基于AVR单片机捕获中断和热敏电阻的温度测量

Temperature Measurement Based on AVR Capture Interrupt and Thermistor

介绍一种类R-F转换频率测量温度的方法,由AVR单片机引脚输出的高低电平通过热敏电阻和标准电阻对电容充放电,并由外部输入捕获中断测量充电时间,然后单片机根据测得的时间和标准电阻阻值计算出热敏电阻的阻值,查表得到温度值。详细介绍了该方法的测量原理,给出了主要程序流程图和关键程序代码,并在一款温度计的设计中成功运用了该方法,实现低成本、高精度的温度测量。

The paper introduces a method of measuring thermistor temperature the similar to R - F convert frequency method,high level or low level output from AVR MCU charges up capacitance through thermistor and standard resistance, outside input capture interrupt measures charged time,and calculates resistance value of thermistor according to charged time and the value of standard resistance,get temperature value by means of table look- up. It discusses the measuring theorem, gives main program flowchart and key code. And this method is successfully launched in designing thermometer, realized lower - cost, high - precision temperature measurement.