使用超低功率亚GHz无线自供电智能家庭网络

　　使用超低功率亚GHz无线自供电智能家庭网络

　　本文阐述了如何在超低功耗无线收发器在低于1 GHz的频段，KNX协议可以应用在智能家居实现自供电网络，使用能量采集或长寿命电池的应用如照明和监控。

　　智能家居中低成本无线网络的新标准正在为创新设计开辟机会。随着最新的无线收发器和微控制器，超低功耗的设计，可直接由太阳能电池板通过能量收集可以开发。

　　而不是使用一个2.4 GHz的收发器单芯片，开发人员正在寻找低成本，低功耗收发器在ISM频段的240 - 960兆赫，再加上8 -或16位超低功耗微控制器和新的协议。较低的频率提供了更长的距离和更低的功耗，而KNX协议是在低功率聚焦智能家居设备进行了优化，开放的自供电设备和集线器的机会。

　　KNX协议是目前使用在欧洲的智能家居设备70%、寻址市场估计超过6亿仅在欧洲€。作为一个开放的标准，KNX促进互操作性，节约了成本，提高了产品开发和设备所有者的灵活性。现在通过KNX协会管理，为国家CENELEC EN 50090和EN 13321-1岑欧洲、GB／Z 20965在中国，ANSI/ASHRAE 135在美国和全球的ISO / IEC 14543-3。

　　The focus of the KNX standard （formerly EIB/Konnex） is home and building control. The most typical application areas are lighting， shutters， or heating and cooling. The standard covers the wired-media twisted pair， power line， and Ethernet. In locations not suitable for cabling， KNX-RF is used for wireless data transmission within a building. As the complete KNX standard， the wireless part KNX-RF is vendor independent， allowing a range of RF transceivers to be used alongside different microcontrollers. This is opening up opportunities for ultra-low-power designs.

　　The KNX Advanced Interface （KAI） is the main software component of KAI and provides the complete functionality needed for KNX devices. This contains all elements required by the KNX standard and is certified in several different configurations. KAI maps closely to the ISO/OSI reference model with a clear structure that separates between application-relevant parts， modular communication stack internal parts， media-dependent parts， and target-CPU related issues （Figure 1）。 Advanced implementation methods allow highly-efficient coding that leads to optimized resource usage. This is shown in a small footprint and the moderate resources needed. An application development with KAI relieves the burden of early decisions in the design process by simple configurability of the stack.