Energy Harvesting and Wireless Networks

On June 10^th 2008, Green Peak Technologies launched a new ultra low power communication controller. The Emerald GP500C is an IEEE 802.15.4 standard compliant chip which is designed to be coupled with energy harvesting devices in wireless sensor networks. The GP500C is a standards compliant communications controller that incorporates a transceiver with a fully integrated communications layer and an on-chip energy manager. The device is able to drive and control the data without being driven by a microcontroller cutting down on overall system power consumption. The GP500C consumes a fraction (10-25%) of the energy of traditional microcontroller based designs and has a system sleep mode of below 100nA. This is a great step forward for developing battery free sensor networks.

GP500C

Light sensors reduce power consumption

Using a low power digital light sensor could help extend battery life for applications with power hungry displays. By automatically adjusting the dimming of a display based on the ambient light conditions, one can reduce the overall power consumption of the device. For this type of system, Intersil has great low power digital light sensors that allow access to information through a standard I²C interface. The ISL29010 and ISL29013 sensors measure and digitize the value of ambient light providing a simple way of integrating dynamic dimming into a device. These sensors are flexible and easy to use and allow you to choose the dynamic range and low-light sensitivity for your specific application. The supply current is 250µA however a power-down mode exists which only draws 1 µA. With some smart software control, these sensors can really make a difference in power consumption.

A NEW LOW POWER PIC!!!!!!

Microchip Technology claims to offer the lowest power 16-bit microcontroller which has a standby current of just 100nA. The PIC24FJ256GB1 family of microcontrollers include an integrated USB 2.0 peripheral and up to 256kbyte flash and 16kbyte RAM on-chip. Capacitive touch user interface designs are supported by an integrated charge time measurement unit and the supplier’s royalty-free mTouch Sensing Solution software development kit. The pricing for the device starts at $3.47 each in 10,000 unit quantities. This is very exciting news for anyone who is working on a battery powered embedded application.

 

PIC24FJ256GB1

Memristors could help create more power efficient electronics

Researchers at HP Labs have demonstrated the existence of a fourth basic element in integrated circuits know as a memristor. Systems utilizing the memristor’s capability of memory retention without power could make it possible to develop far more energy-efficient computing systems. Memristor-based computers would not require the energy consumptive process of booting up, instead they would turn on instantly using less power and possibly increasing system resiliency and reliability. They would be perfect for applications that require a lot of memory without a lot of battery-power drain. A mathematical model and a physical example that prove the memristor’s existence appear in a paper published in the April 30 issue of the journal Nature.

Short Video on the memristor

Lowering Power in your Logic

If your design has the right condition, a multiple Vdd design could save you a bunch in power consumption. The basic idea behind having multiple power supplies is to lower the operating voltage of appropriate logic gates which naturally will cut down on the power dissipation through those gates. The gates that operate from the lower voltage pay the price of becoming slower. So the trick is to find the appropriate logic paths in your design that are not time constrained. For example if you have two logic paths operating simultaneously one consisting of 4 gates and the other of 8 and the result of both is needed to continue operations, the path with 4 gates is a perfect candidate for scaling its voltage. You can lower that path’s voltage supply effectively slowing it down, which in this case does not make a difference in the overall design since the outcome of the 8 gate path has to be processed anyway. There are many reasons for not slowing the whole logic system down but one to consider is that in most (not all) cases it is good to get things done quickly and go back to sleep or low power mode. Since we can not slow down the whole system there is a need for multiple power supplies. There are however overheads with this, for instance you will need level shifters when two different voltage level logic paths converge into a new logic function, and obviously there are costs in designing two different power supplies. However if power consumption is the underlining design specification, this technique can help.

Practical Guide to Low-Power Design - User Experience with CPF

Power Forward Initiative (PFI) has a publication of “A Practical Guide to Low-Power Design – User experience with CPF.” The guide provides examples of low power design using the Silicon Integration Initiative (Si2)-standard Common Power Format (CPF) in a holistic low-power design environment. This is a guide for integrated circuit (IC) designers and will help efficiently achieve the best possible power savings with a minimal learning curve. 

 

 The Guide

Small and efficient WiMAX

Altair Semiconductors have developed what they claim is the world’s smallest and most power-efficient mobile WiMAX processor. The ALT2150 uses 142mW for a 1Mbps FTP upload, 125mW for a Streaming H.264 video, 81mW - VoIP call and 98mW in standby mode which is about half the power that is used by the competition. The chip implements full Wave-2 physical and Media Access Control (MAC) functionality. Altair’s product strategy exclusively focuses on battery operated devices and this is the reason for its excellent efficiency. Check out their webpage for more information.

Altair ALT2150

Battery-free Wireless Sensor Networks

Energy harvesting is increasingly gaining popularity and momentum across many different market spaces. When it comes to combining energy harvesting with wireless networks EnOcean and Green Peak are on the forefront. EnOcean provides battery free wireless sensor networks that are capable of transmitting some 300m with just 50 microjoules of energy. These sensor modules harvest tiny amounts of energy from their surrounding sources such as linear motion / pressure, light, temperature change, rotation and vibration. GreenPeak offers a similar technology which can be easily integrated into existing products. Their tiny wireless module integrates a transmitter/receiver, antenna, and low-power mesh network software on a single device. The module’s software can be configured to manage the power of different types of energy harvesting devices. OEMs can also add their own applications to the module, thereby eliminating the need for an external processor. A great example of how this technology can be used is the new 57-story Torre Espacio skyscraper in Madrid which uses 4,200 wireless buttons to control its 4,500 lights, thereby enabling all interior walls to be moveable without rewiring any light switches and at the same time providing a platform for intelligent power management of the building. Green intelligent buildings can save up to 30% energy as well by replacing batteries these devices eliminate toxic waste from disposed batteries which is also a great improvement to the environmental footprint that we are leaving. I believe that energy scavenging will become increasingly popular across all industries, and add more flexibility to low power oriented designs. Take a look at these truly innovative companies:

EnOcean

GreenPeak

Atmel’s high-performance ultra-low power microcontrollers

Atmel® Corporation has introduced the AT91SAM7L series of high-performance, ultra-low power microcontrollers. The microcontroller incorporates a wide verity of innovative techniques giving you the tools to optimize your system for maximum power savings. In active mode, the power consumption is optimized via a programmable operating voltage, operating frequency, peripheral clock activity, and the use of DMA instead of the CPU for data transfers. While in the different standby modes the power consumption can be controlled via power switches, scalable voltage regulators, and the use of sampling techniques on Voltage Monitors, Power On Reset and Brown Out Detector. Three different standby modes are available, the power down mode, the backup mode, and the wait mode. Power down mode only supplies power to the fast wake up pin. In backup mode only the supply controller, the zero-power POR and the 32kHz oscillator remain running while you have the option of setting the RTC, the 2K backup SRAM, the BOD, the charge pump, the LCD voltage regulator and the LCD Controller to on or off. Finally, in wait mode the 2MHz RC oscillator provides a rapid wake-up time for fast external event management. In single supply mode which can go down to 1.8V the current is 0.5mA/MHz while in power down mode the AT91SAM7L typically consumes 100nA. Assortments of peripherals are available with this microcontroller along with a development board. Definitely, this is a great platform to considering when starting a low power embedded project. Check out the Atmel Press Room for more information, and links to the evaluation kit.

Atmel Press Room

Intel’s Silverthorne Processor for MIDs

ntel has revealed some new technical information about their new low-power processor targeted at the MID (Mobile Internet Device) space. Rather than being a low power version of their existing processor, Silverthorne is an entirely new micro architecture. The processor will be Intel’s smallest in 15 years and is based on their 45 nm high-Kmetal gate technology. Silverthorne is a 64-bit, multithreaded processor with a 16-stage, in-order pipeline. The power consumption will be between 0.6 to 2 watts and will deliver between 1 to 2 GHz of performance. Silverthorne is expected to become available sometime in the second quarter of 2008.

 

Low Power Frequency Control

Fox Electronics is one of the leading supplier of frequency control products. Its products feature small size and low power consumption. For example the F230 12 MHz series oscillators requires only 7mA of input current during full operation and only 5µA of power during standby operation. These oscillators are said to be the industries smallest, making them perfect for space constraint portable applications.

 

Fox Electronics

Market Leading Power Consumption, 8-Channel ADCs

The ADS5281 from Texas Instruments is a family of 10- and 12-bit, eight-channel analog-to-digital converters (ADCs) featuring the industry’s lowest power consumption and smallest size. Capable of speeds up to 65MSPS and offering low noise performance and advanced digital features the ADS5281 is perfect for portable applications. The power consumption is 30 percent less than competing solutions. At the highest sample rate of 65 MSPS, the ADS5281 family consumes as little as 77 milliwatts (mW) per channel. With dynamic scaling, at a 30 MSPS sample rate, the per-channel power consumption is as low as 48 mW per channel.

Lowest Power, 8-Channel ADCs

Low Power Design Symposiums 2008

I attended the ISLPED Low Power Electronics and Design symposium in 2007 and found it to be excellent. There were a lot of interesting papers presented and I did learn a few low power design techniques that I since applied in my own designs. This year the symposium is being held in Bangalore, India sometime in early August. There is a WikiCFP up design to organize the calls for papers. Also the NanoPower Forum will be held in Irvine, California from June 2nd – 4^th. The primary focus of the forum is around “ultra low power” electronics. What I find most interesting is the talks and papers on energy harvesting techniques and applications. I think this will be a great event, so if you’re interested in the low power world, make sure to keep those days open.

ISLPED 2008

NanoPower Forum

10 times more charge for lithium-ion batteries

A group or researchers have formulated a way of increasing the capacity of lithium-ion batteries. The team lead by Yi Cui at Stanford University, has build a substrate out of silicon nanowiers capable of holding ten times more lithium compared to a carbon solution. Ten times more lithium means 10 times more charge. The findings are discussed in a paper published in Nature Nanotechnology on December 16th titled “High-performance lithium battery anodes using silicon nanowires.” This new technology is exciting because not only could it be applied to consumer electronics, but more importantly in applications such as electrical cars or storage devices for solar energy. A patent has been filed and hopefully the technology can become available shortly.

Low Power Microcontrollers

While browsing a microcontroller discussion board about the outlook on Low Power micros for 2008, I came across a very innovative company. Energy Micro is a company with a mission dedicated to energy efficiency. The mission is to develop, market and sell the world’s most energy efficient microcontrollers. I believe that this company has the right idea to succeed in the long-term especially because power consumption is becoming a primary design constraint. Take a look at the company webpage for more info, as well there are some opportunities for employment that could be very interesting.

Energy Micro

Intel’s New Low Power Storage Drive

Intel introduced a new, thumbnail-sized solid state storage drive designed for embedded applications in numerous portable electronic devices. The Z-P140 PATA Solid State Drive is a low-power, high-performance NAND flash-based storage drive. The 2GB and 4GB versions will be available early in 2008; 8GB and 16GB versions are expected out later in 2008 or in 2009 and Intel also projects that they can produce a 64GB version by 2010. The Z-P140, which features 40MB per second read and 30MB per second write throughput, has performed 30 percent faster than comparable hard drives in testing and uses 75 percent less power to do it. At idle 1.1mW are drawn and 300mW typical in operation. Check out Intel’s webpage for more info.

Intel’s Z-P140

Regulator for low voltage applications

Micrel offers the MIC38300 which is an efficient 3A step down converter. This converter merges the benefits of LDOs in respect to ease of use, fast transient performance, high PSRR and low noise while offering the efficiency of a switching regulator. By combining a switcher whose output is slaved to the input of a high performance LDO, high efficiency is achieved with a clean low noise output. The MIC38300 operates with input voltages from 3.0V to 5.5V and offers adjustable output voltages down to 1.0V. Check out Micrel’s webpage for more details and links to other low power components.

Micrel MIC38300

Jan Rabaey’s roadmap to low power design

     Professor Jan Rabaey of UC Berkeley gave the keynote address, on “Scaling the Power Wall, Revisiting Low-Power Design Rules.” at the International Symposium on System-on-Chip in Tampere, Finland. He noted that power consumption has been addressed as an issue in the past and that there were two proposed solutions to the problem. Allowing power-supply voltage to be a design variable, and to use new low power design techniques. Supply voltages have been dramatically reduced and most designs go below 1V. However, Rabaey suggest that we made spotty progress in using new low power techniques such as matching computation to architecture, preserving data locality, exploiting signal statistics and supplying energy on demand. Instead of matching computation to architecture, most chip designers fit computation problems to fixed architectures. There is inappropriate use of global data buses to move data around on the chip. There has not been any exploitation of signal statistics. The most used technique has been supplying energy to circuits on demand, mostly through clock gating. This technique has succeeded because of the availability of automated EDA tools that can do this job. The rest of the new design techniques require mental intervention and are not automated, hence their lack of adoption. Moreover, we have missed the importance of standby power. Supply voltages now approach transistor threshold voltages and as a result, large numbers of leaky transistors inhabit big nanometer chip designs.
     There is some good news; EDA companies are starting to form a low-power design methodology. This is driven by the fact that power is now the dominant design constraint. For example, data center costs for Web-centric companies such as Google are now dominated not by equipment or by plant costs but by energy costs. At the small end of the design spectrum, mobile devices are now completely defined by their available power budgets. In the past Technology scaling was a solution but according to Rabaey it will no longer help. This is because of silicon’s fundamental limits. Although active power density continues to be somewhat limiting, leakage power, which is growing at the same rate as computational power, is the killer. At the same time, technology scaling is actually causing more design pain—in the form of process variability, which drives chip designers to adopt wider design margins or face lower manufacturing yields. Smaller circuits are also subject to more soft errors from many causes.
     Rabaey suggests the following techniques for a successful electronic design:

• Concurrency galore
• Always-optimal design (no energy waste, ever)
• Better-than-worst-case design (accommodate computational and memory failures)
• Ultra-low supply voltages
• “Exploration of the unknown”

Concurrency is a good idea because it drives clock rates down, which can help save energy by allowing a further reduction of supply voltage. Always-optimal design attempts to optimize at design time, during run time, and during sleep modes. This approach requires additional circuitry. Better-than-worst-case design (also called aggressive deployment) moves design from the use of “design corners,” essentially worst-case design, to one where circuits operate in statistical operating regions where some errors are tolerated. This design approach requires the use of error-detection and –correction circuits. Ultra-low-voltage design recognizes that the true operating limit for a MOSFET is actually about 35 mV. Rabaey suggests that we can more closely approach this limit by rethinking all of digital logic. He suggested stacked transistors and logic design based on transmission gates as likely areas for productive research. Exploring the unknown employs radically new architectures that might employ millions of small processors on a chip, arrayed in collaborative networks. Experiments with search and recognition algorithms suggest that such imprecise networks of estimating processors might produce excellent results with very low energy consumption.
 

Source: http://www.edn.com/blog/980000298/post/370017637.html

Wireless Power

Broadcasting power through RF and using it to power electronic devices is not a new idea. This concept has been around for a long time, for example at the St. Louis World’s Fair in 1904 a prize was offered for a successful attempt to power a 75 W motor by energy transferred through space at a distance of 30m. However, for both technical and health reasons, wireless power transfer technologies have not yet made a stand in consumer electronics.  Focused beams of radiation are definitely a health safety risk, and energy bouncing of walls at different frequencies and voltage levels is difficult to capture as a steady voltage source. However, for low power applications there is hope. There are a few companies that have developed technologies that transmit power at safe levels making it possible to transfer energy to low power devices wirelessly. There are still major limitations to the technology. For instance, the distances that energy can be sent is limited to only about a meter and the amount of energy that can be transferred is limited to levels that can be used to recharge nothing bigger than a cell phone battery. But with electronics becoming less power hungry this could all change. Check out some of the start-up companies that are actively pushing the limits of this technology.

Powercast
Ecoupled

Qualcomm IMOD displays

IMOD display technology is based on the unique light-bending qualities of butterfly wings. Using advanced biomimetics, the technology maximizes the use of ambient light. The displays only need to use supplementary lighting in dark environments making them more energy efficient. For more information, go to the Qualcomm product brochure.

 

Product Brochure

New memory is 1000 times more energy efficient than flash

A new type of computer memory called programmable metallization cell (PMC) has been developed by researchers at Arizona State University. The memory is said to be 1000 times as energy efficient as flash memory and bit per bit one-tenth the cost. Within 18 months, the new technology is said to deliver a thumb memory drive capable of holding a terabyte (TB) of data. The technology is based on manipulating charged copper particles at the molecular scale. Copper bridges are formed between two electrodes to represent a binary 1, and the absents of a bridge represents a binary 0. The bridges are formed by applying a negative charge to the material which than transforms into copper atoms lined up to form a nanowier, the process is reversed with a positive charge. Besides the huge increase in memory capacity, this technology is exciting due to its power efficiency. By decreasing the energy consumption, portable devices will start to see longer battery lives. This extra life time will defiantly be needed to fill a terabyte thumb drive. Also, its going to be interesting to see how this technology will transform the laptop computer industry. For more information on PMC technology, visit the Axon Technologies web-page.

Axon Technologies 

NiMH, Li-Ion or Li-polymer? What to consider…

Nickel-Metal Hydride, Lithium Ion, and Lithium Polymer are the three main battery chemistries dominating the portable electronics space. All three types are capable of supplying the high power demand of portable applications. To make an optimal battery selection for a design one has to have a full understanding of the application and the unique strengths and weaknesses of each battery. Basically one needs to match the specific chemistry characteristics of the battery to the real life portable application’s usage specifications. So voltage, cycles, load current, energy density, charge time and discharge rates to temperature ratings, discharge profiles, charging cycles, expected shelf life and transportation requirements. Here is a brief overview of the different chemistries and how they match up to some of the real life usage specifications.

Nickel-Metal Hydride (NiMH):

Nominal cell Voltage: 1.25 V
Cycle durability: 500-1000 Cycles
Energy/weight: 100 Wh/kg
Energy/size: 140-300 Wh/L
Power/weight: 250-1000 W/Kg
Charge/discharge efficiency: 66%
Energy/consumer-price: 1.40 Wh/US$
Self-discharge rate: 30%/month
Optimal load current: <0.5C
Maximum aggregate voltage: 12.5 (10 cells)
Charge Time: <4 Hours

Lithium Ion (Li-Ion):

Nominal cell Voltage: 3.6/3.7 V
Cycle durability: 1000-1200 Cycles
Energy/weight: 160 Wh/kg
Energy/size: 270 Wh/L
Power/weight: 1800 W/Kg
Charge/discharge efficiency: 99%
Energy/consumer-price: 2.8-5 Wh/US$
Self-discharge rate: 5-10%/month
Optimal load current: <1C
Maximum aggregate voltage: 25.2 (7 cells)
Charge Time: <4 Hours

Lithium Polymer (Li-polymer):

Nominal cell Voltage: 3.7 V
Cycle durability: <1000 Cycles
Energy/weight: 130-200 Wh/kg
Energy/size: 300 Wh/L
Power/weight: 2800 W/Kg
Charge/discharge efficiency: 99%
Energy/consumer-price: 2.8-5 Wh/US$
Self-discharge rate: 5%/month
Optimal load current: <1C
Maximum aggregate voltage: 25.2 (7 cells)
Charge Time: <4 Hours

 

Knowing the battery specifications is important but not enough to make the ideal battery selection for a portable device. One has to consider the following real life usage specifications.

Temperature Range:

Firstly, here are some typical operating temperature ranges:

Consumer: -20°C to +60°C (-4°F to + 140°F)
Industrial/Military: -40°C to +85°C (-40°F to +185°F)
Automotive: -40°C to +115°C (-40°F to +239°F)
Geophysical: 0°C to + 150°C (32°F to +302°F)

The cell capacity changes with temperature and these variations can be quite large. Higher temperatures allow for a reduction of the batteries internal resistance, this increases the effective capacity of the battery. However a continuous exposure to high temperatures will shorten the cycle life of the battery along with increasing the self-discharge rate (cell degradation). At lower temperatures the cell capacity is reduced, also batteries have a tendency not to perform well in cases were instantaneous pulses of power are required mostly do to the increased internal resistance. One has to look at the average and extremes of their operating temperature rang and compare them to the various temperature curves provided by the manufacturer. Also the batteries have a tendency to heat up when charging so one has to take this into consideration when creating the PCB layout for the design.

Discharge Rate:

A discharge rate also has an effect on the amount of heat generated by the battery. The larger the load current the more heat generation exists. Also the batteries will perform better with a more uniform discharge pulse rate. Spikes in the power profile should be minimized; this goes for all three chemistry’s..

Charging Regimens:

The batteries heat up as they are charged. For example a typical NiMH battery will increase by +25 C while a Li-Ion will only increase +10 C with the same constant-current, constant-voltage charge method. This has to be considered especially for consumer portable devices.

Expected Shelf Life:

One has to consider how long the device will be in storage before being used. This makes a huge difference between NiMH and Lithium batteries. A NiMH battery could be completely dead within half a year without even being used. Lithium batteries have much better performance in this consideration.

Transportation Guidelines:

Transportation requirements are especially important for lithium based batteries, since there are strict regulations imposed on their transportation. Sometimes one has to two different battery designs one for local distribution and one for overseas.

Overall there is plenty of material available on the Internet and through the different battery manufactures that should help you make the optimal battery decision. The important part is just to know that that decision has to be made and that it’s not as simple as choosing based on price.

Zero emission-computer

According to sources used by Zonbu a standard PC consumes an average energy of 175 W which translates to 2071 pounds of CO2 emissions or 107 gallons of gasoline per year. However if your computing needs are limited to surfing the Web, e-mail, music and movies, chatting over IM, and office applications such as word processing and spreadsheets, than you may help the environment by using a Zonbu. The sleek and quiet (no fan) Zonbu device operates at 15W which equates to under a pound of CO2 emissions a year. However, this is a little misleading; the Zonbu may only consume 15W at your house, but since it contains no hard drive instead only having 4 GB of local flash memory, most of your data needs to be stored online. This means that energy is also consumed at some server farm, in this case Amazon’s server farms. Since server farms are becoming more efficient, with companies like Google leading the way, the CO2 emissions will still be below the 2071 pounds.

For only 99$ and an extra $12.95 a month to get 25 GB of online space, $14.95 for 50 GB, and $19.95 for 100 GB, I think the Zonbu is a great device to parallel with your existing MAC or PC. The monthly payments should be mostly offset by the savings on your electricity bill. The device operates on a Linux based system with the same feel as Windows, having programs such as Firefox, iTunes-like music and movie playing application, Skype, email, instant messaging software, OpenOffice, which is an office suite compatible with Microsoft Office with a word processor, spreadsheet, presentation software and more. Basically all you need for your everyday computing.

I’m sure there are a few innovative low power design techniques used to generate such impressive power results however probably most of the savings come from the lack of a proper hard drive and the low-power Intel-compatible processor made by the Taiwanese firm VIA. Hopefully as the design matures and all the little annoying problems that come with any new system are resolved, Zonbu like devices will be operating in every home. Check out their webpage for more info and ordering information.

 

 

Zonbu

SuperCaps to Smooth out the Spikes

So you managed to cut down on active and standby power consumption, but your battery still dies quickly. What next? Well look closer at your power profile; are instantaneous pulses of power required? If so you can optimize further. Power spikes are strenuous on most battery chemistries. For instance alkaline batteries have a large equivalent series resistance (ESR) which causes an internal voltage drop when current is drawn. This means that the batteries ability to deliver short spikes of current is relatively poor, especially in cold conditions and as the battery gets older. The voltage drop will eventually be so significant that it may blackout the device, defiantly something that has to be avoided. If you want to avoid changing batteries often, a higher energy density power supply is needed. If you want to stick to the cheap and widely available alkaline batteries the best solution is to introduce a supercapacitor to the power supply. This is known as load sharing. The peak load on the battery can be reduced by placing a large value capacitor in parallel with the battery. For instantaneous loads the energy is supplied by the capacitor which than recharges during the inactive period. This considerably reduces the duty cycle, stress on the battery and the undesired voltage drop. Supercapacitors are perfect for the job because they have energy efficiencies that rarely fall below 90 per cent, can be charged extremely quickly and safely, can survive hundreds of thousands of charge-discharge cycles without significant degradation in performance. A test is described involving drawing 2A, 10ms pulses from an arrangement of three AAA batteries connected in series, at a rate of one pulse per second. The experimenters then measured the time taken for the battery voltage to drop below 3V. Circuits equipped with a supercapacitor exhibited up to four times the battery life of those using batteries only. This is a significant increase in battery life!!!! Adding a supercapasitor to your application should be relatively simple, without any serious design changes. However watch out for the higher current draw at power on, a simple current limiting circuit may be required. As well, a low voltage lock-out function should also be designed. Overall, with the amazing technological advances in supercapacitors it only makes sense to apply them to a pulse intensive application.

ZigBee!!!!!!

Here are a few companies that offer some easy to implement, low cost and low power ZigBee/IEEE 802.15.4 wireless solutions. For instance MeshNetics offers everything from ZigBee modules, embedded software to evaluation and development kits. There are four main benefits to ZigBee technology. Firstly, its low cost which makes it easy to justify extending wireless networking to even the simplest devices. Next, all ZigBee product have to adhere to a standard profile meaning that customers can chose vendors as needed. This increases competition and innovation hence the great solutions that are already out there. ZigBee also has the advantage of avoiding obstruction and range issues. The routers double as input devices and repeaters making it easy to form mesh networks. Also, transmission is automatically routed through an alternate path if there is a blocked node. This allows for communication to continue even when there is an unexpected link failure. Finally and most importantly, ZigBee devices are known for their low power consumption. Basic radios can operate at 1 mW RF power and are put to sleep as soon as transmissions are complete, making them practical for battery operated devices. Take a look at the following companies for great products.

MeshNetics
Digi
Ember 
TI ZigBee