使用超低功率亞GHz無線自供電智能家庭網絡

　　本文闡述了如何在超低功耗無線收發器在低于1 GHz的頻段，KNX協議可以應用在智能家居實現自供電網絡，使用能量采集或長壽命電池的應用如照明和監控。

　　智能家居中低成本無線網絡的新標準正在為創新設計開辟機會。隨著最新的無線收發器和微控制器，超低功耗的設計，可直接由太陽能電池板通過能量收集可以開發。

　　而不是使用一個2.4 GHz的收發器單芯片，開發人員正在尋找低成本，低功耗收發器在ISM頻段的240 - 960兆赫，再加上8 -或16位超低功耗微控制器和新的協議。較低的頻率提供了更長的距離和更低的功耗，而KNX協議是在低功率聚焦智能家居設備進行了優化，開放的自供電設備和集線器的機會。

　　KNX協議是目前使用在歐洲的智能家居設備70%、尋址市場估計超過6億僅在歐洲€。作為一個開放的標準，KNX促進互操作性，節約了成本，提高了產品開發和設備所有者的靈活性。現在通過KNX協會管理，為國家CENELEC EN 50090和EN 13321-1岑歐洲、GB／Z 20965在中國，ANSI/ASHRAE 135在美國和全球的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.