PROJECT REPORT

Industrial Conveyors Belt Counting Object System

INTRODUCTION:

Industrial conveyors belt counting object System, the aim of the project is to count number of object passed through conveyors belt automatically. Its save man-power and time. In this project we are using LDR and LASER as a sensors, controller, LCD display and DC motor.

However, in this project work on the basic principle of LDR and LASER. For count number of objects, LDR and LASER are used and according to there output objects count. The control circuit is designed using micro-controller. The outputs of count value compare with operational amplifier and are fed to micro-controller. The output of the micro-controller is used to drive the LCD display, so that the number of objects can be displayed.

BLOCK DIAGRAM:

DISPLAY

COMPUTER

AMP MICRCONTROLLERLDR

MAX232

LASER

MOTOR DRIVER

MEMORY

MOTOR

POWER SUPPLY

BLOCK DIAGRAM DESCRIPTION:

Micro-controller board: It is a low power, high-performance CMOS 8-bit microcomputer with 8K bytes of Flash Programmable and Erasable Read Only Memory ROM). The device is manufactured using Atmels high-density nonvolatile memory technology and is compatible with the MCS-51. Instruction set and pin out. The on chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, it provides a highly flexible and cost effective solution so many embedded control applications.

Memory Block: Memory stored number of objects which on conveyors belt.

Display Block: LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of applications. A 16x2 LCD display is very basic module and very commonly used in various devices and circuits. These modules are preferred over seven segments.

MAX Block: Max used for serial communication. As object counting stored in memory that data can downloaded through max 232.

LASER: When any object move on conveyors belt then laser give information to LDR that connected with operational amplifier. LDR: LDR or light dependence resistor is very useful especially in light/dark sensor. The lasers output given to LDR.

Motor Driver: L293D is a dual H-bridge motor driver, so with one IC we can interface two motors that can interface two DC motors that can be controlled in both clockwise and counter clockwise direction and fix direction of motion.

Power Block:For our project we require + 5 Volt, and +12 Volts supply. +5 Volts and. 5Volts is given to Micro-controller board, memory, max232etc. +12 Volts are used for motor driver IC to drive motor.COMPONENT DESCRIPTION:

POWER SUPPLY:

Power supply block consists of following units:

Step down transformer. Bridge rectifier circuit. Input filter. Voltage regulators. Output filter. Indicator unit.

Step down transformer:

The step-down transformer is used to step down the supply voltage of 230v ac from mains to lower values, as the various ICs used in this project require reduced voltages. The transformer consists of primary and secondary coils. To reduce or step down the voltage, the transformer is designed to contain less number of turns in its secondary core. The outputs from the secondary coil which is center tapped are the ac values of 0v, 15v and 15v. The conversion of these ac values to dc values to dc values is done using the full wave rectifier unit.

Rectifier Unit:

A diode bridge is an arrangement of four diodes connected in a bridge circuit. That provides the polarity of output voltage of any polarity of the input voltage. When used in its most common application, for conversion of alternating current (A.C) input into direct current (D.C) output, it is known as a bridge rectifier. The diagram describes a diode-bridge design known as a full wave rectifier. This design can be used to rectify single phase A.C. when no transformer center tap is available. A bridge rectifier makes use of four diodes in a bridge arrangement to achieve full wave rectification. This is a Widely used configuration, both with individual diodes wired as shown and with single component bridges where the diode bridge is wired internally.

For both positive and negative swings of the transformer, there is a forward path through the diode bridge. Both conduction paths cause current to flow in the same direction through the load resister, accomplishing full-wave rectification. While one set of diodes is forward biased, the other set is reverse biased and effectively eliminated from the circuit.

Input Filter:

Capacitors are used as filters.The ripples from the dc voltages are removed and pure dc voltage is obtained. The primary action performed by capacitor is charging and discharging. It charges in positive half cycle of the ac voltage and it will discharge in negative half cycle. So it allows only ac voltage and does not allow the dc voltage. This filter is fixed before the regulator.Capacitors used here are of the value 1000uF

Regulator unit:

Regulator regulates the output voltage to a specific value. The output voltage is maintained irrespective of the fluctuations in the input dc voltage. Whenever there are any ac voltage fluctuations, the dc voltage also changes, and to avoid this regulators are used.

Regulators can be classified as: Positive regulator, which regulates the positive voltage(7805,7812)

> input pin> ground pin> output pin

Negative regulator, which regulates the negative voltage (7912)

> ground pin> input pin> output pin

Regulators used in this application are: 7805 which provides 5v dc

Out put Filter:

This filter is fixed after the Regulator circuit to filter any of the possibly found ripples in the output received finally. Capacitors used here are of value 10F.

AT89S52 MICROCONTROLLER

The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory. The device is manufactured using Atmels high-density nonvolatile memory technology and is compatible with the industry- standard 80C51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer.

By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications.

The AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, 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 AT89S52 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 interrupt or hardware reset.

EEPROM MEMORY:

EEPROM(also writtenE2PROMand pronounced "e-e-prom," "double-e prom," "e-squared," or simply "e-prom") stands forElectricallyErasableProgrammableRead-OnlyMemory and is a type ofnon-volatile memoryused in computers and other electronic devices to store small amounts of data that must be saved when power is removed, e.g., calibration tables or device configuration.

When larger amounts of static data are to be stored (such as inUSB flash drives) a specific type of EEPROM such asflash memoryis more economical than traditional EEPROM devices. EEPROMs are realized as arrays offloating-gate transistors.

EEPROM is user-modifiable read-only memory (ROM) that can be erased and reprogrammed (written to) repeatedly through the application of higher than normal electrical voltage generated externally or internally in the case of modern EEPROMs. EPROM usually must be removed from the device for erasing and programming, whereas EEPROMs can be programmed and erased in circuit. Originally, EEPROMs were limited to single byte operations which made them slower, but modern EEPROMs allow multi-byte page operations. It also has a limited life - that is, the number of times it could be reprogrammed was limited to tens or hundreds of thousands of times. That limitation has been extended to a million write operations in modern EEPROMs. In an EEPROM that is frequently reprogrammed while the computer is in use, the life of the EEPROM can be an important design consideration. It is for this reason that EEPROMs were used for configuration information, rather than random access memory.

MAX 232Features:

Operates From a Single 5-V Power Supply With 1.0-_F Charge-Pump Capacitors Operates Up To 120 Kbit/s Two Drivers and Two Receivers 30-V Input Levels Low Supply Current . . . 8 mA Typical ESD Protection Exceeds JESD 22 2000-V Human-Body Model (A114-A)

Applications:

TIA/EIA-232-F, Battery-Powered Systems, Terminals, Modems, and Computers

Description:

The MAX232 is a dual driver/receiver that includes a capacitive voltage generator to supply TIA/EIA-232-F voltage levels from a single 5-V supply. Each receiver converts TIA/EIA-232-F inputs to 5-V TTL/CMOS levels. These receivers have a typical threshold of 1.3 V, a typical hysteresis of 0.5 V, and can accept 30-V inputs. Each driver converts TTL/CMOS input levels into TIA/EIA-232-F levels. The driver, receiver, and voltage-generator functions are available as cells.

The Serial Port

Incomputing, aserial portis aserial communicationphysical interface through which information transfers in or out onebitat a time (contrastparallel port).Throughout most of the history ofpersonal computers, data transfer through serial ports connected the computer to devices such asterminalsand various peripherals.

While such interfaces asEthernet,FireWire, andUSBall send data as a serialstream, the term "serial port" usually identifies hardware more or less compliant to theRS-232standard, intended to interface with amodemor with a similar communication device.

Modern computers without serial ports may require serial-to-USB converters to allow compatibility with RS 232 serial devices. Serial ports are still used in applications such as industrial automation systems, scientific instruments,shop tillsystems and some industrial and consumer products.Servercomputers may use a serial port as a control console for diagnostics. Network equipment (such as routers and switches) often use serial console for configuration. Serial ports are still used in these areas as they are simple, cheap and their console functions are highly standardized and widespread. A serial port requires very little supporting software from the host system.

LCD Display

The liquid-crystal display has the distinct advantage of having low power consumption than the LED. It is typically of the order of microwatts for the display in comparison to the some order of milli watts for LEDs. Low power consumption requirement has made it compatible with MOS integrated logic circuit. Its other advantages are its low cost, and good contrast.

The main principle behind liquid crystal molecules is that when an electric current is applied to them, they tend to untwist. This causes a change in the light angle passing through them. This causes a change in the angle of the top polarizing filter with respect to it. So little light is allowed to pass through that particular area of LCD. Thus, that area becomes darker comparing to others.

For making an LCD screen, a reflective mirror has to be setup in the back. An electrode plane made of indium-tin oxide is kept on top and a glass with a polarizing film is also added on the bottom side. The entire area of the LCD has to be covered by a common electrode and above it should be the liquid crystal substance. Next comes another piece of glass with an electrode in the shape of the rectangle on the bottom and, on top, another polarizing film. It must be noted that both of them are kept at right angles. When there is no current, the light passes through the front of the LCD it will be reflected by the mirror and bounced back. As the electrode is connected to a temporary battery, the current from it will cause the liquid crystals between the common-plane electrode and the electrode shaped like a rectangle to untwist. Thus the light is blocked from passing through. Thus, that particular rectangular area appears blank.

One of the main disadvantages of these types of LCDs is the size. Most manufacturers try to reduce the height than gain it. This is because more transistors and greater pixels will be needed to increase the length. This will increase the probability of bad pixels. It is very difficult or also impossible to repair a LCD with bad pixels. This will highly affect the sale of LCDs.LDR:

LDRs or Light Dependent Resistors are very useful especially in light/dark sensor circuits. These help in automatically switching ON /OFF the street lights and etc., normally the resistance of an LDR is very high, sometimes as very high as 1000000 ohms, but when they are illuminated with light, resistance drop dramatically. Electronic opto sensors are the devices that alter their electrical characteristics, in the presence of visible or invisible light. The best-known devices of these types are the light dependent resistor (LDR), the photo diode and the phototransistors.

LASER:

A laser diode is an electrically pumped semiconductor laser in which the active medium is formed by a p-n junction of a semiconductor diode similar to that found in a light-emitting diode. The laser diode is distinct from the optically pumped semiconductor laser, in which, while also semiconductor based, the medium is pumped by a light beam rather than electric current.

LM 358 OP-AMP:

The LM158 series consists of two independent, high gain, internally frequency compensated operational amplifiers which were designed specifically to operate from a single power supply over a wide range of voltages. Operation from split power supplies is also possible and the low power supply current drain is independent of the magnitude of the power supply voltage. Application areas include transducer amplifiers, dc gain blocks and all the conventional op amp circuits which now can be more easily implemented in single power supply systems. For example, the LM158 series can be directly operated off of the standard +5V power supply voltage which is used in digital systems and will easily provide the required interface electronics without requiring the additional 15V power supplies. The LM358 and LM2904 are available in a chip sized package (8-Bump micro SMD) using Nationals micro SMD package technology.

Unique Characteristics In the linear mode the input common-mode voltage range includes ground and the output voltage can also swing to ground, even though operated from only a single power supply voltage. The unity gain cross frequency is temperature compensated. The input bias current is also temperature compensated.

MOTOR DRIVER:

Features:

600ma output current capability per channel 1.2a peak output current (non repetitive) per channel Enable facility Over temperature protection Logical "0" input voltage up to 1.5 v (high noise immunity) Internal clamp diodes

General Description:

The device is a monolithic integrated high voltage, High current four channel driver designed to Accept standard dtl or ttl logic levels and drive Inductive loads (such as relays solenoids, dc And stepping motors) and switching power transistors. To simplify use as two bridges each pair of channels is equipped with an enable input. A separate Supply input is provided for the logic, allowing operation at a lower voltage and internal clamp diodes are included. This device is suitable for use in switching applications at frequencies up to 5 kHz. The l293d is assembled in a 16 lead plastic Package which has 4 center pins connected together and used for heat sinking the l293dd is assembled in a 20 lead surface Mount which has 8 center pins connected together And used for heat sinking.

WORKING:

Indusrtial conveyors belt counting object system can be used in industries where reqirement of counting number of objects. All these can be done by control circuit LDR and LASER sensor. It reduce man power and within a short span of time it counts objects.

As motor starts, conveyors belt start rolling. Objects are placed on it, as object shifted on conveyors belt. LASER fall on LDR if there is any object it detect and then LDR give output to op-amp. This output compared by op-amp and then apply to microcontroller. Microcontroller display number of objects on LCD and these process continue. There is also memory that stored number of objects so that we can download thses counting value any time by using serial port.

- 2 -