結合單片機和模擬前端實現PLC解決方案

　　大量的嵌入式系統，從電機控制到智能能源應用都需要連接，而現有的電力線可能為這種連接提供最方便的媒體。此外，電力線通信（PLC）可能對智能家居至關重要。然而，電力線通信需要強大的數字信號處理（DSP）和模擬前端（AFE），能忍受惡劣的信號環境的交流線路。然而，DSP功能的微控制器（MCU）結合AFE可以處理中的應用。讓我們看看一個可能的單片機/ AFE組合相對于智能家居，設計和開發工具，以及一些可供選擇的電力線通信電路。

　　圖1所示的德克薩斯儀器（TI）提供了一個智能家居的極好的概要。元素包括照明、暖通空調系統、家電和娛樂設備，這些設備都連接到家庭自動化網絡。ZigBee等無線技術可以使某些網絡連接，但電力線網絡是家電等產品的明顯選擇。此外，公用事業和智能電表之間的通信是最容易使用的PLC。無線和電力線網絡很容易通過橋梁連接。

　　Figure 1： In a smart home， power-line networks combine with wireless schemes such as ZigBee to link appliances， HVAC systems， and other network elements to a smart meter and the smart grid.

　　The smart-home concept includes elements that are primarily conveniences or luxuries， but also elements paramount to reducing power consumption and dodging a potential global energy crisis. Consumers would surely enjoy the convenience of programmable lighting control or the ability to remotely raise the thermostat on the hot tub. Those same control capabilities can slash energy use by ensuring that devices get powered off and by working with utility demand-management strategies.

　　Clearly the smart home concept is compelling， but there is an important cost angle as well. If the premium associated with adding communications capabilities to appliances and other home goods isn‘t affordable， the technology will not move forward. That cost angle is why it’s significant that relatively-low-cost MCUs can handle the task at hand.