文档介绍：基于AT89S51单片机的超声波测距仪设计
基于AT89S51单片机的超声波测距仪设计
内容提要:我们知道,当物体振动时会发出声音。科学家们将每秒钟振动的次数称为声音的频率,它的单位是赫兹。我们人类耳朵能听到的声波频率为20~20000赫兹。当声波的振动频率大于20000赫兹或小于20赫兹时,我们便听不见了。我们把频率高于20000赫兹的声波称为“超声波”。超声和可闻声本质上是一致的,它们的共同点都是一种机械振动。其不同点是超声频率高,波长短,具有方向性强、能量集中、不受光和电磁波以及粉尘等外界因素的干扰等优点。因此,超声波可用于非接触测量,利用计算超声波在被测物体和超声波探头之间的传输来测量距离的,对被测目标无损害。而且超声波传播速度在相当大范围内与频率无关。正由于这样,目前对于超声波精确测距的需求也越来越大,在机械制造,电子冶金,航海,宇航,石油化工,交通等工业领域具有广泛地应用。此外,在材料科学,医学,生物科学等领域中也占具重要地位。
本文主要介绍基于AT89S51单片机,辅助以CX20106A红外接收专用放大电路,TCT40-10超声波传感器和数字化的温度传感器DS18B20设计的超声波测距仪。测距原理采用一般的方法:渡越时间法TOF(time of flight)来测量物体与发声源的距离。测量距离大概5m,。
关键字:超声波渡越时间法 AT89S51 CX20106A TCT40-10 DS18B20

AT89S51 MCU-BASED DESIGN OF ULTRASONIC
RANGE FINDER
Abstract:We know that objects will sound when they vibrate. Scientists call the number of vibrations per second frequency of sound, its unit is the Hertz. Our human ears can hear the sound frequency between 20 ~ 20,000 Hz. When the sound wave frequency is greater than 20000 Hz or less than 20 Hz, we can’t listen it. We have higher than 20000 Hz frequency sound waves known as "Ultrasonic". The sound wave which we can listen and ultrasonic have the same essence, they are also a mechanical vibration. Their difference is that the ultrasonic have a high-frequency and a short wavelength, furthermore it is high directivity, concentrated energy, and free form light and dust, such as ic interference from external factors, etc. Therefore, ultrasound can be used for non-contact measurement, the use of ultrasound in the calculation of the measured objects and the transmission between the ultrasonic probe to measure the distance of the measured target without damage.
This paper mainly introduces single-chip based on the AT89S51, auxiliary CX20106A infrared receiver to a dedicated amplifier and TCT40-10 ultrasonic sensor designed ultrasonic range finder. Ranging general principle of the method used: transit-time method TOF (time of flight) to measure objects with the sound source distance. Measuring t