All posts tagged: energy

The new PSoC-4 BLE series of programmable system-on-chip devices from Cypress enables system designers to create low-power, sensor-based wirelessly-connected systems using integrated programmable analogue front ends, programmable digital peripherals – industry-leading CapSense touch sensor capability for user interfaces all integrated together with a Bluetooth 4.0 (Bluetooth Low Energy) radio and an ARM Cortex-M0 microcontroller in a compact and cost-effective single-chip solution.

This highly-integrated one-chip Bluetooth Low Energy platform enables you to easily design low-power, wirelessly-connected solutions that are particularly well suited to real-time, low-power Internet-of-Things applications.

Bluetooth Low Energy has several potential benefits over Wi-Fi in some wireless connectivity applications, including minimal connection latency and very good energy efficiency, allowing for “always-on” smart, connected devices that run off small batteries for many months or even more than a year while seamlessly being embedded into everyday physical objects and the environment around us.

This makes the platform ideal for IoT end-node applications despite offering data rate and throughput that is lower than in Wi-Fi-based solutions. By combining the Bluetooth Low Energy radio with a 32-bit ARM Cortex-M0 processor in a single chip and adding flexible general-purpose analogue and digital peripherals – the PSoC 4 BLE platform aims to provide the right combination of processing horsepower and low power consumption with flexible and precise interfaces for external peripherals such as ADCs and sensors.

You can interface your Bluetooth-connected system with multiple different sensors easily by integrating custom analogue front ends and programmable digital peripherals around the high-performance 48 MHz ARM Cortex-M0 processor core, with no need for any extra chips.

The PSoC 4 BLE platform includes the Bluetooth Low Energy Protocol Stack and Profiles in an intuitive and easy-to-use GUI-based configuration tool, simplifying the design of your BLE systems. The PSoC 4 BLE chipsets reduce the complexity of RF antenna-matching network design by including an integrated balun, which also helps reduce the component count and the PCB footprint of your system.

A PSoC 4 BLE development kit has been designed by Cypress to allow for maximum flexibility in your design whilst also being as easy to use as possible and offering compatibility with standard Arduino-compatible “shields” when used in conjunction with appropriate software.

This development kit is built around easy to use PSoC 4 BLE and PRoC (Programmable Radio-on-Chip) BLE development modules which are complete, self-contained systems that include the main chip with all its I/O pins exposed for development, a tuned PCB antenna on board, power circuitry and easy access to programming pins.

You can simply hook up some sensors, LEDs and a coin-cell battery and you’re ready to go with your complete single-chip Bluetooth LE-enabled wireless sensor network device with analogue and digital acquisition on board. You can even design reliable, sophisticated and sleek user interfaces with Cypress’ CapSense capacitive touch-sensing technology, delivering superior noise immunity, water tolerance and proximity sensing in touch-sensitive applications such as user control panels.

Furthermore, these modules are FCC certified, so they can be deployed in your commercial products without requiring the certification that you may require for a bespoke RF design to meet FCC Part 15 regulatory requirements. These Cypress PSoC 4 BLE modules also meet CE and Canadian RSS-210 radio certification standards, so they’re ready to go into these markets in your commercial designs.

The Bluetooth Low Energy Pioneer Kit from Cypress enables customers to evaluate and develop BLE projects using the Cypress PSoC 4 BLE and PRoC BLE devices. The low-cost BLE Pioneer Kit includes example projects for common BLE profiles and example smartphone apps for both iOS and Android with full source code provided, allowing you to get up and running in no time with the development of Bluetooth Low Energy solutions for IoT applications.

You can design complete, sensor-based BLE systems easily with Cypress PSoC Creator, taking advantage of its vast catalogue of pre-characterised and production ready PSoC firmware “components” which enable you to concurrently design hardware and firmware with easy drag-and-drop assembly of modular software. For example, the Bluetooth Low Energy 4.1 specification has been abstracted into the new Bluetooth Smart “component” in PSoC Creator.

The Cypress PSoC 4 BLE development kit includes a Bluetooth Low Energy USB dongle that pairs with the CySmart BLE master emulation tool from Cypress, converting your Windows PC into a powerful Bluetooth LE debugging environment.

The kit design and layout allows for customers to easily develop embedded solutions that require both mixed-signal analog and digital capabilities along with wireless Bluetooth LE connectivity and highly optimised power efficiency without sacrificing microcontroller performance.

The development kit supports system-level designs using the Cypress PSoC Creator development environment, which includes numerous example projects to enable you to get started creating Bluetooth Low Energy connected, mixed-signal analogue embedded designs such as wireless sensor networks and IoT product designs as easily and as quickly as possible.

If this platform is of interest to your organisation – and you need an experienced partner to progress with – join us for an obligation-free and confidential discussion about your ideas and how we can help bring them to life – click here to contact us, or telephone 1800 810 124.

LX is an award-winning electronics design company based in Sydney, Australia. LX services include full turnkey design, electronics, hardware, software and firmware design. LX specialises in embedded systems and wireless technologies design.

Published by LX Pty Ltd for itself and the LX Group of companies, including LX Design House, LX Solutions and LX Consulting, LX Innovations.

The new ZigBee Smart Energy 2.0 (SEP2.0) ZigBee Application Profile brings with it powerful new ZigBee capabilities for smart energy metering and control networks. With its ability to transport rate, demand, and load management messages to and from networks of smart energy appliances and the “Smart Grid” across a wide variety of wired and wireless media, the profile promises to be a key element of residential energy management systems.

Capable of passing energy-related messages across a HAN, or Home Area Network, using numerous different types of wired or wireless physical media, SEP2.0 is aimed at enabling the next generation of interactive smart appliances, HVAC, lighting and energy management systems – a “Smart Grid” of energy-efficient technology.

An IP-based HAN enabled by ZigBee Smart Energy 2.0 makes it possible to manage every aspect of the energy consumption and production of a home or building, whilst moving the information around a network built entirely around the Internet Protocol and interconnected with existing networks and the Internet.

The ZigBee Smart Energy 1.0/1.1 Profile was originally developed to allow 802.15.4/ZigBee low-power wireless mesh networks to support communication between smart meters and products that monitor, control and automate the delivery and consumption of electricity – and potentially other household utilities such as gas and water, moving into the future.

The functionality of the Smart Energy 1.x Profile was primarily intended to support the functional requirements of smart meters being used by electricity, gas and water utilities to manage their distribution networks, automate their billing processes, and communicate with customers’ energy management systems.

ZigBee-enabled smart meters act as communications gateways between the utility and the consumer, enabling the exchange of messages about pricing, demand response and peak load management. At least this technical capacity exists in theory, but electricity retailers will only bother with it if they have a revenue model in implementing such technology.

The ZigBee Smart Energy 2.0 Profile was created in response to the need for a single protocol to communicate with the growing universe of energy-aware devices and systems that are becoming common in homes and commercial buildings. For that reason, a diverse range of Function Sets were defined under SEP2.0, including Demand Response and Load Control, Metering, Billing, Pre-Payment, Directed Messaging, Public Messaging, Price Information, Distributed Energy Resource Management and Plug-in Electric Vehicle Management.

One or more of these Function Sets can be used to implement one of the Device Types defined in SEP2.0, such as Meters, Smart Appliances, Load Controllers, Smart Thermostats, In-Premises Displays, Inverters and Plug-in Electric Vehicles to name just a few.

ZigBee Smart Energy 1.x access the MAC/PHY layers of the 802.15.4 radio hardware via the ZigBee Pro protocol stack, but SEP2.0 replaces the ZigBee Pro protocol stack with the ZigBee IP stack, which uses the 6LoWPAN protocol to encapsulate the proprietary ZigBee packet structure within a compressed IPv6 packet. At the transport layer, IP packets bearing messages containing standard ZigBee command and data packets are exchanged using the familiar HTTP and TCP protocols.

When used in combination with the SEP2.0 Application Profile, the ZigBee IP stack provides a media-independent interface between the network and MAC layers of the stack that allows SEP2.0 packets to be carried across nearly any IP-based network.

A recent version of SEP2.0 includes support for communication across ZigBee and 802.11 wireless LANs as well as powerline communication (PLC) networks. SEP2.0 will also have improved future support for 802.15.4g, where the physical layer of the ZigBee/802.15.4 network is a sub-gigahertz radio at, say, 900 MHz for long-range outdoor telemetry or environments where the 2.4 GHz spectrum is congested. Support is also improving for other popular network technologies such as Ethernet.

Amongst the first SEP2.0 enabled products to hit the market will be Energy Service Portals (ESPs) which serve as a bridge between an energy utility’s communication infrastructure and the IP-based Home Area Network. These portals are provided to consumers by utility companies, and use the SEP2.0 Energy Services Interface profile to provide a bridge between the SEP1.x protocol used by most existing smart meters and the home’s IP-based network.

A ZigBee-enabled home energy management system can employ multiple Application Profiles to provide unified control of all home energy systems. For example, a smart home energy management system may use the Smart Energy (SE) profile to pass the utility’s load management and demand response messages to the home’s major loads and energy sources.

The Home Automation (HA) and RF for Consumer Electronics (RF4CE) profiles may then be used to communicate with Smart Appliances, lighting systems and other consumer-controlled products. Energy-aware homes will also employ a large number of end-point applications such as smart thermostats, in-home energy displays (IHDs), and tablet-based control panels that use SEP2.0-enabled ZigBee or Wi-Fi radio links to communicate with the home’s ESI and other elements of its energy management system.

SEP2.0-equipped network endpoints may also be implemented with the physical layer of the network using power line communications, networking smart appliances without RF spectrum congestion.

The ZigBee Alliance has created well-defined provisions for interoperability with, and upgrade paths from, the earlier SEP1.x standard to SEP2.0, which is good news for engineers looking to upgrade or to interoperate with existing SEP1.x technology. There is no significant increase in the processing power required in your hardware, although the key generation and exchange functions in the SEP2.0 security layer may be tough for 8-bit microcontrollers to handle unless they have security acceleration capability, handling the cryptographic maths in dedicated hardware.

Unfortunately, in terms of memory, SEP2.0 and the applications it supports require significant increases in both flash and RAM over what is required for most SEP1.x applications. Storing the code for a SEP1.x stack, a small application profile and a simple user application requires roughly 160 kb of flash in a typical microcontroller, plus 10-12 kb of RAM. Implementing comparable functionality under SEP2.0 requires about 256 kb of flash and 24-32 kb of RAM.

As an example of an existing hardware reference solution targeting SEP2.0, Texas Instruments provides an example consisting of the CC2533 802.15.4 RF system-on-chip, which runs the MAC/PHY layers of the SEP2.0 stack on its built-in 8051 core, combined with one of TI’s ARM7 Stellaris 9000-series microcontrollers as the application processor, running the remainder of the network stack and the application code.

Most of the microcontrollers in this powerful family include a fully-integrated Ethernet MAC, CAN interface, USB host controller, and enough memory and processing power to implement many simple SEP2.0 applications.

It is also worth considering some of the highly integrated single-chip solutions on the market such as the Texas Instruments CC2538, which integrates a 2.4 GHz 802.15.4 radio, ARM Cortex-M3 32-bit microcontroller core, hardware security acceleration for SEP2.0 and plenty of flash and RAM to support the ZigBee IP stack, SEP2.0 profile and application code with support for over-the-air firmware flashing capability for updates in the field, all in a single chip.

As you have just read, the new profile offers a great amount of promise in terms of functionality and convenience for the end user. Here at the LX Group our engineers have an excellent understanding of the Zigbee platform and have put this to use to create various systems for a wide range of customers – and we can do this for you too.

To get started, join us for a confidential discussion about your ideas and how we can help bring them to life – click here to contact us, or telephone 1800 810 124.

Published by LX Pty Ltd for itself and the LX Group of companies, including LX Design House, LX Solutions and LX Consulting, LX Innovations.

The Bluetooth wireless data protocol has been in use for over ten years, and in recent time the new low energy standard has been introduced. This gives designers another option for wireless connectivity between devices with an extremely low power consumption. In the following we examine what it is, the benefits and implementation examples.

Bluetooth LE (for “low energy”) is aimed at novel applications of short-range wireless communication in connected Internet-of-Things devices for medical, fitness, sports, security and home entertainment applications, and was merged into the main Bluetooth specification as part of the Bluetooth Core Specification v4.0 in 2010.

Also known as “Bluetooth Smart”, it enables new applications of Bluetooth networking in small, power-efficient Internet-of-Things devices that can operate for months or even years on tiny coin cell batteries or other small-scale energy sources. Bluetooth LE devices offer ultra-low power consumption, particularly in idle or sleep modes, multi-vendor interoperability and low cost, whilst maintaining radio link range that is sufficiently long enough for the intended applications.

The Bluetooth LE protocol is not backwards-compatible with the “classic” Bluetooth – however, the Bluetooth 4.0 specification does allow for dual-mode Bluetooth implementations – where the device can communicate using both classic Bluetooth and Bluetooth LE. Whilst Bluetooth Low Energy uses a simpler modulation system than classic Bluetooth, it employs the same 2.4 GHz ISM band, allowing dual-mode devices to share a common antenna and RF electronics for both Classic and Bluetooth LE communication.

Small, power-efficient devices like wearable athletic and medical sensors are typically based on a single-mode Bluetooth LE system in order to minimise power consumption, size and cost. In devices like notebooks and smart phones, though, dual-mode Bluetooth is typically implemented, allowing communication with both Bluetooth LE and classic Bluetooth devices. When operated in Bluetooth LE mode, the Bluetooth LE stack is used whilst the RF hardware and antenna is usually the same set of hardware as used for classic Bluetooth operation.

Devices using Bluetooth LE typically have a power consumption, for Bluetooth communication, which is a fraction of that of classic Bluetooth devices. In many cases, devices can operate for a year or more on a single coin cell. This potentially makes Bluetooth LE very attractive for Internet-of-Things networks, telemetry and data logging from environmental sensor networks, for example.

Since many modern consumer devices such as mobile phones and notebooks have built-in Bluetooth LE support, data can be delivered directly to the user’s fingertips from the Bluetooth sensor network with no need for an intermediary gateway or router as would be required for an Internet-of-Things network employing other technologies such as 802.15.4 ZigBee. This direct interoperability with a large installed base of smart phones, tablets and notebooks could potentially be a very significant attraction of Bluetooth LE networks in wireless sensor network and Internet-of-Things applications.

An active Bluetooth radio has a peak current consumption on the order of about 10 milliamps, reduced to about 10 nanoamps (ideally) in sleep mode. In a Bluetooth LE system, the objective is to operate the radio with a very low duty cycle on the order of about 0.1-0.5%, resulting in average current consumption on the order of 10 microamps. At an average current consumption of 20 microamps, such a system could be operated off a typical CR2032 lithium coin cell (with a charge capacity of 230 milliamp-hours) for 1.3 years without battery replacement.

The lower power consumption of Bluetooth LE is not achieved by the nature of the radio transceiver itself (since the same RF hardware is typically used, in dual-mode Bluetooth devices), but by the design of the Bluetooth LE stack to allow low duty cycles for the radio and optimisation for transmission in small bursts – a Bluetooth LE device used for continuous data transfer would not have a lower power consumption than a classic Bluetooth device transmitting the same amount of data.

The Bluetooth specifications define many different profiles for Bluetooth LE devices – specifications for how a device works in particular families of applications. Manufacturers are expected to implement the appropriate profiles for their device in order to ensure compatibility between different devices from different vendors. A particular device may implement more than one profile – for example one device may contain both a heart rate monitor and a temperature sensor. Here is a non-exhaustive list of a few different Bluetooth LE profiles in use:

Health Thermometer Profile, for medical temperature measurement devices.
Glucose Monitor Profile, for medical blood glucose measurement and logging.
Proximity Profile, which allows one device to detect whether another device is within proximity, using RF signal strength to provide a rough range estimate. This is intended for security applications as an “electronic leash”, allowing the detection of devices being moved outside a controlled area.
Running Speed and Cadence profile, for monitoring and logging athletic performance.
Heart Rate Profile, for heart-rate measurement in medical and athletic applications.
Phone Alert Status Profile, which allows a client device to receive notifications (such as an incoming call or email message) from a smart phone. As an example, this is employed in the Pebble smart watch.

The Bluetooth LE shows a lot of promise, and with a minimal chip set cost gives the designer another cost-effective wireless protocol. And if this meets your needs but you’re not sure how to progress with a reliable implementation, we can partner with you to take care of this either in revisions of existing products or as part of new designs. With our experience in retail and commercial products we have the ability to target your product’s design to the required end-user market and all the steps required to make it happen.

We can create or tailor just about anything from a wireless temperature sensor to a complete Internet-enabled system for you – within your required time-frame and your budget. For more information or a confidential discussion about your ideas and how we can help bring them to life – click here to contact us, or telephone 1800 810 124.

The Internet of Things holds great potential, and much has been written about the final applications and the possibilities – however one major factor of any device is how it will be powered. It’s all very well to have the latest sensors or interactive devices, if they don’t have a suitable power supply. It’s easy to consider a battery – however there’s many more options that can increase lifespan, reduce maintenance calls and therefore the running costs. Let’s review a few options that can provide a portable power supply for your IoT nodes where mains power or cabled-in power supplies are not available.

First, consider solar photovoltaic – a common choice for sensing, control or measurement devices that are located outdoors where sunlight is available, and that consume a relatively small amount of power. For a small, low-power embedded device that receives a reasonable amount of sun each day, a moderately small solar panel is perfectly capable of supplying sufficient power – on average – to run a small, basic wireless network node consisting of a microcontroller, some sensors and an embedded low-power Wi-Fi, Bluetooth or 802.15.4/ZigBee radio transceiver. However this is assuming that the overall system is designed for a reasonable degree of power efficiency.

However, solar power is intrinsically intermittent and is only available on average for a fraction of the day. To allow the system to have access to the current it needs to function when needed, solar-powered wireless devices almost always need to incorporate a small amount of energy storage in the form of a battery or supercapacitor in conjunction with the solar cell. Furthermore, solar cells or solar panels typically have a relatively low output voltage if a small number of cells are used, and their non-linear V-I curve makes it desirable to employ Maximum Power Point Tracking (MPPT) where practical.

This is necessary to keep the system operating near the maximum power point so that the limited energy available is harvested most efficiently. A solar power supply for a remote wireless system ideally tracks the maximum power point of the cell along the V-I curve and is able to charge a small battery or supercapacitor to fill in the demand when sufficient sunlight is not available.

As an example of a controller IC one may use for the power supply in a small solar powered system, the Linear Technology LTC3105 is a high efficiency step-up DC/DC converter that can operate from input voltages as low as 225 millivolts, with a built-in maximum power point controller (MPPC). As well as solar cells, this device is well suited to other low voltage, high impedance energy harvesting transducers such as thermoelectric generators and fuel cells.

Whilst it is not a true maximum power point tracker, the user-programmable maximum power point setting helps to optimise the efficiency of energy extraction from any energy source, such as a thermoelectric pile or a solar cell, where the voltage across the transducer may vary with changing environmental conditions as well as with the load current. The LTC3105 is capable of supplying 70 mA of output current at 3.3V from an input voltage of 1 volt – this is sufficient power to run a small, well designed basic sensor node consisting of a microcontroller, RF transceiver and a sensor or two.

Another type of power supply is known as energy harvesting, made possible by parts such as the Linear LTC3108, which is designed to accommodate energy harvesting from transducers with extremely low output voltages, as low as 20 millivolts. This makes it particularly well suited for use with thermopiles and thermoelectric generators which can generate a very low potential difference from a realistic temperature difference – a potentially convenient energy source for remote sensing in industrial automation or process monitoring in high-temperature systems where wired communications and power are not convenient.

Energy can also be derived from vibration, and using a part such as the Linear LTC3588 – a piezoelectric energy harvesting power supply controller which connects to a piezoelectric crystal to harvest mechanical energy in the form of vibrations from the ambient environment. This IC incorporates a low-loss, full-wave bridge rectifier and is capable of accommodating the rapidly changing AC voltage output and high source impedance of a piezoelectric crystal subject to mechanical stress and converting this energy into a DC current with relatively high efficiency.

Output voltage selections between 1.8V and 3.6V are available with a continuous output current capability of up to 100 milliamps, compatible with a range of modern power-efficient microcontrollers and RF mesh systems-on-chip.

An electromechanical energy harvester of this sort can be employed to provide a continuous source of a small amount of “free” energy for a small, efficient wireless network mote, particularly in applications such as vehicles and industrial machinery where plenty of vibrational energy is available to be harvested in the environment.

Finally, for some systems it is also practical to use just batteries – for example, lithium-ion, lithium-polymer or nickel-metal hydride batteries – and rely on user intervention to simply
recharge and replace the batteries where needed. The batteries may be left internally, inside the device, with the system being plugged into a power supply via a charging port
– perhaps using a low-power standard power-supplying interface such as USB – when the device requires a recharge, as opposed to the traditional method of removing and swapping the batteries.

In this sort of application, battery management and charging ICs such as the Microchip MCP73833 Li-polymer / Li-ion charge management controller can be of use to control the recharge of a Li-ion cell, as can buck/boost converters such as the Texas Instruments TPS63031. A buck/boost converter like this allows a regulated output voltage to be generated from input voltages both higher and lower than the desired output voltage – an output of 500mA at 3.3V, in this case, from an input voltage anywhere from 2.4 to 5.5 volts. This allows a battery such as a two-cell NiMH, three-cell NiMH, or single-cell Li-ion / Li-polymer to be used efficiently and charged and discharged across the entire usable part of its discharge curve without hitting the minimum input voltage of a LDO or buck regulator.

No matter what your device or where it will be located, finding an appropriate source of power is possible, and easier than you realise. It just takes a little research and a team of dedicated engineers with the experience and knowledge to understand your requirements. Here at the LX Group we have the experience and team to make things happen. With our experience with connected devices, embedded and wireless hardware/software design, and ability to transfer ideas from the whiteboard to the white box – we can partner with you for your success.

Published by LX Pty Ltd for itself and the LX Group of companies, including LX Design House, LX Solutions and LX Consulting, LX Innovations.

Recently an increasing number of networked devices are finding their way into consumer, industrial and medical applications. Such networks often employ distributed nodes which cannot practically be connected to the power grid – through design or through necessity. Therefore powering such devices can possibly be a challenge – due to the costs of either running from battery or solar power, sending technicians for maintenance visits to replace batteries – or having to install one’s own power network for the IoT system.

This is where energy efficiency is key – by using highly energy-efficient design practices in both the hardware and software levels, the power requirements can usually be reduced significantly. In doing so the power supply paradigm can be altered to one of lower cost and higher efficiency. Especially for remote or portable devices that use RF/microcontroller chipsets – the smaller the power requirement the better.

High-power and efficient wireless network nodes can be engineered using modern RF microcontroller system-on-chip devices, activating sensors and peripheral hardware devices only when they are required, and then putting them into low-power sleep modes when not in use. Similarly, the RF transceiver can be switched into a very-low-power sleep state until the microcontroller decides that a transmission of collected sensor data is required. The microcontroller can then wake up the radio, perform the required transmission, and then revert to sleep mode.

In some cases, a burst of data transmission across the wireless network might only occur when a small, intermittent energy-harvesting power supply has accumulated enough energy in a capacitor to power a transmission. Alternatively, a low-power wireless sensor node can “wake-on-radio”, only taking the microcontroller out of its sleep state when a message is received over the wireless network requesting a sensor readout and only powering up the sensors and microcontroller at this time.

With most of the components of the system, such as the microcontroller, radio and sensors – each kept off-line or asleep for the largest practical amount of time – efficiently designed wireless sensor nodes may achieve operating timescales as long as years off a single battery. Today’s typical wireless RF microcontroller system-on-chips targeted at IoT applications typically consume about 1-5 microwatts in their “sleep” state, increasing to about 0.5-1.0 mW when the microcontroller is active, and up to around 50 mW peak for brief periods of active RF transmission.

However when considering the design of energy-efficient, low-power IoT sensor networks, it can sometimes be advantageous to think not just in terms of power consumption, but in terms of the amount of energy required to perform a particular operation. For example, let’s suppose that waking up a MEMS accelerometer from sleep, performing an acceleration measurement and then going back to sleep consumes, say, 50 micro joules of energy; or that waking up an RF transceiver from sleep, transmitting a burst of 100 bytes of data and then going back to sleep consumes 500 micro joules.

If we know the specific energy consumption of each operation, then the average power consumption is simply the energy per operation multiplied by the frequency of that operation, summed over the different kinds of operations. Of course, this assumes that the continuous power consumption of each device when it is asleep is very small and can be ignored. Alternatively, if we have a certain known power budget available and a known energy budget for each sensing, computation or transmission operation – we then know the maximum practical frequency at which a sensor node can perform sensor measurements and transmit its data.

Additionally, efficient wireless sensor nodes can take advantage of some form of energy harvesting power supply – employing energy sources such as solar cells, vibrational energy harvesters or thermoelectric generators to minimise maintenance and extend battery life – with the possibility of completely eliminating external power supplies, but only if the power consumption of the system is small enough and a capacitor is employed for energy storage.

In many applications, solar cells are the most familiar and relatively mature choice for low-power network nodes operating outdoors or under good indoor light conditions. However, other technologies suitable for extracting small amounts of power from the ambient environment exist. For example, a wireless sensor node set up to monitor bearing wear in a generator could employ a piezoelectric crystal as a vibrational energy harvester, converting motor vibration into usable energy, or a thermoelectric generator mounted on a hot exhaust could harvest a small amount of otherwise wasted energy from the thermal gradient.

Typical vibrational energy harvesters usually operate with a cantilever of piezoelectric material that is clamped at one end and tuned to resonate at the frequency of the vibration source for optimal efficiency – although an electromagnetic transducer can be used in some cases. Whilst the electrical power available is dependent on the frequency and intensity of the vibrations, the cantilever tip mass and resonant frequency can generally be adjusted to match the machinery or system that energy is to be harvested from.

Furthermore, energy harvesting management ICs that manage the accumulation of energy in a capacitor over a period of time can enable short bursts of relatively high power consumption, such as when a node wakes up and transmits a burst of data, and are particularly well suited to low-power wireless sensor nodes.

Even with the examples mentioned above, the energy-efficiency possibilities are significant and can be a reality. When designing prototypes or proof-of-concept demonstrations you may put energy use to one side, however when it comes time to generate a real, final product – you can only benefit from taking energy-efficiency into account.

If you are considering creating or modifying existing designs and not sure about the energy-saving and generating options that are available, be efficient and discuss your needs with an organisation that has the knowledge, experience and resources to make your design requirements a reality such as here at the LX Group.

At the LX Group we have a wealth of experience and expertise in the embedded hardware field, and can work with the new and existing standards both in hardware and software to solve your problems. Our goal is to find and implement the best system for our customers, and this is where the LX Group can partner with you for your success.

Published by LX Pty Ltd for itself and the LX Group of companies, including LX Design House, LX Solutions and LX Consulting, LX Innovations.

At the LX Group we say that smart energy is an exciting and important growth technology area, and that it encompasses and enhances a wide variety of existing and new technologies. Although many people consider energy to be a resource only limited by one’s capacity to pay the supplier invoice every three months – the ability to reduce energy consumption in an increasingly complex world is a communal goal.

Smart energy technology can be applied to a wide variety of devices used in the domestic, commercial and industrial areas – and benefits can of course be found in not only reduced energy consumption, but also in some cases by a reduction in the costs of installation and maintenance of smart energy hardware. In saying that let’s examine a variety of smart energy applications and their benefits.

Smart street lighting

Since their first installation, the use of electric street lighting has been a prime candidate for the smart energy devices due to the sheer volume of lamps and their combined energy use. Recenlt the ability to determine the ambient light level and illuminate accordingly provides light when necessary as well as saving energy. Further enhancements include replacement of lamps with lower-power LED equivalents that allow for a wider range of display levels. Finally by taking advantage of Zigbee wireless networking – lamps can not only be controlled remotely, they can also report lighting status data as well as error situations to a central computer. This removes the need for public response to broken lights and regular patrols – saving the utility time and money.

Energy harvesting

As more industrial and commercial applications rely on sensors, wireless transceivers and small microcontrollers for monitoring and data transmission, one of the design challenges has been powering and connecting these items to their required host. With regards to data transmission itself – the challenges have been overcome with the proliferation of low-power wireless mesh and point-to-point networking. And microcontroller manufacturers have reduced consumption by great lengths – in some cases down to micro amps by reducing CPU speed and smart sleep modes. These sleep functions can help when the power harvesting is sporadic, or takes time to generate enough energy for operation – for example when enough is available, the microcontroller can “wake up”, perform an operation such as transmit sensor data, then resume sleep until the energy levels resume at which point the process repeats itself.

Energy to run these devices can be harvested in many ways, however the three prevalent methods are:

Solar energy – a simple solution when the device is outdoors or can be wired to an external panel. A proven technology that can be used to charge various battery types and allows for 24/7 operation when the power drain is matched with an appropriate storage cell.
Mechanical energy – it is possible to transfer the energy from vibration and deformations into electrical currents suitable for low-power devices. An idea solution for constantly moving situations such as line-haul freight trains, mining system conveyor belts, and wave/tidal energy generators. These would also include a rechargebale battery to avoid power loss during short periods of down-time.
Thermal energy – Using sensors that consist of hundreds of tiny thermocouples, energy can be harvested from the difference between the ambient temperature and an external source of heat. These can include waste heat from industrial processes, climate-control systems and engine block heat. For example – with a sensor mounted on an area of 90 degrees Celsius, and an ambient temperature of 25 degrees – 10 mW of energy can be harvested – the equivalent according to sensor producer Micropelt of thirty AA cells per annum.

The Smart Energy Home

Domestic energy consumption is an issue for every householder, apart from rising energy bills the debate over climate change due to fossil-fuel energy sources and global warming has increasingly educated the population to reduce the energy consumption. The requirements to monitor consumption can be detailed due to the time of use and requriements for various appliances. Although utilities are installing smart meters which can offer various tariffs depending on the time of day – more can be done to assist the consumer.

The greatest advantage can be found by replacing appliances with new, energy-efficient units such as heat-pump electric hot water systems, however the cost can be substantial. A cheaper way is to offer real-time monitoring of each appliances’ energy use. This can be provided by a smart meter which can wirelessly transmit data to a receiver linked to a consumers’ PC or device – showing real-time consumption data. An option of increasing popularity is to sense the consumption of each major device in real-time – and in conjunction with time-of-use tariffs a true running cost can be shown – the greatest incentive to reduce energy use. These sensors can be fitted externall between the device and power outlet, or over time hopefully included within the device and working on a common Zigbee wireless standard.

As you can see there are many methods of smart energy use, including generation, intelligent consumption and better devices. All of these methods and more can be harnessed and modified for your individual requirements. Here at the LX Group our team has a range of experience in smart energy key technologies, including:

Displays and various user interfaces
Logging and data management
Remote monitoring and control
Ultra-low power wireless systems including mesh networking topologies
ZigBee-based networking, using Ember, TI, Jennic and Microchip platforms
Low unit cost design and BOM cost optimisation

And the team at LX has won national and international awards for past ZigBee-based systems.

For more information or a confidential discussion about your ideas and how we can help bring them to life – click here to contact us, or telephone 1800 810 124.

Published by LX Pty Ltd for itself and the LX Group of companies, including LX Design House, LX Solutions and LX Consulting, LX Innovations.