基于I^2C总线的多点温度采集系统设计

Design of Multi-point Temperature Gathering System Based on I^2C-bus

采用基于I2C总线的设计,工作模式为单主机多从机,以实现对多点温度的采集、读取与显示。主机由P89LPC922单片机、数码管显示模块、电源模块、报警模块、键盘模块等组成,通过按键确定进入温度测量状态,从总线上读取节点温度值并显示,时钟使用单片机内部的实时时钟RTC、外部6MHz晶振,CPU掉电运行,每0.5 s唤醒一次。从机由LM75A数字温度传感器等组成,采集节点实时温度值,响应主机的请求发送温度数据。系统结构简单,操作方便,测量精度高,速度快,并具有报警功能,是一个综合处理多点温度信息的测量系统。

Based on the designing features of the I^2 C-bus, this system design takes the working patten of individual master and multi-slave to realize the collecting, fetching and showing of multi-point temperatures. The master is composed by microcontroller P89LPC922, showing module , power module , warning module , keyboard module etc. Entering the temperature measuring state and the following fetched temperature points by pushing the button to ascertain, the master reads nodal temperature value from bus and shows. The clock uses the inner Real- Time Clock （RTC）, the 6 MHz External Crystal Resonator of the microcontroller to realize the CPU power-down operation and the rousing of every 0.5 second. Slaves are composed by two Digital Temperature Sensor LM75A chips to fetch the real time temperatures and send the temperature data to response to the master. With simple, convenient operation, high measurement accuracy, speed, and Mann function, the system is an integrated multi-point temperature measurement system.