結(jié)合單片機(jī)和模擬前端實(shí)現(xiàn)PLC解決方案

　　大量的嵌入式系統(tǒng)，從電機(jī)控制到智能能源應(yīng)用都需要連接，而現(xiàn)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(guān)重要。然而，電力線通信需要強(qiáng)大的數(shù)字信號處理（DSP）和模擬前端（AFE），能忍受惡劣的信號環(huán)境的交流線路。然而，DSP功能的微控制器（MCU）結(jié)合AFE可以處理中的應(yīng)用。讓我們看看一個(gè)可能的單片機(jī)/ AFE組合相對于智能家居，設(shè)計(jì)和開發(fā)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(gè)智能家居的極好的概要。元素包括照明、暖通空調(diào)系統(tǒng)、家電和娛樂設(shè)備，這些設(shè)備都連接到家庭自動(dòng)化網(wǎng)絡(luò)。ZigBee等無線技術(shù)可以使某些網(wǎng)絡(luò)連接，但電力線網(wǎng)絡(luò)是家電等產(chǎn)品的明顯選擇。此外，公用事業(yè)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(wǎng)絡(luò)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.