Low Power，遠程，ISM無線測量節點

　　一種低功耗無線傳感器節點不必是短程或復雜的。本文介紹了一種簡單、廉價的雙芯片解決方案。

　　理想情況下，無線測量節點具有功耗低、范圍廣、易于連接到不同傳感器的特點。通過三個模擬設備，公司部分的組合，與＜70μ平均電流消耗智能測量節點，射程近1公里（自由空間），和數據率傳輸/分鐘是可以實現的，同時還保持一個16位的ADC性能（見圖1）。這使得電路適用于電池供電以及自動化和遙感等應用。

　　Figure 1： Low-power， long range， ISM wireless measurement node （simplified schematic： all connections and decoupling not shown）。

　　The ADuC7060 precision analog microcontroller has a low-power ARM7 core as well as a myriad of precision analog functions. The onboard multiplexer， digitally programmable gain amplifier （PGA）， voltage reference， programmable current sources， and 24-bit sigma-delta ADC allow almost any temperature and bridge sensors to be directly connected. In this case， a four-wire Pt100 （100 Ω platinum RTD） temperature sensor was chosen. Further details on the measuring circuit can be found in the AN-0970 Application Note.

　　The system consists of a low-power temperature measurement node that wakes once a minute， measures temperature， transmits this measurement at 10 kbps to the base node， and returns to sleep. The base node continuously listens for a package from the measurement node and sends this information to the PC via the UART for display in HyperTerminal.