Testbed Testing

Wireless sensor network testbeds are critical for understanding and meeting the technical challenges of networks deployed in real world scenarios. Hardware and software testbeds have become the preferred basis for experimenting with embedded wireless sensor network applications. They provide a means for developing and evaluating sensor network technology in a controlled and instrumented environment. Experimentation with current hardware and software platforms, allows users to not only demonstrate applicability in real environments but also to validate prototypes. Compared to field deployments, the testbeds yield substantial efficiency in instrumenting potentially long-lived experiments, which is valuable in the debugging, validation, and integration phases of reliable wireless sensor networks. Universities and labs across the world have set up networks of hundreds of nodes using a Mote platform from Crossbow's suite of wireless sensor network devices choosing from simple platforms such as the TelosB to advanced devices like the Imote2.

Researchers at the University of Buffalo, SUNY and Georgia Institute of Technology have written an article focused on the the idea of taking wireless testbeds to the next level by incorporating multimedia and characterizing the challenges of wireless multimedia sensor networks (WMSNs). The availability of low-cost hardware has enabled the development of WMSNs, i.e., networks of resource-constrained wireless devices that can retrieve multimedia content such as video and audio streams, still images, and scalar sensor data from the environment, along with standard wireless sensor networks. Research is being conducted on prototypes of multimedia sensors and their integration into testbeds for experimental evaluation of algorithms and protocols for WMSNs. Open research issues and future research directions, both at the device level and at the testbed level, are discussed and tested constantly.  Network testbeds allow the effectiveness of algorithms and protocols to be evaluated by providing a controlled environment for measuring network performance.

Every testbed utilizes a specific Mote platform that is optimized for that particular testbed's focus. The wireless sensor platform is chosen based on its available capabilities to allow for multimedia integration. A WMSN is a distributed wireless system that interacts with the physical environment by observing it through multiple media. Furthermore, it can perform online processing of the retrieved information and react to it by combining technologies from diverse disciplines such as wireless communications and networking, signal processing, computer vision, control, and robotics. Applications in the real world that would benefit from WMSNs were categorized into the categories of surveillance, traffic monitoring and enforcement, personal and health care, gaming, and several elements of environmental and industrial monitoring by researchers at SUNY, Buffalo and Georgia Tech. Testbeds allow the observation of the performance of the WMSN in a controlled environment. Hence, the effect of different types of inputs, physical operating conditions, and subjects for sensing can be studied, and the functioning of the devices in the testbed may be changed appropriately for accurate measurement. A few WMSNs developed are outlined below:

A visual sensor testbed was developed as part of the Meerkats project to measure the tradeoff between power efficiency and performance. Results revealed that there was significant energy consumption in keeping the camera active, and writing the image to a Flash memory followed by switching the camera off conserved energy. There was also a finite instantaneous increase in the energy consumption due to state transients. Researchers were also able to determine that the processing-intensive benchmark resulted in the highest current requirement, and transmission was shown to be only about 5% more energy-consuming than reception.

Expandable, vision-, and sensor-equipped wireless robots with MICA sensor motes for networking were designed in the Explorebots testbed architecture. The target localization experiments on the testbed, composed of these mobile robots, used on board multimedia sensors such as custom-designed velocity and distance sensors, motor movement control, an in-built magnetic two-axis compass, and sonic sensors. By processing the sound and light sensors outputs, the robots were guided towards the target source.

The Mobile Emulab network testbed provided a remotely accessible mobile wireless and sensor testbed. Robots carried motes and single-board computers through an indoor field of sensor-equipped motes. A remote user could position the robots, control all the computers and network interfaces, run arbitrary programs, and log data in a database. The path of robots, which was also equipped with Webcams, could be planned, and a vision-based system provided positioning information with an accuracy within 1 cm.

IrisNet (Internet-scale resource-intensive sensor network services) was an example software platform for a heterogeneous WMSN testbed. Video sensors and scalar sensors were spread throughout the environment and collected potentially useful data. IrisNet allowed users to perform Internet-like queries to video and scalar sensors that spread throughout the environment. The architecture of IrisNet was two-tiered: heterogeneous sensors implemented a common shared interface and were called sensing agents (SAs), while the data produced by sensors was stored in a distributed database that was implemented on organizing agents (OAs). Different sensing services were run simultaneously on the architecture. For example, a set of video sensors could provide a parking-space finder service, as well as a surveillance service.

In the design and implementation of SensEye, a multiple-tier network of heterogeneous wireless nodes and cameras, was created to test surveillance applications. Each tier comprised nodes equipped with similar cameras and processing ability, with increasing resolution and performance at each stage. The lowest tier consisted of low end devices, i.e., MICA2 Motes equipped with 900 MHz radios interfaced with scalar sensors, e.g., vibration sensors. The second tier was made up of motes equipped with low-fidelity Cyclops or CMUcam camera sensors. The third tier consisted of Stargate nodes equipped with Webcams that could capture higher fidelity images than tier 2 cameras. Tier 3 nodes also performed gateway functions, as they were endowed with a low-data-rate radio to communicate with motes in tiers 1–2.The aim was to efficiently undertake object detection, recognition and tracking by triggering a higher tie into the active state based on a need basis.

The WMSN-testbed at the Broadband Wireless Networking (BWN) Laboratory at Georgia Tech was based on commercial off-the-shelf advanced devices and had been built to demonstrate the efficiency of algorithms and protocols for multimedia communications through wireless sensor networks. The testbed was integrated with the scalar sensor network testbed, which was composed of a heterogeneous collection of Imote and MICAz motes from Crossbow. The testbed allowed the integration of heterogeneous devices in experimental testbeds and some succesful examples in developing APIs and system software for WMSNs.

These are just a few of the various wireless sensor network testbeds found worldwide. Crossbow's vast portfolio of wireless sensor platforms provides researchers and government/commercial users with the equipment they need to set up a lab for their wireless sensor course or to verify their specifications prior to real world deployment of their wireless sensor network. For information on how to set up your own WSN testbed or for details on Crossbow's wireless sensor network platforms, contact sales@xbow.com.

GOOOOOOAAAALLLLL!!!!

Soccer (or as it is more widely known - football) has often been considered the most popular sport in the world. Wherever you go, there are kids on the street or in a park kicking around a ball, jerseys from the most popular football clubs can be seen in every major city, and the truest World Cup truly does include most of the nations on this earth. It seems fitting that Motes would enter the arena of sports through soccer. The idea behind Motes and wireless sensor networks is to create a device that will become ubiquitous throughout this planet enabling us to live in a smarter more connected world. Soccer has connected people from all over, at all ages with all levels of skill for generations, and now Motes have made their way into this arena with a little bit of fun!

Embedded systems are increasingly becoming connected through wireless networking.  These devices now form the basis of many of today’s consumer products including cell phones and video game controllers.  In the CSE466 “Software for Embedded Systems” class in the Department of Computer Science & Engineering at the University of Washington, students used the design of a multi-player video game as motivation for the  principal concepts in wireless embedded systems.  Each student in the class designed an accelerometer-based game controller and then, the class as a whole, developed a multi-player video game that allowed 28 players (the number of students in the course) to play simultaneously. How did they do it? With Motes!

Computer Engineering curricula have traditionally included the interfacing of sensing and actuation devices to microcontrollers but have not emphasized wireless communication. This time students at University of Washington undertook the task of updating the platform used in this course to Crossbow's Imote2 which runs an embedded Linux operating system and developing a multi-player video game using controllers modeled on the, then just introduced, Nintendo Wii video game controller. Previous courses had used the MICA Mote platform, but the Imote2 offered a device with greater capabilities.

Each student designed their own Wii-like accelerometer-based 2-D game controller.  An LCD screen was added so that game state could be displayed on the user’s controller during the game. The Imote2 platform offers users an expansion connector for attaching sensing and actuation hardware.  On one side, students attached the basic ITS400 Imote2 sensor board which includes a 3-axis accelerometer, temperature sensors, a humidity  sensor, a light sensor, and a 4-channel A/D for further additions.  On the other side, students designed their own board to provide some actuation known as the "SuperBird".  A cell phone-size color LCD screen as well as sound generation capabilities, a speaker, microphone, and audio jacks.  This board also included a cell phone camera, jog dial, USB host port, barometer, and a heart rate sensor and is the form factor of a large cell phone. While not all of the board’s capabilities were used in this particular application, the board was designed to be flexible enough to accommodate a variety of projects (such as a video phone, music player, etc.) in the future. The Imote2 platform is based on Linux and students were provided with the device drivers for their project implementation.

 

Students decided on utilizing controllers that could move a player in two dimensions.  Soccer quickly emerged as a game that could be varied to accommodate the project requirements, namely, that it should involve every student simultaneously and require only two-dimensional control of each player.  In addition, students wanted to have some collaborative elements between players that would spur real team play - soccer being a true team sport! The game was developed in steps.  Development began with the basic player controller, that is, the mapping of values from the accelerometer to an X-Y velocity vector.  A communication protocol needed to be devised on top of the basic MAC of the 802.15.4 radio to handle the communication between players and  the game coordinator.  To ensure that there was some inter-player communication, the “captain” of the merged players (the player with
the highest number) collected all the moves of the constituent players and reported that result to the game coordinator.  The scheme was basically round-robin.  The game coordinator polled the first player for its move and waited for a response before proceeding to the next player.  If a player was too slow in responding, its movement was ignored for that round.  This provided some timing constraints on the implementations to quickly handle packets from the game coordinator.  The boards were programmed to allow students to control players in the virtual soccer-like game. Tilting the board would cause the player (represented by a dot on the field) to go in the corresponding direction.

On the final day of the course a 30-minute soccer match was held between the two sections of the class.  A video of the match and an explanation of the project can be seen here:

GOOOOOAAAAAAAALLLLLL for CSE466 at University of Washington!!

Robocopters and Motes

Crossbow's Motes were featured last month in an article on IEEE Spectrum. The application featured showcases how the Motes can be used when deploying mobile distributed communications networks.

The meter-long helicopters lined up under the fluorescent lab lights at the Berlin Technical University might look like overgrown toys, but they’ve got a little more under the hood. These are flying robots. They take off, land, and scout terrain autonomously and are being wired to deploy ad hoc communications sensor networks. And unlike any other robocopters, they can work together.

Researchers expect they’ll be used to distribute sensors that would help coordinate firefighting efforts or search flood zones, to track or find people and vehicles, or to shoot movies and cover sports events. Hoisting communications gear, they could one day help channel radio, Wi-Fi, or mobile phone traffic where infrastructure has been wiped out by an earthquake or other natural disaster.

Several groups around the world are working on miniaturized robot helicopters with advanced intelligence, notably in California, South Carolina, the Netherlands, South Korea, and the UK. But the Berlin team believes it is the first to write software and build systems that get multiple robot copters to collaborate. The project brings together a half-dozen institutions and companies from across Europe.

The copters’ control systems allow small craft to work together in lifting loads and scouting environments. Coordinated, the copters can lift weights that would normally require larger, exponentially more expensive machines. Estonian robotics engineer Konstantin Kondak, a professor at TU Berlin and one of the project’s leaders, says that having three or four copters in the air, each sharing the load while tethered by a rope to a single object, creates too many contrary forces for a set of human pilots to handle: “If you try to do this flying manually, it is not a stable system. You have to correct at all times; it’s too much.” But autonomous robots, making instant and coordinated adjustments, can do the job, he says.

Each robot must account for the location of the other helicopters, the forces coming from them, and the load on the rope, to jointly lift something. The helicopters’ coordination comes from a system that integrates four software modules for stabilizing the copter: one for navigation, one for exploration, one for obstacle avoidance, and one for processing orientation, horizon, and position.

The robocopters are good for much more than just lugging things around. Project manager Aníbal Ollero, a professor of engineering and automated systems at the University of Seville, in Spain, says that a flexible, easy-to-transport team of choppers makes for more efficient scouting because they automatically divide an area among themselves.

They’re also faster at another important task: deploying distributed communications networks by dropping off sets of tiny sensor nodes. These nodes combine a data processor, a radio, a battery, and—depending on what needs measuring—temperature, light, radiation, location, or chemical sensors. For the autocopter project, off-the-shelf nodes from wireless-sensor firms Crossbow Technology and Ambient Systems were optimized and linked by data-routing experts at universities in Stuttgart, Germany, and Twente, Netherlands. Just a few centimeters across and 7 millimeters thick, the individual nodes transmit over a range of just 25 meters, but as a network they pass radio messages to one another to get to a central unit (or hovering robocopter). Hundreds of thousands of these nodes could be distributed by robot to survey a forest fire or flood zone for rescue efforts, according to the researchers.

Final trials for the project get under way, far from the Berlin winter—this spring in southern Spain, Ollero says. If all goes well, helicopters will deploy a sensor network, track mobile objects and people, follow movement inside and outside of buildings, and capture it all with high-end airborne cameras.

For more information on Crossbow's Mote platforms, visit www.xbow.com.

Sensors Help Keep the Elderly Safe, and at Home

The New York Times published a front page story regarding how sensor technology is changing the face of home health care. The article discussed how increasingly, many older people who live alone are not truly alone. They are being watched by a flurry of new technologies designed to enable them to live independently and avoid expensive trips to the emergency room or nursing homes.

Crossbow's wireless sensor network technology has been used in a plethora of various research and project deployments on the capabilities of integrating wireless sensor network technology for elder care. Recently, researchers at Kalasalingam University in Nadu, India published their project details in the Jan/Feb Issue of Telemedicine and eHealth on using the IRIS and Imote2 platforms for home health monitoring. The issue they address is real as the increasing demand on public health care due to the aging population has become a major problem in developed countries. With the increasing number of elders relying on home care, better monitoring and analysis systems are crucial for maintaining and improving the quality of life for the elder patients. The concept of health monitoring is advanced by which health parameters are automatically monitored at home without disturbing daily activities. The proposed system is a network that supports various wearable sensors and contains on-board general computing capabilities for individual event detection, alerts, and communications with various medical informatics services. The purpose of their system is to provide extended monitoring for elderly patients under drug therapy after infarction, data collection in some particular cases, and remote consultation for elderly people.

With the advancement in ubiquitous computing techniques, researchers at Kalasalingam University proposed this new system for health monitoring at home to assess the elderly peoples’ health status. The integration of sensing, information, and communication technologies allowed elderly people to be constantly monitored. Moreover, constant monitoring would increase early detection of adverse conditions and diseases in elderly patients, potentially saving more lives. The proposed healthcare system was built upon a global medical information system made up of three main components: (1) Various sensors of different types to monitor physiological signals of elderly patients, their environments, and their activities with sensor nodes kept in the patients’ home; (2) Sensor nodes to transmit the signal from sensors to central servers through a base station; and (3) Central server for management of a knowledge database related to patients and responsible for broadcasting messages and alarms to healthcare professionals and caretakers. The system proposed a technique for monitoring elderly patient status at home and detecting critical situations for the purpose of alerting the doctors as well as the caretakers. It consists of a front end, the patient station, and the server.

The Patient Station, consists of an IRIS (XM2110CA) sensor node, Crossbow's newest 2.4GHz Mote platform for ultra low-power, long-range wireless sensor networking that receives information from the physiological sensors. The 3D camera kept at home was connected with the Imote2 platform (IPR2400CA) to visually monitor the elderly patient in the home environment in addition to the physiological signals. The Imote2 sensor node is aimed at applications involving data-rich computations, where there is a need for both high performance and high bandwidth, which require greater processing capability and low-power operation with a low duty cycle to achieve longer battery life. Sensor nodes are responsible for sensing as well as the first stage of sensory data processing in the data communication. The received signal from the patient station was transmitted to the central server for analysis. Researchers found that the benefits of the IRIS mote included excellent radio frequency range, substantially lower sleep current, and double the program memory of other Mote offerings. By Integrating a high-performance, low-power PXA271 Intel processor and an 802.15.4 radio with a built-in 2.4-GHz antenna, the Imote2 provided a platform for digital imaging applications.

Researchers placed sensor nodes equipped with flex sensors on the chest for ECG, and on the right hand for heart rate and acceleration measurement. The IRIS sensor node placed on the body was responsible for collecting physiological data and movement data from the sensors and transmitting it to the central servers through the aggregation node. The aggregation sensor nodes do not act merely as data collecting and forwarding points. Instead, they make decisions whether the information should be stored for future use, relayed as they are, or modified by applying computation and aggregation with other data.

The server, which is the core processing element, received the patient’s data from the patient station through the base station and stored the data into the patient database, while performing long-term trend analyses and prediction. It dispatches the critical events detected by sensor nodes to healthcare professionals. Moreover, it coordinates and controls the overall functionality of the system. This system can also give the alert to the doctors via a personal digital assistant (PDA) or cell phone. The sensor nodes could be programmed to awaken the node whenever an abnormal signal is detected and transmit the data to the server and then return to sleep mode. When an abnormality was detected in the sensor node, it would automatically turn on and transmit the signal to the central server and simultaneously alert the caretaker near the patient. The server, which is the core processing element, received the data regularly from the sensor nodes for analysis. The analysis was done using Crossbow's MoteView, and operates under TinyOS, which offers a built-in library for data acquisition, processing, analysis, and display.

The central servers were programmed with two algorithms. First was the threshold based algorithm, which attempted to identify the physiological parameter values that were potentially harmful or indicative of immediate danger to the patients. The algorithm detected the upper and lower threshold values from sensors output and alerted medical personnel and caretakers when the patient was not physically capable of requesting help. Second was the inactivity detection algorithm for detecting rapid movement or lack of movement of elder patients from accelerator output. The sensor node was programmed through the central server in such a way that if lack of movement/ action is detected, it awakened the Imote2 device connected to a 3-D camera fixed in that specific room to send the status of the elder patient to a central server. Upon detecting an anomalous event, both algorithms would sound an auditory alarm from the central server to emergency departments and alert the caretakers near the patients.

In this implementation, researchers at Kalasalingam University were able to connect two different systems, that is, the patient record database and the Web portal, through the use of well-defined Web services. Patient information was transmitted over SOAP, a secure and encrypted form of XML. The WSDL (Web Service Definition Language) for these Web services is published to a community of authorized users. This Web-service based approach for inter-system communication gives the system the flexibility to operate with third-party software in the future.The proposed system used a wireless sensor network technology within the residence in order to increase functionality, security, and quality of life.

As the Times put it, 'The future of these technologies, and the terabytes they gather, can involve unprecedented information about the whereabouts and well-being of older people.'

IMB400 Imote2 MultiMedia Board Wins EG3 Editor's Tech Choice Award

Crossbow's IMB400 Imote2 MultiMedia board has been chosen as the recipient of the EG3 Editor's Tech Choice Award for Winter 2009! The platform is now in the running for the Readers Choice Award! The eg3 Tech Choice awards are the newest and one of the largest "reader's choice" awards in the embedded and electronic design industries. The awards commend new products that take promising technologies and provide practical ways that design engineers and programmers can turn these technologies into real designs, today.

To participate and vote for the IMB400 in the Reader's Choice Awards, please visit the eg3 site here and take their survey to vote for your choice in the different product categories. Crossbow's Imote2 Multimedia Board (IMB400), an integrated camera sensor board, is up for the 'Best Wireless Product' Reader's Choice Award. The IMB400 is innovative in the way it simplifies the capture of rich media content for wireless sensor network applications. Building on the popular Imote2 advanced wireless sensor platform, the IMB400 offers a compact, power efficient solution due to its integration of camera, audio and motion detection functionality into one platform. The built-in camera can handle high-quality images with resolutions up to 640x480 pixels and 30 fps, along with audio at sampling rates of up to 48kHz.. For more information on the IMB400 Imote2 Multimedia board and to purchase this platform, visit Crossbow's site here.

eg3.com is the oldest and largest web resource devoted to electronic design, with a focus on embedded systems, real-time computing (RTC), and digital signal processing (DSP). Founded in late 1994, eg3.com indexes free and non-commercial design information on the net, summarizes the over 800 vendor companies that make up this marketplace, and organizes the content of major chip companies and third party vendors into a searchable "design tool" for embedded engineers and designers.

Imote2.Net edition featured on EngineeringTV

The .NET Micro Framework is a platform that enables developers to more quickly develop embedded systems that are smart, securely connected and easier to manage. Jonathan Kagle, Microsoft's .NET Micro Framework Senior Program Manager, introduces some of the hardware developers are using in Micro Framework devices, including Crossbow's Imote2.Net Edition wireless sensor node platform on Engineering TV.

The Imote2.NET Edition (IPR2410) is built around the low-power PXA271 XScale processor and integrates an 802.15.4 radio (CC2420) with a built-in 2.4GHz antenna. The Imote2 IPR2410 is factory configured to run .NET Micro Framework. It is also sold as part of the Imote2.Builder kit.The Imote2.NET Edition is a modular stackable platform and can be expanded with extension boards to customize the system to a specific application. Through the extension board connectors sensor boards can provide specific analog or digital interfaces. A battery board is provided to supply system power, or it can be powered via the integrated USB interface.

Open SESAME!

These magical words won't take you to a cave of treasures, but they do lead us to some exciting applications for wireless sensor networks that open up a treasure trove of information previously inaccessible. SESAME: SEnsing for Sport and Managed Exercise has a vision in which athletes and coaches are continuously provided with precise and relevant information about their performance, their body state and posture, presented in a form determined by sport-specific training requirements based on a careful analysis of coaching methods and coaches’ informational needs. To realize this, athletes wear an easily-extensible range of different sensors that capture accurate information about their position, skeletal posture, muscular response, and physiology in a way that is non-intrusive and capable of working in the context in which the athlete normally performs. This setup is engineered so as not to cause injury, discomfort or performance degradation and it must not interfere with aerodynamics. Wearable sensors are complemented by track-side monitors and video capture equipment and by an integrated hardware/software/network platform designed to enable substantial volumes of data to be gathered, recorded, analyzed and presented to athletes and coaches in the most accessible and useful form. The main objective of the SESAME project is to conduct high-quality scientific research to produce deployable systems that have a positive and measurable impact on the training of elite athletes.

Researchers at the University of Cambridge have just released an open source low power 802.11 sensor board tailored for Crossbow's Imote2 platform. The SESAME consortium is a multidisciplinary group consisting of 6 partners with University of Cambridge Engineering Department as a member. The sensor board developed is designed to support the high data rate requirements of the sports sensing application. The UCAM-WSB100 is a low power wireless sensor daughter board for the Imote2 platform designed to facilitate high data-rate wireless sensor applications. Developed to support the SESAME project, the board will be used to collect real-time and off-line processing and feedback in enhancing the performance of elite athletes. 

Overview of the UCAM-WSB100 sensor board:
* Compatible with the Imote2 processor board
* Low Power 802.11 b/g based on Marvell 88W8686 chipset
* Supports ad-hoc and infrastructure modes
* Access to power control of the radio system
* 12 analog channels (12-bits resolution)
* Physical dimensions: 48mm x 36mm
* Linux driver support via libertas drivers in mainline kernel

 

The information obtained from the sensors will be pre-processed on the athlete to take account of the measurements required and the prevailing network conditions. The data is then transmitted wirelessly to a base-station and application platform. Here, the data will be further fused and processed in a way that is informed by an understanding of biomechanical models of athletes; an understanding of the consequences of sensor placement error and physical properties of the method of attachment; and the coaching objective for which the data are being captured. Within SESAME, the primary experimental focus will be on sprinting, for which precise technique is hugely important and mechanical constraints on performance are well understood. Consequently, the derived data will include the position, velocity, acceleration and orientation of the athlete, their stride length and rate, body posture and instantaneous pressure in the shoes, as well as physiological data such as heart rate and blood oxygen level. The data will then be output in three different ways: they will be sent for long term storage and offline analysis; they will be presented visually to the coaches in a way that is meaningful to them; and they will be returned directly to the athlete in real time as biofeedback.

The UCAM-WSB100 is created as an open source platform. As part of the effort to develop open source hardware for use in conjunction with Crossbow's Imote2, the details of the hardware reference design (schematics, board layout diagrams) are available to the wireless sensor network community. Users will be able to easily tailor the system to their particular application. Researchers at the University of Cambridge are seeking volunteers to help improve the hardware reference design and add support for this board in other operating systems such as TinyOS and .Net. If interested in participating in this development, click here and for more information on this project, click here.

Crossbow Announces IMB400 Imote2 Multimedia Board

Building on its popular Imote2 advanced wireless sensor platform, Crossbow Technology announced the new Imote2 Multimedia Board (IMB400), an integrated camera sensor board that simplifies the capture of rich media content for wireless sensor network applications. The IMB400 board adds rich media capabilities to wireless sensor platforms. 

Ralph Kling, Chief Architect for Crossbow Technology said “For the first time visual and audio data can be easily added to wireless sensor applications. This opens up new possibilities for wireless sensor applications, including for example, surveillance, machine vision, object tracking, animal behavior surveys, and elder care monitoring in locations and environments that would otherwise be too costly to observe with traditional monitoring systems.”

The Imote2 Multimedia Board offers a compact, power efficient solution due to its integration of camera, audio and motion detection functionality into one platform. The built-in camera can handle high-quality images with resolutions up to 640x480 pixels and 30 fps, along with audio at sampling rates of up to 48kHz.
Instead of using compute intensive image analysis to detect motion, the IMB400 uses a Passive InfraRed (PIR) sensor to pick up movement, which then activates the camera allowing for its operation as a low power device. These images can subsequently be stored, locally processed and transmitted with accompanying sound.

In addition to the PIR sensor, key subsystems include a color image and video camera chip along with an audio capture and playback CODEC. The board is supported under TinyOS, with future support planned for Linux, SOS and the Microsoft .NET Micro Framework. For more information and to order this exciting new platform, visit Crossbow's site here.

iFit, UbiFit, Wii all be Fit

In today's world of excitement and constant stimulation it is sad to note that most people are not fit. We are constantly sitting - at work in our cubicles, at home in front of the TV, on the couch playing video games, staring into our computer screens without moving... the busy lives we lead do not allow us to focus on our fitness. This trend has been noticed by organizations, researchers and companies worldwide. It has even taken over the gaming world. As I turned off my Wii system the other night after a rousing session of Guitar Hero, I began to think about Nintendo's new Wii Fit device. The idea of the Wii Fit is to offer "an environment in which working out is less daunting and as a result enjoyable -- fun, even." Imagine having the capabilities of the Wii Fit in a mobile device that can monitor your activity all the time. The idea of fitness and self image is nothing new to society but with the various technologies being employed it is becoming even easier to improve your fitness and be aware of your body's activity. So why don't UbiFit...?

Researchers at University of Washington and Intel Research Seattle have been investigating how ubiquitous computing can help encourage people to sustain an increased level of physical activity that can be determined by developing a device that can be used to monitor a person's physical activity and fitness. This change is only possible by sensing the person's physical activities (i.e. walking, sitting, etc.), modeling this information and supporting real-time awareness and feedback goals with automated journaling and methods to motivate sustained behavior changes. UbiFit is geared to improving fitness through mobile devices. Now instead of calculating the steps you took with your pedometer and logging how many miles you ran, etc., your UbiFit system will collect and store all of that data for you for real-time analysis. This unique mobile sensing platform is built around the Imote2 platform. The Imote2 is an advanced wireless platform designed for data rich wireless sensor networks requring a higher bandwidth than the traditional Mote devices. Its high performance capability and small size made it ideal for this application.

In the UbiFit project, researchers are investigating how ubiquitous computing can help encourage people to sustain an increased level of physical activity. Overweight and obesity, which are linked to several serious health problems, have become a global epidemic, affecting over one billion adults worldwide. While the medical community agrees that physical activity and fitness are essential to addressing this epidemic, many adults have difficulty increasing and then maintaining physical activity in their everyday lives. Enter UbiFit. Embedded activity recognition systems typically have three main components such as 1) a low-level sensing module that continuously gathers relevant information about activities using microphones, accelerometers, light sensors, 2) a feature processing and selection module that processes the raw sensor data into features that help discriminate between activities, and 3) a classification module that uses the features to infer what activity an individual or group of individuals is engaged in and analyze the data against the individuals set goals.

The sensor component of the UbiFit system consists of the 'Mobile Sensing Platform' (MSP). This device has ten built-in sensors such as a 3D accelerometer, 2D compass, barometer, humidity, visible light, infrared light, temperature with UART, GPIO breakouts for additional sensors. The wearable MSP devices have 2GB flash storage and uses the Linux OS. The raw data is collected from the sensors on the MSP and fed to the Imote2. This data is then sent to a cellular or PDA like device. The feature of the UbiFit system that makes it appealing to users is its client interface called UbiFit garden. The UbiFit garden uses the on-body sensing, real-time statistical modeling of the  activity data and its novel personal display to encourage physical activity. This is not limited to detecting a specific pre-planned physical activity such as using the Nintendo Wii Fit or Nike+ system. It is not just a physical activity detection device like a pedometer. The UbiFit garden encompasses all these areas and rolls it into an easy to use and carry personal fitness monitoring device. Set up to be background on a users cellular device, the UbiFit garden background blooms on the user's mobile phone providing key information at-a-glance such as whether they are having an active/inactive week, whether they have met their weekly goal, etc. and encouraging them to incorporate physical activity into everyday life.

For more details on this project visit their site here, and for more details on the Imote2 platform visit Crossbow's site here. Now, get up off of that couch, strap on those walking shoes and UbiFit!

Imote2.Builder Kit featured in InfoWorld

InfoWorld has reviewed and featured Crossbow's Imote2.Builder kit in an article last week. The kit was reviewed by Strategic Developer Martin Heller who stated that, "The Imote2.Builder Kit makes creating wireless sensor networks a snap." From his article:

I spent several hours today exploring the Crossbow Imote2.Builder Kit, a "complete development environment for high performance wireless sensor networking (WSN) applications leveraging the Microsoft .NET Framework," as the company describes it.

(I'd never say "leveraging" and "Microsoft" in the same sentence myself if I could avoid it, because of Microsoft's rather checkered legal history of "leveraging" its near-monopoly -- but oops, I did it again. Back to Crossbow.)

The Imote2 .Builder Kit sells for $990 in the U.S. in small quantities. It includes three Imote2 processor boards, two Imote2 sensor boards, two battery boards, batteries, a USB cable, and software on CD-ROM. Obviously, individual boards are cheaper, especially in quantity.

Why so many boards? The processor boards also have radios, and can talk to each other using the 802.15.4 protocol. The Imote2 has an XScale CPU @ [13–416] MHz and a DSP, 256kB SRAM, 32 MB of SDRAM and 32 MB of FLASH, and baker's dozen of I/O ports of various stripes in addition to the radio and antenna. It has two pairs of connectors for sensor boards, a set for a "basic sensor board" on one side and an "advanced sensor board" on the other side. The flash image includes the .NET Micro Framework.

The sensor boards that come with the kit are of the basic variety, but I guess that refers to the connector they use: they actually have a 3d Accelerometer, an advanced temp/humidity sensor, a light sensor and 4 channel A/D.

The Imote2 software is an add-on to Microsoft Visual Studio 2005 (yes, 2005, not 2008) and .NET Micro Framework 2.0 (yes, 2.0, not 2.5). A 90-day trial version of Visual Studio 2005 Professional is provided with the kit.

I found the programming model for the Imote2 easy to understand, as I was already fluent in C# and familiar with Visual Studio 2005 and the .NET Micro Framework. I think I could build wireless sensor network applications with this kit very quickly: in days to weeks, depending on the complexity of the application.

The processors seem plenty fast. Debugging is trivially easy. The only trouble I had with the kit was a minor but annoying deployment issue: sometimes a board would stop taking downloads, and code deployment from Visual Studio would fail. I was always able to recover from this by stopping all the software on the PC that talked to the board, disconnecting the board from the USB bus, reconnecting and resetting the board, and restarting the software.

According to the company, this is most likely a problem with the Microsoft USBSPOT driver. Once I had a board programmed, it would be fine.

The picture at the top of this article is the hardware configuration for the most advanced demo in the kit, a star network in which two battery-powered CPU/sensor stacks transmit accelerometer data, one CPU board receives the signals and sends them over the USB cable, and the PC plots the live output, as shown at left. Overall, this is a very impressive kit.

Martin Heller is a Web and Windows programming consultant, is a Contributing Editor for InfoWorld. He develops databases, software and sites, and writes, edits and consults from his office in Andover, Massachusetts, as he has for over 20 years. For more information on Crossbow's Imote2.Builder kit, please contact sales or visit our website here.