Low Power，远程，ISM无线测量节点

　　Low Power，远程，ISM无线测量节点

　　一种低功耗无线传感器节点不必是短程或复杂的。本文介绍了一种简单、廉价的双芯片解决方案。

　　理想情况下，无线测量节点具有功耗低、范围广、易于连接到不同传感器的特点。通过三个模拟设备，公司部分的组合，与＜70μ平均电流消耗智能测量节点，射程近1公里（自由空间），和数据率传输/分钟是可以实现的，同时还保持一个16位的ADC性能（见图1）。这使得电路适用于电池供电以及自动化和遥感等应用。

　　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.