Interface your OWN sensors to eKo!

Crossbow's new eKo system has not only brought wireless sensor networks into the heart of precision agriculture, the system now also offers a quick and easy solution for anyone wanting to incorporate wireless sensor networks into their own outdoor monitoring solution. Whether they are looking to use eKo for environmental monitoring and research, urban monitoring, pollution detection, etc., this system is on its way to being the wireless sensor networking solution for any outdoor sensing requirement regardless of sensor type. eKo is fully packaged for the elements, solar-powered and ready to use out-of-the-box. This platform now provides users with a solution that requires little effort for complete customization with the new ESB developer's kit. The first phase of this kit has now been released to all eKo users.

eKo nodes (EN2100) can interface to many different types of sensors. Each of the node’s four sensor ports has a 6-pin connector that programmably interfaces to either analog or digital sensors, and each port has the ability to support two different sensors. Crossbow has created a standard interface (ESB: Environmental Sensor Bus) to communicate with a wide variety of sensors through these ports. 

Phase 1 of Crossbow's ESB developer’s kit allows users to interface their own simple analog sensors that do not require any additional signal or power conditioning to the eKo node. Users will only need to program the self-identification EEPROM and wire the sensors to the connector. The EEPROM embedded in the sensor’s connector is read by the port during power-up, and this information tells the node how to communicate with the sensor and contains parameters such as the required operating voltage and power-up time. After the information is read, the node programmably changes the pins according to the ESB requirements.  To request details on using Phase 1 of the ESB Developer's kit with your eKo system, visit Crossbow's site here.

Phase 2 of this kit release will support simple analog sensors requiring additional signal conditioning and/or power conditioning. These sensors use the external interface circuit between the eKo node and the sensor. The self-identification EEPROM is embedded in the Switchcraft connector.

Phase 3 will provide support for complex digital sensors that require signal conditioning, power boost or intelligent communication. These sensors use an external interface circuit between the eKo node and the sensor. They do not require that the EEPROM is embedded in the cable as the self-identification information is contained in the microprocessor. 

As an example of interfacing a simple sensor to eKo, Crossbow has recently integrated the MaxBotix MaxSonar range finder along with an air temperature sensor on the same connector.  The MaxSonar is an accurate, very low cost, ultra-sonic range finder that can run directly from the eKo battery supply at very low current. Also, of interest is to measure the ambient air temperature at the same time. Both of these sensors can be wired to a single eKo port connector.

The entire assembly can easily be mounted in PVC pipe fixtures for outdoor deployment. Once the two sensors are wired a Dallas DS2431 1Wire EEPROM is mounted into the sensor Switchcraft connector. Finally the EEPROM is programmed with the self-identification information. This is done using a programming board and PC program from Dallas Semiconductor. A mating Switchcraft connector is wired to the board to allow the sensor cable to be attached directly and the EEPROM then programmed.

The simplicity of integrating unique sensors with eKo, a fully packaged ready-to-use outdoor wireless monitoring device, enables users to deploy wireless sensor networks quickly, easily and effectively in a way they never have before. To request details on Phase 1 of the ESB Developer's kit, visit Crossbow's site here.

San Francisco Chronicle Features Crossbow's eKo System

Crossbow's eKo system has triggered an agricultural revolution in the world of precision agriculture and environmental monitoring. This cutting edge system was recently featured in the San Francisco Chronicle and the story can be viewed here.

(08-31) 15:50 PDT -- On a rolling hillside planted with row upon row of Cabernet grapes, viticulturist Jason Cole waxes eloquent about the elusive notion of 'terroir,' a term French farmers use to describe the 'je ne sais quoi' of crops harvested in any given locale.

"Grapes, chocolates, coffee, these are all incredibly good at soaking up their environments and spitting them out in their fruits," said Cole, who oversees the preening and pampering of more than 500 acres of vines planted at the Stagecoach Vineyard in Napa County.

That vineyard is a test bed for a new wireless sensing technology that measures soil wetness, wind speed, temperature and humidity to take the statistical pulse of the vineyard's microclimates to help determine how often and how much to irrigate. The system being tested at Stagecoach was developed by Crossbow Technology, a privately held, 90-person San Jose company that has created inertial guidance sensors for the aviation industry and researched the use of wireless sensor networks for the federal Defense Advanced Research Projects Agency. Other manufacturers of microclimate sensing systems include the Austrian company Adcon Telemetry, as well as Ranch Systems of Novato and Grape Networks of San Ramon.

The sensors that Cole is using at Stagecoach Vineyard represent one manifestation of a broader phenomenon called precision agriculture - the attempt to tailor the cultivation of large stretches of land so that the smallest possible subsection of a farm gets special but automated attention. In the Midwest, with its amber waves of grain, precision agriculture has been synonymous with huge tractors equipped with global positioning systems to keep the rows straight, for instance. But in California, the land of fruits, nuts and other specialty crops, precision agriculture has been expressed in technologies such as Cole's efforts to use wireless sensors to compute 'terroir.'

"The way that growers for many years decided whether it was time to water was they stuck their thumb in the ground," said Robert Robinson, vice president for Crossbow's wireless sensor division.

The basic field kit that Crossbow released earlier this year, priced at $3,359, consists of three sensing nodes that feed data collected in the field through an electronic gateway into what is essentially a Web page that can be viewed from any Internet-connected device. Crossbow says that basic configuration can divine the microclimate of sites as varied as a 4-acre plot of land in hilly and varied terrains such as Napa and 20 acres in the flatter, homogeneous Central Valley. Additional kits can extend the sensing network, wirelessly and indefinitely, over hill and dale.

Moisture sensors
Kneeling alongside a vine at Stagecoach Vineyard, Cole explained how the system, in addition to measuring temperature and humidity with above-ground sensors, sticks a virtual thumb deep into the soil in the form of two moisture sensors, one at a depth of 1 foot and the other at 3 feet.



"The whole point is to monitor what the roots are experiencing," Cole said. "Watering grapes is one of the most important factors to wine quality. You want to stress the vines in order to condense the flavor into smaller berries."

UC Davis Professor Stu Pettygrove, a soil specialist who has tracked precision agriculture in California, said the water-sensitivity of wine grapes, coupled with their high value relative to other agriculture products, make them a good candidate for this high-tech approach. But how many other California crops fit that description? Pistachios were the only other example Pettygrove offered. He said water-stinginess at just the right point helps burst the shells, making pistachios easy to eat.

Tree crops experiment
Professor Michael Delwiche, chairman of biological and cultural engineering at UC Davis, has experimented with wireless sensing systems that precisely apply water - sometimes mixed with chemical fertilizers in a process called fertigation - to tree crops like nectarines. So far, however, the cost benefit is not there in production orchards, he said.

Delwiche said wireless sensing systems and precision watering might find a home in commercial nurseries and flower-growing greenhouses, where the impetus is not purely economic - as measured by greater crop value - so much as it is regulatory. "They are under environmental regulation not to have runoff from the nursery location," Delwiche said. Eventually, manufacturers will try to improve the performance and bring down costs to encourage broader adoption of wireless sensing systems, he said. Meanwhile, the technology remains economical in niche markets - or exceptionally arid locales.

"In Israel, where water is so dear and they have the technological infrastructure, they're doing a lot of work in this area," Delwiche said. But at Stagecoach Vineyard, where cachet is central to the business plan, the cost of wireless sensing technology is hardly a barrier to the pursuit of quality.

"We're trying to grasp the 'terroir', but you'll always be grasping, you'll never have it all," Cole said.

For more information on the eKo system, visit the eKo site here.

An ēKo-nomic solution for Nursery Monitoring

If you took a look at the plants in my yard, or had caught a glimpse of the few potted plants I attempted to care for in college it would be quite obvious that my thumbs are not green. The soil would usually be too wet or too dry and the leaves wilted leading to my plant's eventual demise. Imagine having acres and acres of plants to monitor and care for...is there a way to do this ēKo-nomically?

The FLOW-AID project is working to contribute to the sustainability of irrigated agriculture by developing, testing in relevant conditions, and fine-tuning through feedback, an irrigation management system that can be used at farm level in situations where there is limited water supply and water quality. The FLOW-AID project in collaboration with the University of Pisa has installed an ēKo system at an experimental nursery in Tuscany, Italy to monitor soil moisture at eight different locations in the nursery.

The system is designed to serve as an assistant for communication with higher level water management systems at basin scale for long and short term water use planning and prediction. This project integrates innovative sensor technologies into a decision support system for irrigation management while taking into consideration several factors in a number of third country partners. The ēKo nodes have been deployed in eight locations over the nursery in Tuscany. The ēKo ES1101 soil moisture sensors are monitoring the ornamental shrubs and trees being grown to make sure that all the water is being used efficiently and effectively.

The project results yielded will showcase the development and testing of new and innovative, but simple and affordable, technical concepts for irrigation under deficit conditions used at the farm level in a large variety of set-ups and constraints. It will show the development of a water management support system (DSS) that contains an expert system (off-line/long-term) to assist in farm zoning and crop plan in view of expected water availability (amount and quality) with a link to Basin Management, as well as a crop response module that can be incorporated into the irrigation scheduler that allocates available water(s) among several plots and schedules irrigation for each one with a link to Basin Management.

The FLOW-AID project has set up four test sites in various market conditions with different irrigation structures, crop types, local water supplies and constraints. The hardware/software systems used must adapt the general concept of water management to the local situation by using appropriate parts of it at the global sites in Lebanon, Jordan, Turkey and Italy.

The information being collected at the site in Tuscany, Italy, by the researchers at the University of Pisa for container crops and nursery grown crops is available to users over the internet via ēKo's EG2100 gateway device and the ēKoView interface. This device provides, in a fully integrated package the connection between ēKo Sensor Nodes deployed and the ēKo Gateway. The work done by FLOW-AID will be carried out between 2006 and 2009 as a 6th Framework European project under the call for water in agriculture, new systems and technologies for irrigation and drainage. For more information on the ēKo system, click here.

Wireless Soil Moisture Tension Measurements for Irrigation Management

Irrigation is defined as the artificial application of water to the soil usually for assisting in growing crops. In crop production it is mainly used in dry areas and in periods of rainfall shortfalls, but also to protect plants against frost. Irrigation management in agriculture and landscaping is of growing importance as the growing global population puts more demand on finite fresh water supplies. Managing irrigation optimally improves yields and quality while reducing water user and pumping energy costs. Optimal irrigation management requires reliable knowledge of plant water stress and soil moisture status. Many different devices and techniques have been used to gather this type of information, but perhaps none as successful as one of Crossbow's beta ēKo deployments in California's Napa Valley wine country.

Mark Holler is the owner of Camalie Vineyards in Napa, Califorina. He is a viticulturist and a technology enthusiast who has been working closely with Crossbow in the development and testing of the ēKo platform over the past two years to increase the quality and quantity of his grape harvest by using and controlling his water resources. With the data he collected from the ēko platform, Mark has been able to minimize his water use and maximize his yield despite the low water season we saw this past year in 2007. This achievement was not only due to the ēko system's ability to collect data, but Mark's ability to analyze the data and apply it to his growing techniques. Mark has written a white paper on High Density, Multiple Depth, Wireless Soil Moisture Tension Measurements for Irrigation Management. Below is an extract regarding his application and findings. To read the entire article click here:

When sampled sufficiently at appropriate depths soil moisture tensions were found to correlate well with pressure chamber measurements of midday leaf water potential in Cabernet Sauvignon grape wines. Sampling 2-3 sites per acre across a 4.4 acre hillside vineyard produced a substantial correlation of midday leaf water potentials to soil moisture tensions at 24" depth. The correlations were performed on soil moisture data and pressure chamber data from the 2007 irrigation season on the Mount Veeder hillside vineyard on the western slopes of Napa Valley. The data suggests that  soil moisture tension measurements may be able to replace many leaf water potential measurements which are significantly more labor intensive. A strategy for use of soil moisture tension measurements in manging regulated deficit irrigation of grape vines and the monitoring of other irrigation system parameters using the ēko Pro Series is described in this overview.

Correlations were done between leaf water potentials and soil moisture tensions acquired at 12" depth and 24" depth. Data from all locations and times were combined for these correlations. Sample size was 43 points per depth.The soil moisture data at 12” depth does not correlate with the leaf water potential measurements but, at 24” depth there is a “substantial” correlation.  This data suggests that deeper placements of the soil moisture sensors might produce better correlations with the leaf water potentials. 

From the data gathered one could also conclude that the vines were getting their water from deeper depths and that the vines have not concentrated their root growth around the sub surface dripper which is co-located with the soil moisture sensor at 12” depth. This information was useful in deciding not to move the subsurface drippers further from the vines or deeper to encourage root growth.This type of correlation could be used to optimize locations for soil moisture sensing. In an initial deployment many sensors could be placed at different depths at a few locations for the first season. At the end of the season correlations with leaf water potentials could be done and the root zone locations with best correlations determined. The following season more sites would be added with fewer soil moisture sensors per site only at the optimal location(s) in the root zone determined. 

The general success of the 2007 growing season at this vineyard in terms of yield, ripeness and reduced water use supports the use of the modified regulated deficit irrigation though indirectly because there are many confounding factors which affect yield. In 2006 data from the soil moisture sensors was used to optimize irrigation durations and intervals. Soil moisture sensors provide good insight into how water moves within the soil – hydraulic transport, something that leaf water potentials cannot provide. The delay between wetting at 12” depth and 24” depth is a measure of how long it takes water to move downward within the soil. From this the vertical hydraulic conductivity can be inferred. The slope of the drying transient indicates how fast water is moving away from the sensors either due to diffusion or plant uptake. 

Irrigation durations and intervals were optimized to achieve desired average soil moisture at 24” depth. This soil moisture target was based on leaf water potentials as described above. Total available water supply for the season was also considered. We adopted the premise that the vines benefit from reduced variability in soil moisture over time. The best uniformity over time would be achieved by very short durations at frequent intervals. Short durations and frequent intervals, however, do not allow the water to penetrate very far between irrigations. Short intervals also result in non-uniformities across each block because the line pressures are below spec for constant drip rate during start and stop transients. The total start up and shut down transient time for this irrigation system was determined to be about 30 minutes. We set the minimum irrigation duration to 2 hours to make the transient effects less than 25% of the irrigation duration. We then checked to see that the water was reaching the 24” deep sensors consistently with an interval equal to the time it took the 24” depth to dry out to the level before the last irrigation. The interval was then varied to bring the average soil moisture level at 24” depth to the target value. We then looked at the water consumption rate of our optimized duration/interval times and forecasted total use for the season.

If this use was in excess of our water resource we lengthened the interval to the consumption rate we could afford. We then monitored the new average soil moisture and spot checked leaf water potentials to determine if we could keep the vines from becoming over stressed. If the leaf water potentials continue to drop to –15 bar and beyond as was the case in the 2007 season we purchased additional water and trucked it to the vineyard. In 2007 in light of a very dry winter rainfall we delayed irrigation until a higher stress level was achieved to reduce canopy growth and subsequent water consumption by the vines. Our yield and fruit maturity results suggest that this was a good approach. We feel strongly that high water stress transients during the growing season can damage the vines not only in the short term but over several seasons as well.

Camalie used a prototype network during the 2005 and 2006 growing seasons to guide irrigation decisions in the 4.4 acres of Camalie Vineyards. Yield per vine in 2005 was double that of the 2004 yields for same age vines yet the water consumption was kept constant.  Typically water consumption goes up with canopy size which more than doubled for these 2.5 year old vines in 2005. The grape quality was excellent. Of course, some of this success was due to generally better than average weather in 2005 but, Mark and others at Camalie believe their visibility of the soil moisture played a significant role.  Extra drippers were added to some areas of the vineyard based on the soil moisture data.   Also irrigation intervals were shortened based on sensor data to reduce the amount of water that penetrated below the root zones where it would be wasted. In 2006, the third year for their vines, the yields again doubled from 4 tons to 8 tons. In the 4th year, 2007, the network was upgraded to the latest Crossbow technology, the yield again doubled to 16 tons of fruit that was sold and another 1.5 tons that the vineyard made into wine themselves. The yield was 3.97 tons per acre which is very rare on Mt. Veeder especially with water limited due to less than half the normal rainfall in the winter of 2006/07.  Water had to be purchased but thanks to their precision irrigation the vineyard minimized water purchasing and still had great yields.  Fruit quality was excellent as before.

For more insight into the methodology used at Camalie Vineyards, be sure to read the complete white paper here.

 

ēKo series wireless crop monitoring system unveiled

On Tuesday of this week, Crossbow announced the release of ēKo™ Pro Series, a turnkey live data, wireless crop monitoring system enabling precision agriculture. The ēKo Pro Series follows Crossbow’s already popular sensor and navigation solutions for heavy agricultural equipment. See the video below for additional details.

ēKo™ represents the next generation in crop monitoring and precision agriculture techniques, employing a mesh network of wireless sensors and providing vital live data about crop health, vigor and growth progress via a simple internet browser. Among others, the ēKo Pro Series monitoring solution features the following innovations:
• Solar-powered, field-deployed wireless sensor nodes, which require no electrical power so that sensors can be placed where needed.
• Simple-to-use, web-based data viewing that allows remote access to live sensor data, critical trend charts and alarm settings - all of which are highly customizable.
• Leading-edge, reliable wireless mesh network technology that is self-configuring and self-healing, thus providing effortless setup and easy scalability, where additional wireless nodes and sensors can be added easily by non-technical users.

ēKo Pro Series drives increased profits and competitive advantage by enabling lower input costs, mitigating crop loss risks, increasing per-acre yields, and delivering higher quality crops with greater consistency.

“ēKo Pro Series enables growers to consistently improve yield and quality regardless of the variability in the terrain, soil or micro-climates,” said Robert Robinson, VP of Sales and Marketing at Crossbow. “Growers can now overcome the traditional trade off between higher yields vs. higher quality and can achieve a higher average price on larger harvests consistently by executing precision agriculture techniques with ēKo Pro Series data."

ēKo eliminates concerns about reliability and complexity in applying wireless technology to deficit irrigation and precision agriculture by delivering a more integrated solution including all the sensors, software application, sensor nodes, and network components that growers need to quickly and easily deploy a wireless monitoring system.

“ēKo takes crop monitoring using wireless technology to whole new levels in terms of reliability,  flexibility, and ease,” said Alan Broad, Director of Environmental Products at Crossbow. “Its mesh based architecture with capabilities such as data re-routing, self-organizing/self-healing network, autodetection of new nodes delivers proven reliability, effortless deployment, and easy scalability. Moreover, the unique sensor interface provides the flexibility to add any sensor from third-party vendors in the future."

The ēKo Pro Series Starter Kit provides a quick, easy way to get started with wireless monitoring. It includes an ēKo Pro Series Network Gateway, 3 ēKo Pro Series wireless nodes, 6 soil moisture/ temperature sensors, 1 ambient temperature sensor, and built-in web-based monitoring application. Additional wireless nodes and sensors are simple to add. The new ēKo Pro Series will begin shipping in volume in April 2008. Pricing and advanced sales inquiries may be directed to sales@xbow.com. Crossbow previewed the ēKo Pro Series at the Unified Wine & Grape Symposium in Sacramento, California on January 29-31 this week. To learn more about the use of ēKo for wireless crop monitoring, visit www.xbow.com/eKo.