25 October 2011
Reference design uses DECT ULE technology to target home automation
As the world goes mobile, taking advantage of the power of the smartphone, the rise of the 'app' is bringing almost unprecedented functionality. Through a combination of technologies, smartphone users can, in theory, control every aspect of their home, no matter where they are.
While that's the theory, Dialog Semiconductor is looking to spur the development of devices that enable this functionality with the launch of the SmartPulse IP gateway reference design. According to the company, which specialises in power management, audio and short range wireless communications, the reference design will allow DECT ULE home automation wireless sensor and actuator products to be connected to the web for remote management, not only by smartphones, but also by laptops and tablet pcs.
At the heart of the reference design is Dialog's SmartPulse SC14CVMDECT wireless base station device and SC14452 VoIP application host processor, which comes with 32Mbyte of flash memory, 16Mbyte of sdram, an Ethernet PHY and an Ethernet transformer.
Explaining the rationale behind the reference design, product marketing manager Jos Banderloop said: "Through the acquisition of SiTel, Dialog has expertise in the telephone business. We decided to use this expertise to build a complete reference design for VoIP deskphones and are now moving this into the residential market." The reason, Banderloop explained, was that most communication today is over the internet.
The reference design takes advantage of DECT ULE – the latest version of the cordless telephony standard. ULE – or ultra low energy – supports data and voice communications, but is intended to enable networks of wireless sensors and actuators to be supported by DECT. Targeted at home and enterprise applications, the approach is believed to be suited to use in such markets as home control, security and healthcare. A further market sector is tracking devices.
DECT ULE is a low to medium data rate technology, typically handling data rates of less than 1Mbit/s over short distances. Its attraction is that it is based on DECT, which has been continually enhanced since its introduction in 1993. Exclusive frequencies are reserved for the standard and chips are available from multiple vendors. A DECT network can support up to 300 nodes on one home gateway and is said to be interference free; the system uses the 'listen before talk' approach.
In domestic applications, DECT ULE networks are expected to link a range of devices; from white goods and lighting controls to door and window locks and smoke alarms.
Banderloop explained that Dialog had already created a DECT based residential phone for German communications company AVM. "We have also implemented DECT on routers for the company," he continued.
The attraction is that some 300million homes around the world already have DECT telephony. "By upgrading the DECT modem," Banderloop continued, "we can offer ULE based apps. Products based on this reference design can be used with any router that has an Ethernet port."
Measuring 60 x 100mm, the reference board is supported by Dialog's Rhea µClinux software development environment, which includes web servers, TCP/IP stack and an SSH server. Included with the reference design are two example sensor application boards, which connect automatically with the IP gateway reference design and enable the testing of web control systems for SmartPulse enabled products.
According to Dialog, Rhea is a versatile software platform that allows VoIP products to be developed quickly and efficiently. Along with a dual IPv4/v6 networking stack, to support future internet applications, it also features a BroadSoft certified SIP stack to provide a guaranteed level of interoperability. Alongside these stacks, Rhea provides a web server and an auto provisioning mechanism. These give the option of managing and upgrading products in the field.
To further simplify the design process for new wireless sensor network systems, Dialog has also announced development kits for its complete family of SmartPulse DECT ULE sensors (SC14WSMDATA, SC14WSMDECT) and base station (SC14CVMDECT) devices.
These kits, which include both devices and software, are said to provide a simple way for developers to create SmartPulse based systems, such as wireless controlled door locks, smoke alarms, light switches, home appliances and personal security and healthcare systems.
Launched in September 2011, Dialog's low power wireless sensor network devices are capable of running for up to 10 years on a single AAA battery and are certified for use around the world. Streaming 232bit data packets in the 1870 to 1930MHz licensed DECT band, the devices have a range of 300m, are self configuring and require no network planning.
Dr Asmund Tielens, general manager of Dialog's Connectivity and Automotive and Industrial Business Group, said: "DECT ULE is the key enabling technology for wireless sensor networks for home automation, healthcare, security and energy monitoring consumer applications. Our SmartPulse reference design and development kits will significantly speed time to market for customers entering these new markets."
Dialog is a cofounder of the DECT ULE standard and the SC14WSMDATA, SC14WSMDECT and SC14CVMDECT are said by the company to be the first commercially available DECT ULE devices, enabling the creation of home automation, security and energy metering devices that automatically configure with the base station, removing the need for network planning.
The SC14WSMDATA and SC14WSMDECT sensor nodes integrate the baseband, radio transceiver, antenna and power amplifier into a single system in package device. In sleep mode, the programmable devices consume less than 3µA. The SC14WSMDECT sensor also integrates audio functionality, enabling the creation of battery powered voice devices.
The SC14CVMDECT base station chip supports both voice and data, connecting with up to six voice and 256 data sensor nodes. Supporting the DECT ULE, DECT 6.0 and CAT-iq standards, the system in package device integrates a UART interface for external hosts.
Banderloop noted that all VoIP and SIP protocols are initiated from within the baseband device and that the only additional part needed is the Ethernet chip. "It's one of the cheapest solutions in the market," he claimed. "The Ethernet port also means that it can be used with any other device equipped with an Ethernet interface."
The attraction of the reference design, he continued, is that it enables any company or individual to define ULE based apps and to see them work with any router or modem featuring an Ethernet port.
While Dialog expects products developed using this reference design to be standalone devices, it also believes the design might be integrated into another device. "It depends on the customer," Banderloop noted. "The design is targeted at engineers who may not have DECT knowledge. It's easy to work with and you don't have to be dependent upon a DECT production line." In fact, the IP-Gateway integrates the familiar AT Command set, allowing wireless links between multiple sensors and the
base station to be configured.
The reference design is provided with schematics, supporting those who want to integrate the functionality into another product. "This makes it easier for the customer to produce the design anywhere," Banderloop concluded, "and Gerber files are also available on request."