摘要 气压计被广泛应用于国防领域、工业领域、医疗领域以及我们日常家庭生活中。本设计中就介绍了一种气压的实时显示设备。它是利用软、硬件基础知识,通过单片机与气压传感器的结合,使得在液晶显示器上显示出当前大气压值。本文详尽的描述了基于MPX4115气压计的软硬件实现过程。 设计是基于气压传感器MPX4115的精密数字气压计系统。通过气压传感器MPX4115获得与大气压相对应的模拟电压值,并经过电压/频率(V/F)转换模块转换为数字脉冲,通过单片机接收该脉冲信号,得到单位时间内获得的脉冲数,依据电压与频率的线性关系式计算出所对应的实际气压值,最后在单片机的控制下由液晶显示电路显示出实际气压值。 关键词:单片机;气压传感器;V/F转换器;液晶显示 Abstract Barometer is widely used in the defense sector, industry, medical fields as well as our daily basic knowledge of hardware and software, and through bination of SCM and pressure sensors, The current atmospheric pressure value is displayed by the article describes in detail the hardware and software based on MPX4115 barometer realization. An accurate digital barometer system is designed based on pressure sensor MPX4115. The system firstly gains the value of analog voltage corresponding to the atmospheric pressure by sensor MPX4115. Then the voltage signal is transferred into digital pulses using voltage/frequency transferring model. A single-chip is utilized in receiving the pulse signal, measuring the number of pulses received per unit interval, and in calculating the actual magnitude of pressure according to the linear relationship between voltage and frequency. Finally, controlled by the single-chip, the actual value of pressure is displayed by the liquid crystal displaying circuit. Keywords: MCU;pressure sensor;V/F transferor;LCD 目录 1 绪论 1 课题背景 1 技术概况及发展趋势 1 传感器的技术性能 1 传感器的发展趋势 3 数字气压计系统设计意义 5 2 系统总体设计 6 设计整体思想 6 系统总体框图 6 数据采集模块 7 数据采集模块的芯片选择 7 数据采集模块的原理图 7 气压传感器MPX4115的原理图 8 数据转换模块 9 数据转换芯片选择 9 数据转换电路部分电路原理图 10 LM331的原理 11 数据处理模块 11 数据处理模块的芯片选择 11 单片机部分的原理图 12 AT89C52引脚及功能 12 显示模块及芯片选择 15 显示模块的芯片选择 15 显示器LCD部分的原理图 15 LCD1602原理 16 电源模块的原理图 18 芯片78L05原理 19 总体原理图 22 PCB制作 22 3 软件设计 24 程序流程图 24 软件开发语言介绍 25 4 系统调试与仿真 26 伟福仿真介绍 26
