are useful in machines, fixtures, and conveyors for sensing part presence as an important component of industrial automation. The industry often requires controlling sequence and error-proofing assembly based on the presence or absence of a part. In many cases, it is simply impossible to know whether a part is where it should be or the holder is empty as expected. Therefore, verification is only possible by using a presence sensor.

Sensors come in many varieties, including magnetic, capacitive, inductive, and photoelectric. Depending on the application, each type of sensor has its own merits and demerits. Among all the sensors available in the market, photoelectric sensors offer the broadest types and technologies, and suitable for the widest range of applications.

The family of photoelectric sensors includes a large variety of light-emission types that includes lasers of class 1 and 2, visible, and infrared. They also include different sensing technologies such as through-beam, reflective, suppression, background, and diffuse. Different housing configurations are also available such as fiber optics and photo eye. We will focus on specifying and applying fiber-optic sensors, as these offer the most advanced capabilities with options for configuration, and are most suitable for use in tight spots that the photo-eye sensor finds too small.

Fiber-optic sensors are also known as fiber photoelectric sensors, and comprise of two parts—the amplifier and the fiber cable. The amplifier is the electronic part and is actually a fiber photoelectric amplifier. The fiber-optic cable includes the optic sensor head and the fiber cable to transmit light to and from the amplifier.

All photoelectric sensors work with a simple technique. A light emitter produces the source signal and a receiver detects the signal. A large variety of technologies is available for sensing and measuring the light transmitted to the receiver. For instance, standard photo-eyes look for the presence or absence of light, whereas background suppression sensors sense the angle of the returning beam. Other type of sensors measure the time taken by the light to return, thereby providing a measure of distance it traveled.

Simple photo-eyes such as those used in reflective and diffuse units house the emitter and receiver in the same optical sensor head, while through-beam units house them in two optical sensor heads. On the other hand, fiber-optic sensors have all the electronics in a single housing, with a fiber cable connecting the separate emitter and receiver to the electronic housing. Light from the emitters and that coming to the receivers travels through the fiber cables, similar to high-speed data traveling through fiber-optic networks.

The above segregation means the technician has to mount only the sensor head on the machine, while routing the integrated fiber-optic cable and plugging it into the amplifier placed in a safe place such as a control enclosure to protect it from the harsh manufacturing environment.

A large variety of options is available for both fiber-optic cables and amplifiers. These range from basic to advanced, suitable for meeting the demands of increasing functionality, including advanced logic and communication capabilities.

GrovePi Kits for the Raspberry Pi

If you are looking to interface sensors to the Raspberry Pi (RBPi), the popular single board computer, GrovePi+ from Dexter Industries (SEED Studios) makes it very easy with their starter kit. The kit carries a GrovePi+ board, including more than 10 carefully selected sensors along with the necessary interfacing cables. The kit is very easy to use, as the user only has to plug the GrovePi+ board over your RBPi, and connect the necessary sensor to the board. GrovePi provides a powerful platform for any user to start playing with sensors and hardware.

The simplicity of the GrovePi+ board is evident, as you do not need any other hardware connection—only plug in the board atop the RBPi and initiate communications between the two boards over an I2C interface. The GrovePi+ board acts like a shield and the user can connect any of the Grove sensors from the kit to the universal Grove connector on the board, using the universal 4-pin connector cable available with the kit.

The GrovePi+ board has an ATMEGA328 micro-controller on it, and the Grove sensors, both analog and digital, connect to it directly. The RBPi also communicates with this micro-controller, which performs as an interpreter for the Grove sensors, sending, receiving, and executing commands the RBPi sends it. You can use any RBPi model with the GrovePi+, selecting from among RBPi A+, B, B+2, or B+3

GrovePi+ forms the hardware system for connecting, programming, and controlling sensors that help build your own smart devices. GrovePi+ is small—the size of a credit card—however, it is very powerful. You can think of the GrovePi+ kit as an Internet of Things kit for the RBPi—allowing you to connect numerous sensors to the RBPi—simply by connecting a cable from the GrovePi+ board to the sensor. The manufacturer’s website offers several software examples you can download and try. Alternately, you can write your own programs for the RBPi to control and automate any device.

GrovePi+ does away with the need for connecting sensors to the IoT using breadboards and soldering the sensors. Now it is only necessary to plug in the sensors and start programming directly. Therefore, GrovePi+ is and easy-to-use modular arrangement for hacking your hardware with the help of the RBPi and the Internet of Things.

Using the GrovePi+ system, one can connect over 100 types of sensors to the RBPi. The collection of sensors offered are all inexpensive and plug-n-play modules to sense and control inputs from the physical world. This provides countless possibilities of interacting with sensors, integrating them with the module and the RBPi to obtain unparalleled performance with ease.

For instance, Lime Microsystems and the SEED Studio have a new kit providing everything to start up a Software Defined Radio (SDR) with the RBPi and develop IoT applications for it. The LimeSDR Mini kit targets educational use and is meant for beginners. Lime has optimized the building block for use at 433/868/915 MHz and provides the necessary antennas in the kit. The kit also has an array of sensors from Grove and boards related to output from SEED Studios. The GrovePi+ board offers the computing power for the SDR, and you can use an RBPi 2, 3, or Z.

Using Reed Switches as Sensors

Any ordinary electrical switch has two contacts. Push-type switches are spring loaded so that pushing a button brings them together and they spring apart on releasing the button. Rocker switches have mechanical levers that close the contacts when in one position, while in the other position they pull apart.

In reed switches, the two contacts are in the shape of metal reeds, each coated with a metal that does not wear easily. The reeds are made from a ferromagnetic material, so they are easy to magnetize. The entire assembly is hermetically sealed within a thin glass envelope containing a nonreactive gas such as nitrogen. For extra protection, sometimes the glass envelope may have a plastic casing.

The ferromagnetic material making up the reeds is typically a nickel-iron alloy that shows high magnetic permeability but low magnetic retentivity. That means, when brought close to a magnet, it magnetizes the reeds, which come together in contact. On moving the switch away from the magnetic field, the reeds lose their magnetic property and separate. Their movement has high hysteresis, that is to say they close and open slowly and smoothly. The reeds have a flat area where they contact each other, and this helps to extend the life and reliability of the switch.

Although reed switches typically have two ferromagnetic contacts, some variants may have only one ferromagnetic contact, while the other is non-magnetic. Others may have three contacts, with two non-magnetic and the central one as ferromagnetic.

Like ordinary switches, reed switches also come as two major variants—normally open type and normally closed type. This refers to the position of the reeds when there is no magnetic influence on them. Therefore, the normally open type has its reeds separated from each other, and they close when a magnet is brought close enough. The normally closed type of reed switch has its reeds in contact with each other, and they move apart when a magnet is brought close enough.

As the magnet comes close to a normally open reed switch, the two contacts become magnetized as opposite magnetic poles, and they attract each other to close. In this position, the switch can pass an electric current. This magnetizing of the reeds is independent of the pole of the magnet coming close to them. As the magnet moves away, the reeds lose their magnetism, and their stiff and springy nature makes them spring apart in their original position.

Reed switches are very useful as sensors such as for sensing level of liquids. A sealed stem holds the reed switches at different heights. A float containing a permanent magnet rides on the stem, going up and down as the liquid level changes. When the float magnet comes close to one of the reed switches, it snaps close, changing its electrical status that any electronic circuit can sense. Automotive, marine, and industrial applications use reed switches for level sensing.

A float switch in a dishwasher controls the level of water in the machine. The shaft containing the reed switch is positioned at the water fill limit of the pan. As the water rises, so does a float containing the magnet. When the magnet comes close to the reed switch, it closes, and signals the ECU.

A Rain Alert for the Raspberry Pi

This Raspberry Pi (RBPi) rain alert will let you know when it starts to rain, so you can reel in the clothes you had let out to dry after washing. Although the kit uses an RBPi3, any model of the RBPi family can easily handle this project. A later extension can make it send tweets as well, but for now, it simply triggers a buzzer.

The primary sensor in this project senses falling raindrops. This raindrop sensor is actually a printed circuit board with two traces running across the entire board in an inter-meshed dual comb pattern. As the two sets of teeth of the comb traces remain separated by about a millimeter, they show high resistance when dry. Their resistance decreases when a drop of water falls across the traces, shorting them.

A sensor controller tracks the resistance between the traces, the resistance reducing as more drops of water fall on the sensor. A potentiometer on the controller allows the user to adjust the level of detection when the normally high digital out pin will go low. When the sensor detects rain, it changes the status of the pin. The RBPi, monitoring the status, sets off the buzzer.

Since it is essential to detect the start of rainfall, setting the potentiometer to trigger when a couple of raindrops have fallen on the sensor is adequate. Adjusting it is easy, which you can do when you have two or three raindrops collected on the sensor. Turn the potentiometer until the buzzer just stops, and turn back until you hear it going again.

Since it has to detect raindrops, placing the sensor such that it is always under an open sky is important. However, as electronics and rain do not work satisfactorily together, it is very important the rest of the circuitry remains protected from rain. The best way to achieve this is to have the RBPi and rest of the electronics inside a waterproof plastic case, with only the raindrop sensor hanging out. Run the Python program here and wait for the beeps to inform you everything is working properly.

Apart from the raindrop sensor and its control board, you need only a few other parts to get the kit working. A few jumper wires, an active piezo buzzer, and a mini breadboard are all you need. You can start by connecting the output of the control board to the GPIO18 port of the RBPi to read its status, and set off the buzzer from the RBPi’s GPIO13 port, while the sensor detects raindrops.

If you do not like sounding a buzzer, you can activate some LEDs instead when it rains. Else, program the RBPi to send an email, an sms, a push notification, or tweets a photo warning when it detects rain. Since the continuous sounding of the buzzer will become tiring after a while, you can tweak the code to stop it after a while.

Since the sensor is out in the open, you will have to run out and wipe it dry as soon as it stops raining, to prepare it for detecting the next shower.

Motion Tracking through the MC3672

This year, the MSEC or MEMS & Sensors Executive Congress had mCube exhibiting their incredibly small and low-power MC3672, an inertial sensor product. This is a three-axis accelerometer, and its size is only 1.1 x 1.3 mm. This tiny WLCSP packaged device is a low parasitic unit, with enormous possibilities of unobtrusive use as low power motion tracking in wearable design, and in a completely new set of applications in future.

Recently, mCube acquired Xsens and they were able to couple a sensor fusion software to their tiny accelerometer. This gave them the ability to sense body motion and capture solutions for health, entertainment, and fitness. The combination also allows them to control and stabilize inertial measurement units in industrial applications.

Almost all are aware of MEMS motion sensors, as tablets, smartphones, and wearables use them popularly. Use of the MC3672 accelerometer will generate more applications for these devices in the future. This could include new areas such as in the medical world, related to prevention and diagnostics of illness. For instance, when visually inspecting the throat, stomach, or intestines of a patient, physicians often need to perform invasive and unpleasant procedures.

In future, patients would be able to swallow a camera-pill that can wirelessly beam images from the inside of the body to a display for the physician to view. Miniature motion sensing incorporated within the camera-pill could allow medical practitioners to navigate the pill effectively by actuating and controlling it. This would allow them to monitor its location and orientation in real-time as it passed through the body. Images captured by the camera would enable precise diagnosis and investigation of any problems.

According to Dr. Sanjay Bhandari, Senior VP of mCube, a plethora of new applications will come into life based on the granular, precise measurement of motion, orientation, tilt, and heading of the sensor. For instance, some applications will be able to capture motion data to communicate it to cloud software services, and ultimately sharing it with networked systems for monitoring and analysis.

Achieving most of the envisaged applications is only possible with motion-sensing systems that are extremely small and drain very little power from an arrangement of energy harvesting or a battery.

Along with the low power consumption and small system size, all components in the system must adhere to the design features. The sensor interface uses Silicon and CMOS-based circuits that filter, amplify, and fit the analog to digital processors to work its magic.

The monolithic, single-chip design by mCube integrates both the CMOS and the MEMS within a clever extension using a standard CMOS-base process. This is a reliable procedure for handling high volumes and produces excellent yields. Within the chip, mCube has interconnected the MEMS and the CMOS very efficiently.

In future, mCube plans to integrate BLE or Bluetooth Low Energy into the MCU in its SIP package—they want to realize IoMT-on-a-Chip. They have protected their technology by 100 approved patents.

The acquisition of Xsens brought to mCube the 3D technology to track motion in the sensor world—a high-precision module for sensing motion in 9 degrees of freedom.

Using Hall-Effect Type Sensors Effectively

We are familiar with appliances such as wine coolers, freezers, and refrigerators. They keep out beverages and food cold, extending their useful life. Most often, these appliances have lights that illuminate the insides when the user opens their doors. Since the lights only need to be on when the user opens the door, usually, the designer of such appliances place a sensor to detect the opening and closing of the door.

A sensor of the Hall-effect type can detect the position of the door. In refrigerators, the position of the sensor is within the frame, while a permanent magnet is placed on the door directly opposite the Hall-effect type sensor. For refrigerators with multiple doors, each door needs a magnet and for the detection, each magnet must have a corresponding sensor placed in the frame. The adjustment of proximity of each Hall-effect type sensor and magnet pair is such that the Hall-effect type sensor detects the magnet only as the door closes completely.

An electronic control unit inside the electronics assembly of the refrigerator monitors the output from the Hall-effect type sensors and turns the lights on or off as necessary. Hall-effect type sensors can detect a variety of proximity- and position-sensing applications such as when there is a need to discover the proximity of a moving part relative to a sensor placed in a fixed location.

For instance, Hall-effect type sensors can help to stop the motor opening or closing a garage door once the door has reached its desired position. Typically, this needs a system of two Hall-effect type sensors to detect the two dominant positions of the door—open or closed. Each sensor also needs a corresponding magnet to trigger it.

The position of one of the magnets on the drive chain of the garage door opener places it directly next to the sensor that detects a closed door. The position of the other magnet, also on the drive chain, is such that the drive chain brings it next to the other Hall-effect type sensor as the door opens completely.

Hall-effect type sensors are preferable to other sensors such as reed relays, as the former has no moving electrical contacts, resulting in long life and improved reliability. Other applications that use Hall-effect type sensors effectively are vending machines, security locks on doors, vacuum cleaners, washing machines, dishwashers, and similar applications requiring door- and lid-position sensing.

A flow switch is another application that benefits from the use of a Hall-effect type sensor, which detects the motion of a piston, paddle wheel, or a valve fitted with a permanent magnet. For instance, this arrangement suits tankless water heater units, where the flow sensor has a permanent magnet fixed to a piston. The increasing presence of water pressure in the system moves the piston and its associated magnet near to a permanently positioned Hall-effect type sensor. This causes the output of the Hall-effect type sensor to change and it signals the presence of flowing water.

Similarly, a turbine can have a magnet attached to its blades. As the blades rotate, the magnet passes by a fixed Hall-effect type sensor. The speed at which the blades rotate is proportional to the fluid flowing through the turbine.

Sensing Movement in Three Axes

All modern vehicles must sense the position and movement of automotive control functions such as turn signal indicators and gear selectors. However, engineers face challenges here with conventional sensor technologies as the requirement is for sensing movement in the three axes simultaneously. The challenge lies in the physical size of the device, its reliability, power consumption, and its cost. However, 3-D magnetic sensing technology, recently introduced, could be helping engineers to address these challenges.

It is well known that electro-mechanical switching is a common source of failures in the several applications, including in automobiles. Contacts usually corrode or burn out over a period, causing inconveniences and failure to the owner of the vehicle, also potentially damaging the reputation of the manufacturer of the car. Therefore, most car manufacturers prefer using solid-state technology, such as switching based on Hall-Effect detection of magnetic signals. This method increases the reliability, saves space, and is inexpensive.

When driving a car, among the most common things people do is to signal for a turn and change gears. In the past, most cars used heavy current wiring harnesses around the vehicle for transmitting signals and power. Lately, using a turn indicator or a gearshift is more likely to send a high-impedance signal to a central processing unit rather than physically switching something over.

Vehicular control is becoming more sophisticated and multi-functional, with the trend moving towards sensing in more than one plane. For instance, most modern cars using automatic gearboxes now have sequential controls and move the gear lever into a different plane. That makes the task of sensing position more complex than ever.

Magnetic 3-D Sensing

Hall Effect sensing for implementing 3-D position sensing is actually possible in several ways. One can place individual Hall sensors at the multiple fixed positions where the movement has to be sensed—just as in the case of a turn signal or a gear lever. This may result in as many as seven sensor elements, and the controller will know the position by locating the live sensor.

Another method could be to use flux concentrators. Although this method also uses Hall sensors, the number of sensors used is lower. This is because two pairs of orthogonal sensing elements are integrated into a CMOS IC, whose surface has a deposit of a ferromagnetic film to enhance the magnetic field, increase the sensitivity, and increase the signal-to-noise ratio.

Several algorithms in subtraction and addition make it possible to accurately sense the magnetic field components present in the horizontal (X and Y) and the vertical (Z) directions to the IC. Analog to digital converters then convert these analog voltages from the sensors to digital values and the digital signal processors then compute the final, absolute position.

However, none of the above is a viable solution in the automotive sector, as these are not suitable for mass production, because multiple sensors are involved. However, there is another alternative, also based on Hall-Effect sensors—the TLE493D-A1B6 3-D sensor. This simultaneously determines the x, y, and z coordinates of the magnetic source, while building a 3-D image of the magnetic field that surrounds the sensor.

Sleep Better with a Raspberry Pi

Sleep is an integral part of our lives, and lack of quality sleep quickly leads to a whole host of issues related to physical, emotional, behavioral, etc. Quality sleep is linked to a good environment that includes proper bedding, clothing, temperature, humidity, and lighting among other things. Although electronics may not be able to help much with the proper choice of bedding and clothing, a cheap but versatile single board computer such as the RBPi or Raspberry Pi is a good contender for controlling temperature, humidity and lighting during sleep hours.

When using the RBPi for controlling the environment of the bedroom, it is necessary to build an RBPi-based temperature-monitoring network in the house. This helps to get some hard data on the existing temperature trends at different places, so it will be easy to know whether the solutions tried did actually work. Since temperature is to be monitored at different places at the same time, it is necessary to use remote sensors.

You can use temperature sensors such as the single-wire DS18B20 thermometers for inexpensive and accurate temperature measurement. This model has two types of sensors – transistor-sized and waterproof, and you can use either for the purpose. However, people have found the waterproof sensors were easier to position and calibrate, and they were slightly more accurate as well.

Testing the sensors on the RBPi is simple as this SBC supports the DS18B20 sensors by the built-in w1-gpio library. The RBPi allows easy readouts of the 1-Wire devices. You can wire up a few DS18B20s to multiple RBPI, Model A+ and position them at all main parts of the house. It also helps to integrate data from your Nest Thermostat API, if you are using this and collect the local outdoor temperature data as well – use the Weather Underground, for instance. Monitor the temperatures from the different sensors on a rolling 24-hour graph, and you can make out if there is a trend.

It is possible to even out temperature variations in the house by sealing vents and leakages in areas where the temperature dips. However, this may not be enough to raise the temperature to comfortable levels at locations distant from central heating ducts. Moreover, not all walls of the house may receive equal amounts of sunlight, and this may be another reason for the temperature dropping in certain rooms after sunset.

You can use unobtrusive wall-mounted space heaters to boost the temperature up in these areas. Usually, these are slabs of stone with heating wires running through them. Stone has high thermal capacity, meaning it retains and radiates heat for a long time. This arrangement is also safe for use in children’s bedrooms. When used on a thermostat-triggered outlet, the heater only turns on at a select temperature that you choose. You can fine-tune the settings after monitoring the temperature data for a couple of nights.

This project is useful if you are planning to have an extended network, with remote-controlled HVAC using branch air ducts. Individual controls on the branch ducts can control the airflow, so the system efficiency goes up, such as by turning down the airflow to sections of the house where there is no one present.

How Sensors help Seniors Live Independently

With the benefits of medical science and increased awareness, people are now living longer than their ancestors did. Along with longer living, they also desire to live as independently as possible in their senior years. However, certain risks are part of independent lifestyles. These include inadequate care resulting in deteriorating health and debilitating falls. Researchers are addressing these issues by developing smart homes. They are using sensors and other devices and technologies for enhancing the safety of residents while monitoring their health conditions.

In-home sensors permit unobtrusive monitoring of individuals. That offers enormous potential for providing timely interventions and for improving the health trajectory, because health problems can be detected early, before they become more serious. Therefore, individuals are assured of continued high functional ability, independence with better health outcomes.

University of Missouri has an ongoing project in HAS or Health Alert Systems using sensor technology. They are testing HAS in senior housing in Cedar Falls, Iowa and in Columbia, Mo. They presently use motion sensors to monitor activity, acoustic and vision sensors for fall detection, Kinetic depth images for gait analysis and webcams for silhouette images. They have a new hydraulic bed sensor to capture quantitative restlessness, respiration and pulse. HAS also uses pattern recognition algorithms for detecting pattern changes in the data collected by sensors. Based on this, HAS can generate health alerts and forward them to clinicians, who diagnose them further to determine appropriate intervention.

Researchers at the university are evaluating the usability and effectiveness of HAS for managing chronic heath conditions. They are presently testing the HAS at remote sites, away from healthcare providers. Researchers expect this approach will provide important information on ways to scale up the system into other settings. According to the researchers, the next big step will be to move the system into independent housing where most seniors prefer to be. This will also offer significant potential healthcare cost savings, enabling seniors to live independently.

This research will improve the health care and the quality of life for older adults. Researchers are focusing on newer approaches for assisting health care providers in identifying potential health problems early. This will offer a model in eldercare technology, which will keep seniors independent while at the same time, reducing healthcare expenses. The project also has a plan – It will train the next generation of researchers in handling real, cyber-physical systems. It will mentor students through an interdisciplinary team, while the research outcomes are integrated into the classroom teachings.

Similar efforts are also under research in other places. For example, researchers at the Intel Labs, Carnegie Mellon University in Pittsburgh, are working on ways of taking out the drudgery involved in housework. They are presently designing HERB or Home Exploring Robotic Butler, a smart and resourceful robot. According to the researchers, HERB will be able to walk into a room, assess its layout and move about by itself.

Researchers at Intel Labs believe disabled and senior citizens will adopt robot butlers early on, as they most need help around the house.

How Smart Sensor Technology helps Beehives

Plants are necessary for life on the planet Earth, as they transform the gas Carbon-Di-Oxide that animals exhale into life-sustaining Oxygen. Plants, in turn, depend largely on bees to pollinate their flowers and propagate thereby. That makes honey bees a keystone species, which humans have recognized throughout history. Bees help to pollinate nearly 70% of all plants on earth assuring about 30% of the global food supply. That makes bees a predictor of our planet’s future health.

Global warning has brought with it an alarming rise in the growth rates of damaging pathogens such as fungi, viruses and mites. At the same time, there has been a serious disrupt in the natural rhythms that the bee population had adapted over centuries of consistent seasonal weather patterns. Crop production is infested with pesticides, which bees ingest and transmit back to their hives during pollination. This often leads to a total collapse of colonies. Electromagnetic radiation level in the atmosphere is rising with the exponential growth of cell phones and wireless communication towers. This interferes with the ability of the bees to navigate in flight.

All the above has made it imperative for scientists to monitor the activity of honey bees within their hives in the daytime as well as at night including during inclement weather. At the University College of Cork in Ireland, a group of food business, embedded systems engineering and biology students have recently taken up the challenge. They have developed a unique platform for monitoring, collecting and analyzing activity of bees within the colonies unobtrusively.

The project Smart Beehive has earned top honors in the Smarter Planet Challenge 2014 of IEEE/IBM. Using mobile technology, the project deploys big data, wireless sensor networks and cloud computing for recording and uploading encrypted data.

Waspmote is a modular hardware sensor platform. Libelium has developed Waspmote for any sensor network and wireless technology to connect to any cloud platform. The UCC team of students has used Waspmote as their starting point along with integrated hive condition and gas sensors. They have used ZigBee radios, GSM and 3G communications to study the impact of oxygen, carbon dioxide, humidity, temperature, airborne dust levels and chemical pollutants on the honey bees. The students captured data from initial observations in two scientific papers and three invention disclosures.

According to the famous physicist Albert Einstein, man can survive only for four years on earth if there were no bees left. Smart technology can integrate beehive sensors and analyze the data they collect. Therefore, such platforms play a critical role not only in ensuring continuation of pollination, but also in ultimately monitoring, understanding and managing the precious global resources as well.

The Plug & Sense! Technology from the Libelium Waspmote wireless sensor platform offers the use of a wide range of sensors, integrating more than 70 of them at a time. It can adapt to any scenario of monitoring with wireless sensors such as water quality, vineyard monitoring, livestock tracking, irrigation control, air and noise pollution, etc.

Outdoor deployment is possible because of the waterproof enclosures used by Plug & Sense! Moreover, using solar panels, the honeybee project has the ability to harvest energy.