Home Automation


Home Automation

Source: PG&E


As the Smart Grid enters mass deployment, consumers will see the emergence of energy-aware, intelligent home devices.  These devices will be able to respond to demand signals from the utility, enabling consumers to better control as well as reduce their energy consumption.  This will allow utilities better control during peak energy generation conditions and greatly reduce the investment required to sustain the world’s growing power needs.  Correspondingly, consumers will benefit in terms of energy cost savings from utilities avoiding this infrastructure investment and from pricing discounts provided by utilities to manage its peak loads. 


The range of device types and corresponding HAN requirements are large, as some products will compete to provide coordinator functions for the home while others implementing simpler end devices.  Currently, ZigBee is winning the race as the preferred Smart Grid HAN technology and according to Pike Research will represent over 90% of HAN technology shipped with Smart Meters between 2011 and 2015.


The following list is representative of this coming wave of devices:

  • In Home Displays
  • Programmable Communicating Thermostat
  • HAN Gateway or Energy Service Portal
  • Smart Outlet
  • Self Powered Switches
  • Smart Washer/Dryer
  • Smart Pool Pump
  • Smart Refrigerators
  • Smart Freezers
  • Gas Meter
  • Water Meter


The market opportunity is tremendous and according to a recent report from Zpryme “Smart Grid Insights: Smart Appliances”, the global household smart appliance market is projected to grow from $3.06 billion in 2011 to $15.13 billion in 2015.


Accent in the Home Area Network

As with Smart Metering, the ASMgrid1 SoC platform's flexible architecture as well as engagement model easily addresses the full range of smart appliances as described above. The following are only a few of the possible end-device applications supported through a customized ASMgrid1 offering:

  • Gas/Water Meter
  • Programmable Communicating Thermostat
  • Washer/Dryer/Refrigerator


Gas/Water Meter

While not a home appliance, one way gas and water meters will be enabled with AMR/AMI functionality is via home area networks. The rationale for integrating intelligence in these meter types is similar to electric meters. Gas and water electric meters share similar functionality to electric meters, namely a measurement function, wireless communications, microcontroller for running applications. As with an electric meter, a lower cost, lower power single-chip solution is possible with some modifications to the ASMgrid-enabled Smart Meter. In particular, since the water or gas meter will most likely communicate to a HAN using ZigBee Pro, the NAN functionality may be removed. Similarly, as the device is acting as end device versus a coordinator/gateway, on-chip memory requirements can be reduced compared to a Smart Meter configuration.


Programmable Communicating Thermostat

Programmable Communicating Thermostat Chart


At the lower end of cost and power spectrum of HAN enabled devices, is the Programmable Communicating Thermostat. While the processing requirements are reduced compared to a meter device, a Cortex-M3 or ARM7TDMI provides the necessary headroom to perform both the ZigBee Pro protocol processing as well as the application processing such as responding to demand response signals. 256 KB of FLASH provides the needed space for the application code, ZigBee PRO protocol stack, ZigBee Smart Energy Profile, as well as room to accommodate future possible changes in the ZigBee standard. By integrating the LCD controller and temperature sensor, ASMgrid1 dramatically reduces the number of parts required as well as the BOM.



Interest and activity around Smart Appliances has transition beyond the discussion stage and now is being tested in several pilot programs. A number of approaches are still in discussion on the best way to enable these capabilities for products such as washer, dryers, and refrigerators. The U-SNAP alliance is one such approach and has gained much support in promoting a universal communication interface that would enable equipment manufacturers to cheaply snap-in a circuit card with a technology of their choosing. At the semiconductor level, the resulting solution would communicate over a serial peripheral interface, common in most offerings and thus, minimize cost impact. Additional software requirements are also minimal. Thus, the resulting ASMgrid would require very little modifications to the previous example with the most notable exception being the elimination of a LCD controller.


Key ASMgrid Benefits Include:

  • Silicon-Enabled Differentiation: ASMgrid1's modular, configurable platform approach enables quick changes that match a customer’s product needs, whether the focus is cost reduction, performance enhancement, feature enhancement or all of the above.
  • Fast Time to Market and Low Risk: ASMgrid1's pre-integrated, pre-verified turnkey offering includes: ASMgrid1.0 reference silicon, hardware/software development tools, certified protocol stacks. Combined with Accent's production flexibility, Accent enables silicon mass production ramp in as little as 3-6 months versus years compared to a custom approach.
  • Fast Return-On-Investment: Accent’s pre-integrated ASMgrid1 Platform and turnkey software solution dramatically reduces up-front development cost, significantly increases production margins, and satisfies demanding ROI requirements on otherwise challenging product programs.