光电计数器的设计

总结与展望光电计数器的设计摘要本系统采用的是以单片机STC89c52为核心的自动计数器。

采用反射式光电传感器，将红外发光管与光电接收管相邻安放，每当物体通过一次，红外光就被物体反射，光电接收管接收一次，光电接收管的输出电压就发生一次变化，这个变化的电压信号通过放大和处理后，形成计数脉冲，通过光电隔离耦合并行输入至STC89c52单片机的P1口，通过软件控制和键盘设定计数值并用LED加以显示，便可实现对物体的计数统计。

本计数器可将机械或人工计数方式变为电子计数，并且采用LED数码管显示，可适用于诸多行业，以满足现代生产、生活方式的需求。

所谓的光电式传感器是将光信号转化为电信号的一种传感器。

它的理论基础是光电效应。

这类效应大致可分为三类。

第一类是外光电效应，即在光照射下，能使电子逸出物体表面。

利用这种效应所做成的器件有真空光电管、光电倍增管等。

第二类是内光电效应，即在光线照射下，能使物质的电阻率改变。

这类器件包括各类半导体光敏电阻。

第三类是光生伏特效应，即在光线作用下，物体内产生电动势的现象，此电动势称为光生电动势。

这类器件包括光电池、光电晶体管等。

光电效应都是利用光电元件受光照后，电特性发生变化。

敏感的光波长是在可见光附近，包括红外波长和紫外波长。

市场上的光电计数器采用的光电传感器有摄像头、光电管等，采用的光的种类有普通光和激光，可见光和不可见光等。

光电传感器一般由光源、光学通路和光电元件三部分组成。

光电式传感器是以光电器件作为转换元件的传感器，光电检测方法具有精度高、应用快、非接触等优点，而可测参数多，光电传感器的结构简单，形式灵活多变因此，光电式传感器在检测和控制中应用非常广泛。

【关键词】计数器光电传感器单片机数码管调研报告1.1当今生活是信息时代,是获取信息和处理信息,以及信息应用的时代.传感信息与检测技术的重要性在于它是获得信息并对信息进行一定处理的基础技术,是获取信息和信息加工处理的重要手段之一。

传感与检测技术是一门知识面广、综合程度高、实用性很强的专业课程。

它从传感器的基本理论入手，着重讲叙传感器的结构与感测原理，传感器是一个二端口的装置，不同的传感器输入-输出特性不同，同一传感器适应不同的被测信号呈现的特性也有所不同。

尤其当被测信号为静态信号时两种状态下，传感器的输入-输出特性完全不同。

感测技术在许多新知识里都有应用，以信息的传感、转换、处理为核心，从基本物理概念入手，阐述热工量、机械量、几何量等参数的测量原理及方法。

光电式传感器是将光信号转化为电信号的一种传感器。

它的理论基础是光电效应。

这类效应大致可分为三类。

第一类是外光电效应，即在光照射下，能使电子逸出物体表面。

利用这种效应所做成的器件有真空光电管、光电倍增管等。

第二类是内光电效应，即在光线照射下，能使物质的电阻率改变。

这类器件包括各类半导体光敏电阻。

第三类是光生伏特效应，即在光线作用下，物体内产生电动势的现象，此电动势称为光生电动势。

这类器件包括光电池、光电晶体管等。

光电效应都是利用光电元件受光照后，电特性发生变化。

敏感的光波长是在可见光附近，包括红外波长和紫外波长。

数字式电子计数器有直观和计数精确的优点，目前已在各种行业中普遍使用。

数字式电子计数器有多种计数触发方式，它是由实际使用条件和环境决定的。

有采用机械方式的接触式触发的，有采用电子传感器的非接触式触发的，光电式传感器是其中之一，它是一种非接触式电子传感器。

采用光电传感器制作的光电式电子计数器。

这种计数器在工厂的生产流水线上作产品统计，有着其他计数器不可取代的优点。

该例光电触发式电子计数器只有两位数，但通过级联可以扩展为四位，甚至多位。

1.2光电计数的现状及发展前景随着科学技术的发展，电子计数器的辅助功能也逐渐增加，现在已经出现了多功能计数器，多功能计数器产品的响应度较高，交直、流电两用、耗能低、价格低、无机械碰撞、无磨损、使用寿命长，既可计数，又可计算。

例如在毛衣编织机上运用，除可计数和计算外，还可实现断线报警。

通用计数器不仅可测频率、周期还可以测多周期平均、时间间隔、频率比和累计等。

频率计数器专门用总结与展望于测量高频和微波频率的计数器。

微波计数器是以通用计数器和频率计数器为主配以测频扩展器而组成的微波频率计。

它的测频上限已进入毫米波段，有手动半自动、全自动3类。

系列化微波计数器是电子计数器发展的一个重要方面。

由于有光电计数的设计理念，因此有了光电计数的发展。

在市场电子计数器行业需求增长有所减缓的现状下，产能扩张的势头并没有得到较好的控制。

产能过剩、重复建设不仅导致生产与消费的失衡，而且还引发了电子计数器行业内的一系列恶性价格竞争，影响了电子计数器行业业的盈利能力。

中国电子计数器行业市场现状，为外资企业入驻中国创造了条件，国际许多电子计数器行业企业已经看中在中国低成本拓展市场的机会，随着外资投入逐步加大，中国国内企业改革重组迅速加快。

同时新的行业制度等政策的颁布和实施将促使我国电子计数器行业洗牌，企业兼并重组将在政策的促使下大力发展。

由于当前电子计数器行业效益下滑，所以对电子计数器行业企业授信更要慎重。

必须关注电子计数器行业子行业，关注电子计数器行业上下游企业，优化客户结构，针对电子计数器行业行业需求进行新产品开发。

国内的制造技术水平远不如国外，制造技术不仅是衡量一个国家科技发展水平的重要标志,也是国际间科技竞争的重点。

我国正处于经济发展的关键时期,制造技术是我们的薄弱环节。

只有跟上发展先进制造技术的世界潮流,将其放在战略优先地位,并以足够的力度予以实施,才能尽快缩小与发达国家的差距,才能在激烈的市场竞争中立于不败之地。

总之,在我国研究和发展先进制造技术势在必行。

English translationHistory about ElectronicsThere can be no doubt that the1900s is remembered as the electronic century. Of course there have been other great advances. In transport in science in commerce and many other fields but where would they have been without the instruments and devices that electronics has provided? How would see a 3D virtual reality image of your beating heat with no electronics? How would you get money out of the bank on a Sunday night without electronics? Would you go to a pop concert that had no amplifiers. large screens or lighting effects? Do not say you would rather watch TV-there would not be any.Electronics in the early 20th century started thriving at a greater speed unlike the pre-20th century developments. The radio invented by the Italian genius Marconi and the work of Henry Hertz opened the road to further discoveries and inventions. In the first decade the new thing that was welcomed to the technical world was the vacuum tube. The vacuum tubes at that time worked as a miraculous component for the radio devices.The real electronics what it is called today was actually started after the discovery of the transistor effect. Transistor opened the road for the electronics and more importantly it opened the road for the computing world. Computers of various types started hitting the market and the research works got a boost.Because of the strong point of ultrasonic energy consumption, slow, medium of communication in the distance, which are often used for ultrasonic distance measurement, such as the range finder and level measurement can be achieved by ultrasound. Use of ultrasonic testing is often more rapid, convenient, simple, easy to achieve real-time control, and measurement accuracy can meet the practical requirements of industry, in the mobile robot has been developed on a wide range of applications.The strong point of ultrasonic energy consumption, slow, medium of communication in the distance, so I often use ultrasonic to measure distance, such as the range finder and object measuring instrument, ultrasonic range finder device is provided aiming point device, as long as the instrument alignment of the object to be measured, there will be a point in the range finder display screen, mainly through the velocity measurement, invisible to the naked eye injection line总结与展望Ultrasonic range finder for transmitting at the same time the beginning of time, the ultrasonic transmission in the air, the way to meet the obstacle immediately return, ultrasonic receiver receives the reflected wave is interrupted immediately stop the clock. Through continuous detection of generated wave emission obstacle after the echo reflected, in order to detect ultrasonic and receives the echo T time difference, and then calculated the distance L.Ultrasonic range finder, because ultrasound is largely influenced by the surrounding environment, so the general measurement with short distance, lower measuring accuracy. The range of use is not very wide, but the price is relatively low, generally a few hundred Yuan.①A principle of ultrasonic distance measurement1, the principle of piezoelectric ultrasonic generator Piezoelectric ultrasonic generator is the use of piezoelectric crystal resonators to work. Ultrasonic generator, the internal structure as shown in Figure 1, it has two piezoelectric chips and a resonance plate. When it's two plus pulse signal, the frequency equal to the intrinsic piezoelectric oscillation frequency chip, the chip will happen piezoelectric resonance, and promote the development of plate vibration resonance, ultrasound is generated. Conversely, if the two are not inter-electrode voltage, when the board received ultrasonic resonance, it will be for vibration suppression of piezoelectric chip, the mechanical energy is converted to electrical signals, it becomes the ultrasonic receiver.2, the principle of ultrasonic distance measurementwave in gas, liquid and solid medium with different velocity, good directivity, energy concentration, attenuation in transmission process, small reflection ability. The ultrasonic energy at a certain speed, bi-directional communication obstacles after the formation of reflection, using this characteristic, through the determination of ultrasonic wave and the time can calculate the actual distance, so as to realize the non-contact measurement distance of objects. Ultrasonic rapid, convenient, and not affected by light and other factors, are widely used in hydrological measurement of liquid level measurement, construction site, site location, vibration monitoring instrument vehicle back-draft obstacle detection of mobile robot, position detection and other fields. This digital ultrasonic range finder based on ultrasonic round-trip time is input to a counter for counting clock pulses of specific frequencies, and display the corresponding distance measuring.Ultrasonic transmitter in a direction to launch ultrasound, in the moment to launch the beginning of time at the same time, the spread of ultrasound in the air, obstacles on his way to return immediately, the ultrasonic reflected wave received by the receiver immediately stop the clock. Ultrasound in the air as the propagation velocity of 340m / s,according to the timer records the time t, we can calculate the distance between the launch distance barrier (s), that is: s = 340t / 2 In order to study and use of ultrasonic, people have designed and made a lot of ultrasonic generator. Generally speaking, the ultrasonic generator can be divided into two categories: one category is generated by electrical .a class is generated by mechanical ultrasonic. Electrical means includes a piezoelectric type, type and electric type; mechanical Garr flute, the liquid whistle and air siren. They are generated by the ultrasonic frequency, power and acoustic characteristics of each are not identical, so the purpose is also each not same. At present, more commonly used is of the piezoelectric type.②Ultrasonic Ranging System for the Second Circuit DesignSystem is characterized by single-chip microcomputer to control the use of ultrasonic transmitter and ultrasonic receiver since the launch from time to time, single-chip selection of 8751, economic-to-use, and the chip has 4K of ROM, to facilitate programming. To circuit schematic diagram shown in Figure 2. Draw only the front range of the circuit wiring diagram, left and right in front of Ranging Rang circuits and the same circuit, it is omitted.140 kHz ultrasonic pulse generated with the launchRanging system using the ultrasonic sensor of piezoelectric ceramic sensors UCM40, its operating voltage of the pulse signal is 40kHz, which by the single-chip implementation of the following procedures to generate.Ranging in front of single-chip termination circuit P1.0 input port, single chip implementation of the above procedure, the P1.0 port in a 40kHz pulse output signal, after amplification transistor T, the drive to launch the first ultrasonic UCM40T, issued 40kHz ultrasonic pulse, and the continued launch of 200ms. Rang the right and the left side of the circuit, respectively, then input port P1.1 and P1.2, the working principle and circuit in front of the same location.2, reception and processing of ultrasonicUse to receive the first launch of the first pair UCM40R, the ultrasonic pulse modulation signal into an alternating voltage, the op-amp amplification IC1A and after polarization IC1B to IC2. IC2 is locked loop with audio decoder chip LM567, internal voltage-controlled oscillator center frequency of f0 = 1/1.1R8C3, capacitor C4 Determine their target bandwidth. R8-conditioning in the launch of the carrier frequency on the LM567 input signal is greater than 25mV, the output from the high jump 8 feet into a low-level, as interrupt request signals to the single-chip processing.Ranging in front of single-chip termination circuit output port INT0 interrupt the highest priority, right or left location of the output circuit with output gate IC3A access INT1 port single-chip, while总结与展望single-chip P1.3 and P1. 4 received input IC3A, interrupted by the process to identify the source of inquiry to deal with, interrupt priority level for the first left right after. Part of the source code is as follows: receive1: push PSWPUSH accCLR ex1; related external interrupt 1INB p1.1, right; P1.1 pin to 0, ranging from right to interrupt service routine circuitINB p1.2, left; P1.2 pin to 0, to the left ranging circuit interrupt service routineReturn: SETB EX1; open external interrupt 1POP ACCPOP PSWRETIRight: ...; right location entrance to circuit interrupt service routineAIMP ReturnLeft: ...; left ranging entrance circuit interrupt service routine AIMP Return4, the calculation of ultrasonic propagation timeWhen you start firing at the same time start the single-chip circuitry within the timer T0, the use of timer counting function records the time and the launch of ultrasonic reflected wave received time. When you receive the ultrasonic reflected wave, the receiver circuit outputs a negative jump in the end of INT0 or INT1 interrupt request generates a signal, single-chip microcomputer in response to external interrupt request, the implementation of the external interrupt service subroutine, read the time difference, calculating the distance . Some of its source code is as follows:RECEIVE0: PUSH PSWPUSH ACCCLR EX0; related external interrupt 0MOV R7, TH0; read the time valueMOV R6, TL0?CLR CMOV A, R6SUBB A, # 0BBH; calculate the time difference MOV 31H, A; storage resultsMOV A, R7SUBB A, # 3CHMOV 30H, ASETB EX0; open external interrupt 0POP ACC?POP PSWRETI③, the ultrasonic ranging system software designSoftware is divided into two parts, the main program and interrupt service routine, shown in Figure 3 (a) (b) (c) below. Completion of the work of the main program is initialized, each sequence of ultrasonic transmitting and receiving control.Interrupt service routines from time to time to complete three of the rotation direction of ultrasonic launch, the main external interrupt service subroutine to read the value of completion time, distance calculation, the results of the output and so on.④. CONCLUSIONSRequired measuring range of 30cm ~ 200cm objects inside the plane to do a number of measurements found that the maximum error is 0.5cm, and good reproducibility. Single-chip design can be seen on the ultrasonic ranging system has a hardware structure is simple, reliable, small features such as measurement error. Therefore, it can be used not only for mobile robot can be used in other detection systems.Thoughts: As for why the receiver do not have the transistor amplifier circuit, because the magnification well, CX20106 integrated amplifier, but also with automatic gain control level, magnification to 76dB, the center frequency is 38k to 40k, is exactly resonant ultrasonic sensors frequencyAn integrated circuit is a small electronic device made out of a semiconductor material. The first integrated circuit was development in the 1950s by jack KILLBY of Texas instruments and Robert NOYCE of Fairchild semiconductor.Care must be taken when connecting logic circuits to ensure that their logic levels and current ratings are compatible. The output voltages produced by a logic circuit are normally specified in terms of worst case values when sourcing or sinking the maximum rated currents. Thus Vo is the guaranteed minimum “high” voltage when sourcing the maximum rated “high” output current I, while is the guaranteed minimum “low” output voltage when sink ing the maximum rated “low” output current Io. There are corresponding specification for logic inputs which specify the minimum input voltage which will be recognized as a logic “high” state Vi, and the maximum input voltage which will be regarded as a log ic “low” state Vil.For input interface, perhaps the main problem facing the designer is that of electrical noise. Small noises signals may cause the system to malfunction, while larger amounts of noise can permanently damage it. The designer must be aware of these dangers from the outset. There are many methods to protect interface circuits and microcomputer from various kinds of noise. Following are some example:总结与展望1. Input and output electrical isolation between the microcomputer system and external devices using a isolator or a transformer.2. Removing high frequency noise pulses by a low-pass filter and Schmitt-trigger.3. Protecting against excessive input voltages using a pair of diodes to power supply reversibly biased in normal direction.For output interface, parameters of a logic device are usually much to low to allow loads to be connected directly, and in practice an external circuit must be connected to amplify the current and voltage to drive a load. Although several types of semiconductor devices are now available for controlling DC and AC powers up to many kilowatts, there are two basic ways in which a switch can be connected to a load to control it.With series connection, the switch allows current to flow through the load when closed, while with shunt connection closing the switch allows current to bypass the load. Both connections are useful in low-power circuits, but only the series connection can be used in high-power circuits because of the power wasted in the series resistor R..AT89C52Compatible with MCS-51™ Products8K Bytes of In-System Reprogrammable Flash MemoryEndurance: 1,000 Write/Erase CyclesFully Static Operation: 0 Hz to 24 MHzThree-level Program Memory Lock256 x 8-bit Internal RAM32 Programmable I/O LinesThree 16-bit Timer/CountersEight Interrupt SourcesProgrammable Serial ChannelLow-power Idle and Power-down ModesDescriptionThe AT89C52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full-duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89C52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next hardware reset.AT89C52 Timer 2Timer 2 is a 16-bit Timer/Counter that can operate as either a timer or an event counter. The type of operation is selected by bit C/T2 in the SFR T2CON (shown in Table 2). Timer 2 has three operating modes: capture,auto-reload (up or down counting), and baud rate generator. The modes are selected by bits in T2CON, as shown in Table 3. Timer 2 consists of two 8-bit registers, TH2 and TL2. In the Timer function, the TL2 register is incremented every machine cycle. Since a machine cycle consists of 12 oscillator periods, the count rate is 1/12 of the oscillator frequency. In the Counter function, the register is incremented in response to a 1-to-0 transition at its corresponding external input pin, T2. In this function, the external input is sampled during S5P2 of every machine cycle. When the samples show a high in one cycle and a low in the next cycle, the count is incremented. The new count value appears in the register during S3P1 of the cycle following the one in which the transition was detected. Since two machine cycles (24 oscillator periods) are required to recognize a 1-to-0 transition, the maximum count rate is 1/24 of the oscillator frequency. To ensure that a given level is sampled at least once before it changes, the level should be held for at least one full machine cycle.With the rapid development of science and technology, the ultrasonic range finder in the more and more wide application. But the current technical level, people can use the specific range finder technology extremely limited, therefore, this is a booming and infinite prospect of technical and industrial areas. Looking to the future, ultrasonic range finder as a new type of very important and useful tool in a respect to have very big development space, it will move towards a more high-precision positioning in the direction of development, to meet the growing needs of the society, such as sonar basic trend for development: more suitable for operation in the shallow water of submarine sonar, especially in shallow sea target recognition problem to lower the submarine self noise, improve the working environment.Admit of no doubt, the future of the ultrasonic range finder with automation and intelligent community, and other rangefinders fusion, forming a rangefinder. As the range finder technology progress, ranging from simple judgment has the functions to the development has the learning function, the ultimate development of creativity. With the development of science and technology, the improvement of people's living standard, accelerate the development of city construction, city water supply and drainage system have greatly developed, the situation continues to improve. However, due to historical reasons the synthesis time lived many unpredictable factors, city water supply and drainage systems, especially the drainage system often lags behind the city construction. Therefore, often appear good building excavation has been building facilities to upgrade the drainage system phenomenon. Therefore, design and development of box culvert drainage dredging mobile robot automatic control system, to ensure the robot in the box culvert in free drainage dredging. Control system core part is the research and design of ultrasonic range finder.总结与展望In the new century, a new look of the range finder will play a better role.中文翻译电子技术历史毫无疑问的，20世纪是电子技术的世纪。