The DASH7 Alliance, a non-profit industry consortium that promotes wireless sensor networking standards, today announced the public release of the DASH7 Alliance Protocol.
DASH7, an open source wireless sensor networking standard, competes with Zigbee(900MHz/2.4GHz), Z-Wave (900 MHz), Bluetooth (2.4GHz), WiFi (2.4/5 GHz), and Low Power UWB for machine to machine communications, but features multi-kilometer range, excellent penetration of walls, floors, and water, operates on extremely low power and features multi-year battery life with a maximum bitrate of 200kbps.
Operating in the license-free 433.92 MHz spectrum, DASH7 offers multi-kilometer range, multi-year battery life, sensor and security support, as well as tag-to-tag communications, achieved through ad hoc-synchronized communications. The new protocol is built on the IEC 18000-7 standard and provides seamless interoperability.
“A distinct capability of the protocol provides for both infrastructure to endpoints (RFID tags) and endpoint-to-endpoint communications, while operating from a battery and maintaining low power operation”, said Michael Andre, chairman of the Dash7 Alliance.
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Small solar cells attached directly to a silicon chip can potentially serve as an efficient and reliable power source for wireless sensor networks (WSN). This new technology developed by researchers from the Fraunhofer Institute for Microelectronic Circuits and Systems would greatly simplify large-scale WSN applications, for instance in agriculture.
Almost wherever you go, a team player is more in demand than a lone wolf—after all, those who pull together get the better results. This isn’t just true for people though: sensors, too, are more powerful when part of a team. Sensor networks made up of individual sensor modules that communicate wirelessly with one another have the capacity to measure local parameters over large areas, and then to pass these data on among sensor modules to a central station. This makes sensor networks suitable for a wide range of applications, whether for fire prevention or monitoring large areas of farmland. The issue of how to power the individual sensor modules remains a sticking point in these sorts of applications.
Wiring the sensors together is hardly a viable option nowadays due to the cumbersome and costly installation. What’s more, many applications require the sensor network to blend unobtrusively into the surroundings and not to have an impact on the aesthetics. An example of this would be the systems used for adjusting window positions as part of smart building management programs. Using batteries to power the sensor network does eliminate the need for inconvenient cables, but the amount of maintenance involved in replacing the batteries regularly as required should not be underestimated, particularly in large networks.
Now, researchers from the Fraunhofer Institute for Microelectronic Circuits and Systems IMS have developed an ingenious alternative based on SOLCHIP Ltd IP. The resource they have harnessed to provide power is one that is freely available in almost any location: sunlight. “We use special process steps to place a mini solar cell straight on sensor modules’ silicon chips,” explains Dr. Andreas Goehlich, who heads up the project for Fraunhofer IMS.
This might sound easy at first, but it actually isn’t. For one thing, the Application Specific Integrated Circuits (ASICs) on the silicon chip cannot be disturbed in any way by later steps in the process. ASICs could be termed the brain of the sensor module, facilitating its specific functions. They are manufactured on a piece of silicon in the course of several processing steps, including ion implantation, oxidization or metal deposition. “The structures of ASICs are extremely sensitive, which makes subsequent processing extremely tricky,” explains Goehlich. “That’s why we use a specially developed ‘soft’ processing technology that has already proved itself on a variety of different ASICs.”
More info here.
Thirteen years ago Adam Dunkels was trying to hook up a hockey team in Lulea, Sweden with sensors and cameras so coaches and fans could track helmet cams and players’ vital signs. It was an academic project but it was also an early example of the internet of things. The project was doomed to fail for a variety of reasons, but out of that experience came a lightweight code for connecting devices called Lightweight IP.
A later version of that code became the base for LEGO Mindstorms and a variety of other connected projects. But Dunkels realized that to truly build a platform for connected devices he needed even lighter weight code. So he built Contiki, an operating system of sorts of the internet of things. And now he’s commercializing all that he’s learned in a startup called ThingSquare. In the podcast we discuss the history of the internet of things and when we reached the tipping point that made the internet of things inevitable.
Listen to the podcast here.
Researchers are developing a wireless sensor network (WSN) designed to spot faults in electricity sub-stations that can lead to power cuts. The EPSRC-funded team will develop a WSN capable of sensing partial discharge (PD) in electricity sub-stations, a situation that occurs when the insulation of cables and other power equipment becomes old or damaged. Left unchecked, partial discharge can lead to dangerous and destructive faults including explosions and power cuts. Designed to be monitored centrally, the new WSN will allow operators to replace planned maintenance with condition-based maintenance.
Ian Glover, the new Professor of Radio Science and Wireless Systems Engineering at Huddersfield University told The Engineer via email that the traditional approach to PD detection using free-standing radio receivers has been to measure the difference in time-of-flight from the PD source to a set of spatially separated receivers.
‘The difference in the times-of-flight are found by cross-correlating the noise-like time waveforms arriving at the different receivers with each other,’ he said. ‘The difference in the times-of-flight for a pair of receivers defines a locus of points on which the source of PD could lie. Multiple loci, resulting from multiple pairs of receivers, intersect which gives the location of the source.’ The 4.5 year project, which has received £670,000 in funding, aims to develop a system that relies principally on measurement of PD signal amplitude and does not rely on time measurements. One challenge, said Prof Glover, will be to make the sensors sensitive enough to detect PD at a useful range without requiring sophisticated signal processing, such as the cross-correlation used in the time-of-flight approach. He said, ‘Such signal processing is power hungry and these sensors will probably need to be powered using energy harvesting technologies – solar cells, vibration, stray electric and magnetic fields, for example – if they are not to require expensive maintenance.’
Another challenge, he said, is that the attenuation [loss] of the PD signal in propagating from source to receiver may vary significantly, even for paths of the same length due to the complex propagation environment of the substation.
‘This means that the location of the PD source is almost certainly not possible by simply inverting a path loss law since the path loss law will be unknown,’ said Prof Glover. ‘It may be that we have to ‘calibrate’ our sensors using an emulated PD signal. This itself will require power and may further challenge the energy harvesting solution to maintenance avoidance.’
More info here.
Back in 1999, a technologist called Kevin Ashton pointed out that almost all the information available on the internet–a mere 50 petabytes at that time–had been captured or created by humans in the form of text, photos, videos etc.
Ashton suggested that this was likely to change in the not too distant future as computers became capable of generating and collecting data by themselves, without human oversight.
The technologies required for this are relatively simple–RFID tags for tracking objects, low-power sensors for gathering data on everything from temperature and air quality to footsteps and motion detection, and finally low power actuators that can switch anything on and off–things like lights, heating and air conditioning systems, video cameras and so on.
Ashton called this system “the Internet of Things” and began a number of companies and initiatives to kickstart it.
Since then progress has been seemingly slow. Consumers have been underwhelmed by the idea of remotely controlling a toaster over the internet and disbelieving of claims that their fridge could reliably order milk before it runs out.
But today, Arkady Zaslavsky and pals at Australia’s national scientific research organisation, CSIRO, reveal how the enabling technologies that Ashton imagined have rapidly matured and that the Internet of Things is finally poised to burst into the mainstream.
More info here.
The ultrasmall sensors of the future will monitor our health parameters, vehicles, machines and processes, buildings and smart constructions, and the environment. They will operate autonomously for long periods on a small battery, and they will communicate wirelessly. A key factor for their success, therefore, is their low power consumption, which will define the range of applications and functionalities for which they can be used.
At the 38th European Solid-State Circuits Conference in September, Imec and Holst Centre (Eindhoven, Netherlands) presented four ultralow-power developments to drive next-generation sensors and sensor networks: a frequency-shift-keying receiver for body-area networks, a flexible successive-approximation-register A/D converter for wireless sensor nodes, fast start-up techniques for duty-cycled impulse radio receivers, and a design approach targeting subthreshold operation.
ULP receiver for body-area network applications
Imec and Holst have developed a power-efficient receiver for ULP BAN (ultralow-power body-area network) applications. Whereas most transceivers exploit OOK (on-off keying) modulation, the new receiver uses FSK (frequency-shift keying) modulation and is hence less sensitive to interference. The complete receiver, fabricated in 40-nm CMOS technology, consumes 382.5 μW. The sensitivity measured at a bit error rate of 10−3 is –81 dBm for a 12.5-kbit/sec bit rate. The bit rate is scalable up to 625 kbits/sec, enabling a trade-off between sensitivity and bit rate. Taking advantage of the short-range nature of BAN applications, a mixer-first architecture is proposed, leading to a good dynamic range.
Flexible SAR ADC for ULP wireless sensor nodes
Wireless sensor nodes for electroencephalography, electrocardiography, and temperature and pressure monitoring require ULP ADCs for both the sensor-readout interface and the wireless-communication front end. Each of these applications, however, has its own requirements for accuracy and bandwidth. Imec and Holst Centre have realized a flexible, power-efficient SAR (successive approximation register) ADC that designers can use for a variety of applications. The device supports resolutions from 7 to 10 bits and sample rates from dc to 2M samples/sec; the flexibility is achieved by implementing a reconfigurable comparator and a reconfigurable DAC. The chip, in a 90-nm process, occupies 0.047 mm2, and achieves power efficiencies of 2.8- to 6.6-fJ/conversion step at 2M samples/sec and with a 0.7V supply.
More info here.
From ComputerWorld UK:
I experienced some of the vitality, sophistication and breadth of activity in open hardware and associated software and comms this week at the firstCambridge Internet of Things Practitioners Night meetup.
That demonstrated how a rapid expansion of IoT enabling infrastructure is welling from the bottom-up, and that it’s just a not-too-long matter of time before high-impact applications start to appear.
Among the things that struck me talking to people at the meetup this week were:
- Bright young people are talking and engaging much more with open hardware
- There’s a mix of people of all ages and experience levels engaged in this area and across sectors
- When up against the limitations of current technologies the brightest are building from scratch. That includes operating software, designing circuits, and inventing middleware to exploit fully and efficiently the new open hardware environment
- Crowd-funding is beginning to kick in as a successful alternative to looking for angel investment or venture capital funding for open hardware innovation
- The cost of robust IoT application enablers is plummeting – with high powered Internet connectable boards and components- the nuts and bolts of IoT – costing a fraction of what the industry has become accustomed to.
- The recession is forcing young technologists to do things in new ways and come up with novel capabilities
More info here.