Z-Wave is an international standard for wireless communication in smart homes. It is based on ITU G.9959 specification and defines all aspects of the communication to ensure interoperability of devices implementing the protocol. This article describes the development process for hardware, SoC firmware, host communication and the certification and gives a good overview how to get started developing products for the Z-Wave ecosystem.
1. What is Z-Wave? Z-Wave has become the new star on the horizon of smart home technology with now more than 700 interoperable devices in the market. It opens a great opportunity for newcomers to add smart and new ideas to this large ecosystem of interoperable products and leverages the existing installed base.
This article describes the development process and the tools available to design and test Z-Wave compatible devices. Technically, Z-Wave is a specification for a low bit-rate communication protocol that allows different devices in buildings to communicate with each other wirelessly. These devices include fix-installed gear such as light switches and heating control, mobile devices such as remote controls and also gateways to Internet-based services on mobile phones or in the Internet. The specification covers all aspects of the communication from the radio layer up to the way devices generate events and execute actions. Only devices with complete implementations of all aspects of the communication protocol are called Z-Wave compatible or short a Z-Wave certified device.
2. Hardware To support the Z-Wave radio layer a special Z-Wave transceiver hardware is needed. The main supplier for this transceiver is the US company Sigma Designs. A second supplier, Mitsumi Corporation, offers a function and pin compatible silicon [Mitsumi2012]. The current chip generation of Sigma Designs is called Series 400 with the ZM4101 as standard component. Sigma or Mitsumi do not sell separate radio transceivers but the radio as one part of a whole SOC. The radio transceiver is available as a chip to very high volume applications where it can be embedded in the base designs but most customers purchase a SOC that integrates all functions of a computing system with radio interface:
• CPU Core, compatible to 8051
Figure 1: Z-Wave radio transceiver from Sigma Designs
Figure 2: Z-Wave Module ZM3102 based on Series 300 Transceiver ZW0301
• Radio transceiver with receiver and transmitter • 2 KByte ... 16 KByte Internal SRAM? • 32 KByte ...64 KByte ROM? • Several Peripherals
Figure 1 shows the Z-Wave transceiver Series 400 chip from Sigma Designs as an example.