ERADIS – Electronic

Ration Distribution

System

This Machine is invented

by:-

Umang Sharma

(Group Leader)

Vaibhav Kumar

Vikalp Chauhan

This section includes-

Embedded Systems

ERADIS-Electronic Ration

Distribution System.

Pictorial View of ERADIS

System Design

Flow Chart

Working

INTRODUCTION

Introduction

Embedded systems:

An embedded system is a computer system designed to do one or a

few dedicated and/or specific functions often with real-time

computing constraints. It is embedded as part of a complete device often

including hardware and mechanical parts. By contrast, a general-purpose

computer, such as a personal computer (PC), is designed to be flexible and to

meet a wide range of end-user needs. Embedded systems control many

devices in common use today.

Embedded systems are controlled by one or more main processing cores that

are typically either microcontrollers or digital signal processors (DSP). The

key characteristic, however, is being dedicated to handle a particular task.

They may require very powerful processors and extensive communication,

for example air traffic control systems may usefully be viewed as embedded,

even though they involve mainframe computers and dedicated regional and

national networks between airports and radar sites (each radar probably

includes one or more embedded systems of its own).

Since the embedded system is dedicated to specific tasks, design engineers

can optimize it to reduce the size and cost of the product and increase the

reliability and performance. Some embedded systems are mass-produced,

benefiting from economies of scale.

Physically, embedded systems range from portable devices such as digital

watches and MP3 players, to large stationary installations like traffic

lights, factory controllers, or the systems controlling nuclear power plants.

Complexity varies from low, with a single microcontroller chip, to very high

with multiple units, peripherals and networks mounted inside a

large chassis or enclosure.

In general, "embedded system" is not a strictly definable term, as most

systems have some element of extensibility or programmability. For

example, handheld computers share some elements with embedded systems

such as the operating systems and microprocessors that power them, but they

allow different applications to be loaded and peripherals to be connected.

Moreover, even systems that do not expose programmability as a primary

feature generally need to support software updates. On a continuum from

"general purpose" to "embedded", large application systems will have

subcomponents at most points even if the system as a whole is "designed to

perform one or a few dedicated functions", and is thus appropriate to call

"embedded".

Figure1: Block Diagram of an Embedded System Showing Different Software & Hardware Components.

Looking onto the above block diagram one can easily observe that what all an

embedded system constitutes of.

Our project – Electronic RAtion DIstribution System (ERADIS) is also

an Embedded System since it includes a perfect share of hardware and

an appreciable share of software as well.

ERADIS Like in many of the embedded systems consists of Program

source code, a microcontroller, a circuit with which the microcontroller

is interfaced (Weighing machine), a keypad and other keys as user

interface, a display, power supply and other supporting electronic

circuitry.

The actual concept of ERADIS is explained in detail further.

Electronic RAtion DIstribution System (ERADIS)

“Electronic Ration Distribution System(ERADIS)”- The name speaks for itself, is an important, innovative, and a totally new concept thought by our group taking into account the various social, economic and general aspects relating to technical as well as day to day disciplines.

“Electronic Ration Distribution System(ERADIS)”- means distribution of essential commodities to a large number of people through a network on a recurring basis in an automated way.

The Concept is to automate the Public Distribution System (PDS), A Govt. Of India initiative Process in which a fixed amount of ration is provided monthly to the people by the PDS stores.

Our group thought of this concept because the increased corruption in the market sector can be prevented if system becomes automated, increased adulteration can be prevented as well, the hoarding done by the officials and labourers of Govt. Super Bazaars (PDS Stores) which in turn leads to price hike can be prevented using this system.

The apparatus we are designing is cost effective and can prove helpful to Govt. Of India’s PDS System and to various other disciplines. In terms of feasibility it is a vast concept and an interesting task to perform and totally feasible in all aspects technical as well as other.

Advantages of employing ERADIS are:

increased corruption in the Govt. As well as market sector can be prevented if system becomes automated

increased adulteration in consumables can be prevented the problem of hoarding at Govt. Super Bazaars (PDS Stores) that gives

rise to price hike can be prevented cost effective approach time saving approach

Pictorial View of ERADIS

Figure2: Pictorial view of ERADIS

The detailed description of ERADIS is given in further sections.

System Design

Figure3: Front View of ERADIS.

Figure4: Side View of ERADIS.

Flow Chart

Start

Check Reading on weighing machine

Is Reading

Zero?

Press

ZERO Key

No

Yes

Press SET key to store the value

entered by the user

Enter the desired value

Solenoid opens the flap of the container to release the items

Items start to collect on container kept on Weighing Machine

Weighing Machine checks the value

Is Weighing Machine

Reading Equal to the

value entered

(Desired Value)?

Solenoid closes the flap of the container

No

Yes

Stop

Working

Looking on to the system designs above one can easily predict the working of ERADIS- “Electronic Ration Distribution System”. In this system there is a container in which the items (wheat, rice etc.) are stored. A user enters the required amount using a Keypad, whenever a key is pressed the buzzer indicates that a key has been pressed by buzzing, the moment user enters a value the solenoid releases the flap and the items are collected in a container which is placed on a weighing machine, and when the load on weighing machine equals the value entered by the user the solenoid again pushes the flap back towards the container. Spring is used to keep the flap closed when the power is off. Also there is a provision of SET and ZERO key which is used to enter a value and to make the reading of the weighing machine zero respectively. The power supply used here is 12 Volts Battery for microcontroller and A.C. Supply for solenoid. A wooden table is used to showcase the system properly and to demonstrate the intended functions. The electronics part of the project is aligned systematically in a plastic box so as to ensure that the connections remain intact.

Snapshot of ERADIS’s working is given as follows:

1. Setting the value to zero using ZERO Key and storing the entered value

using SET Key:-

Figure5: Snapshot 1 of ERADIS.

2. Entering the value using Keypad:-

Figure6: Snapshot 2 of ERADIS.

3. As soon as the user enters a value the solenoid opens the flap of the

container and the item (wheat) start falling on the collecting tray placed

on weighing machine:-

Figure7: Snapshot 3 of ERADIS.

4. Display showing the amount which has been received in the collecting

tray placed on the weighing machine:-

Figure8: Snapshot 4 of ERADIS.

5. Item released by the container getting collected in collecting tray:-

Figure9: Snapshot 5 of ERADIS.

6. When the reading of weighing machine equals the entered value

(Desired Value) the Solenoid closes the flap of the container and

restricts the item from falling on collecting tray:-

Figure10: Snapshot 6 of ERADIS.

Block Diagram

The Block diagram of ERADIS depicting the important components is shown

below:

Figure11: Block Diagram of ERADIS

Hence the ERADIS consists of following parts:

Container

Weighing Machine

Solenoid & Spring Arrangement

User Interface

Display

Power Supply

Control Unit

Container

Weighing

Machine

Solenoid &

Spring

Arrangement

Control

Unit

User Interface

Keypad

SET and

ZERO

Key

Display

Power Supply

Container

The container used in the project is the one used to store mustard oil. The

further changes in the orientation of the container as per requirements are

explained as below:

This is how the container was adapted to use in ERADIS.

Figure12: Step1: A mustard Oil

Container was taken

Figure13: Step2: The Container

was chopped off from the top

Figure14: Step3: A small

rectangular hole was done at the

bottom of the container

Figure15: Step4: A flap was

placed on that rectangular hole

Weighing Machine

Figure16: Weighing Machine used in the project.

What is a Weighing Machine?

A weighing scale is a measuring instrument for determining the weight

or mass of an object. When you place an object on a digital weigh scale, the

load cell senses the weight and sends the signal to the indicator. The signal

conditioner processes the load cell signal and displays weight.

Design Considerations

Weigh scales have wide range of uses in industrial, commercial and consumer applications. Electronic weight scales design is based on using a load cell as the primary transducer. Load cell designs can be distinguished according to the type of output signal generated (pneumatic, hydraulic, electric). Strain-gage load cells convert the load acting on them into electrical signals with the output in range of mV/V. The signal chain has to handle the small signal accurately in presence of noise. The signal then has to be processed for non-linearity, temperature dependency and offset errors and drifts. Hence the signal chain consists of appropriate excitation technique, signal conditioning, signal acquisition and processing and interface and communication.

Excitation Technique:-

The sensor needs an accurate and a highly stable excitation source. Many pressure sensor designs use the same common reference for the excitation circuitry and the ADC for better accuracy and the thus the sensor output is ratio metric. Reference Voltages provide cost effective solution for the

mentioned requirements with high initial accuracy and extremely low temperature drift.

Signal Conditioning:-

In most Load cells the output range of a strain gauge is very small and thus

the signal needs to be amplified before processing to prevent introduction of

errors. Market provides a wide selection of Low Noise Amplifiers with high

CMRR and high gain at low frequencies suitable for the small signal output of

the sensor. Additionally, since the signal bandwidth is low, the 1/f noise of the

amplifiers can introduce errors. Chopper-stabilization amplifiers provide

extremely high dc precision and noise performance at low frequency range.

Highly efficient solutions tailored for Weigh Scale application comprise of

precise, low-drift programmable gain instrumentation amplifiers with high

common mode rejection ratio and proprietary auto-zero techniques.

Signal Acquisition and Processing:-

High resolution differential ADCs have low temperature and offset drifts

required for Weigh Scale application before it is sent to a MCU.

Microcontroller can be used to perform calibration and compensation in

addition to using the on-chip data converters for data acquisition. It also

provides functions including calculation and signal processing, friendly user

interface such as Seven Segment Display and key pad control.

Power Supply:-

The Weigh Scale can be Line Powered (AC Mains supply) or Battery Powered.

Compare a mechanical scale to an electronic scale. Mechanical scale just shows the weight but an electronic scale does much more than that- it helps to automate.

Load Cells

Figure17: Load Cell arrangement for weighing machine.

What is a “Load Cell”?

A load cell is a transducer that is used to convert a force into electrical signal.

This conversion is indirect and happens in two stages. Through a mechanical

arrangement, the force being sensed deforms a strain gauge. The strain gauge

measures the deformation (strain) as an electrical signal, because the strain

changes the effective electrical resistance of the wire. A load cell usually

consists of four strain gauges in a Wheatstone bridge configuration. Load cells

of one strain gauge (quarter bridge) or two strain gauges (half bridge) are

also available. The electrical signal output is typically in the order of a few

millivolts and requires amplification by an instrumentation amplifier before it

can be used. The output of the transducer is plugged into an algorithm to

calculate the force applied to the transducer.

Figure18: Quarter Bridge Circuit for Strain Guage

Solenoid & Spring Arrangement

Figure19: A.C. Solenoid with pressure bearing capacity of 1kg

What is a “Solenoid”?

A solenoid is a coil wound into a tightly packed helix. In physics, the

term solenoid refers to a long, thin loop of wire, often wrapped around

a metallic core, which produces a magnetic field when an electric current is

passed through it. Solenoids are important because they can create controlled

magnetic fields and can be used as electromagnets. The term solenoid refers

specifically to a magnet designed to produce a uniform magnetic field in a

volume of space (where some experiment might be carried out). The term is

also often used to refer to a solenoid valve, which is an integrated device

containing an electromechanical solenoid which actuates either

a pneumatic or hydraulic valve, or a solenoid switch, which is a specific type

of relay that internally uses an electromechanical solenoid to operate an

electrical switch; for example, an automobile starter solenoid, or a linear

solenoid, which is an electromechanical solenoid.

Figure20: Working Principle of Solenoid

Figure21: Spring of Diameter 1 Inches (Approximately)

What is a “Spring”?

A spring is an elastic object used to store mechanical energy. Springs are

usually made out of hardened steel. Small springs can be wound from pre-

hardened stock, while larger ones are made from annealed steel and

hardened after fabrication. Some non-ferrous metals are also used

including phosphor bronze and titanium for parts requiring corrosion

resistance and beryllium copper for springs carrying electrical current

(because of its low electrical resistance).

When a spring is compressed or stretched, the force it exerts is proportional

to its change in length. The rate or spring constant of a spring is the change in

the force it exerts, divided by the change in deflection of the spring. That is, it

is the gradient of the force versus deflection curve.

Depending on the design and required operating environment, any material

can be used to construct a spring, so long as the material has the required

combination of rigidity and elasticity: technically, a wooden bow is a form of

spring.

In ERADIS Spring is used to keep the flap closed when the power is off.

Solenoid is used to stop and allow the flow the flow of items from the

container.

Keypad

Ep

pe

c 5

13

1

Figure22: PCB Layout of 4x4 Keypad

What is a “Keypad”?

A keypad is a set of buttons arranged in a block or "pad" which usually bear

digits, symbols and usually a complete set of alphabetical letters. If it mostly

contains numbers then it can also be called a numeric keypad. Keypads are

found on many alphanumeric keyboards and on other devices such as

calculators, push-button telephones, combination locks, and digital door

locks, which require mainly numeric input.

Figure23: A4x4 Keypad

SET & ZERO Keys

These keys are the important part of the user interface as they are used for

setting the value entered by the user and to set the value to zero respectively.

ZERO: This key is used when the reading of the weighing machine is not

equal to zero when no weight is placed on it.

This key when pressed, sets the reading to zero.

SET: This key is used when user wants to enter a value.

This key when pressed, jumps the program execution to Keypad so as to

get an input from the user. This is terminated when ENTER is pressed

on the keypad.

Figure24: SET & ZERO Keys (part of User Interface)

In ERADIS the SET & ZERO keys are the important part of the user

interface as it is basically used to activate the keypad.

Buzzer

Figure25: Picure of the Buzzer used in ERADIS

What is a Buzzer?

A buzzer or beeper is an audio signaling device, which may

be mechanical, electromechanical, or Piezoelectric. Typical uses of buzzers

and beepers include alarms, timers and confirmation of user input such as a

mouse click or keystroke. The circuit Diagram of the buzzer used in ERADIS is

given as follows.

Figure26: Circuit Diagram of the Buzzer used in ERADIS

In ERADIS a Buzzer is just used to indicate that a key has been pressed

on Keypad.

Functional Numeric Display (FND) ( 7 - Segment Display)

Figure27: PCB Layout of Common Negative (-) FND Display

What is a “Seven Segment Display”?

A seven-segment display, or seven-segment indicator, is a form of

electronic display device for displaying decimal numerals that is an

alternative to the more complex dot-matrix displays. Seven-segment displays

are widely used in digital clocks, electronic meters, and other electronic

devices for displaying numerical information. A seven segment display, as its

name indicates, is composed of seven elements. Individually on or off, they

can be combined to produce simplified representations of the arabic

numerals. Often the seven segments are arranged in an oblique (slanted)

arrangement, which aids readability.

Figure28: Seven Segment Display showing individual elements (LED’s)

Power Supply

12 Volts Battery (For Microcontroller Circuit)

Figure29: 12 Volt Battery

What is a 12 V lead acid Battery?

Structure and Operation: Most lead-acid batteries are constructed with the positive electrode (the anode) made from a lead antimony alloy with lead (IV) oxide pressed into it, although batteries designed for maximum life use a lead-calcium alloy. The negative electrode (the cathode) is made from pure lead and both electrodes are immersed in sulphuric acid. When the battery is discharged water is produced, diluting the acid and reducing its specific gravity. On charging sulphuric acid is produced and the specific gravity of the electrolyte increases.

A.C. Supply( For A.C. Solenoid)

An AC power supply typically takes the voltage from a wall outlet (mains

supply, often 220v-230v) and lowers it to the desired voltage (e.g. 9vac). As

well as lowering the voltage some filtering may take place.

The components used are discussed in further section.

Power Supply: Components Used

Te component used in the power supply of ERADIS are as follows:

1. IC7805: This is an IC of a Voltage Regulator (+5V Output). It is a member of 78xx series of fixed linear voltage regulator ICs. The voltage source in a circuit may have fluctuations and would not give the fixed voltage output. The voltage regulator IC maintains the output voltage at a constant value. The xx in 78xx indicates the fixed output voltage it is designed to provide. 7805 provides +5V regulated power supply. Capacitors of suitable values can be connected at input and output pins depending upon the respective voltage levels. Pin Configuration is given as follows-

Figure30: Pin Configuration of IC-7805

Pin Description:

Figure31: Pin Description of IC-7805

2. IC-7905: This is an IC of a Voltage Regulator(-5V Output). It is a member of 79xx series of fixed linear voltage regulator ICs. The voltage source in a circuit may have fluctuations and would not give the fixed voltage output. The voltage regulator IC maintains the output voltage at a constant value. The xx in 78xx indicates the fixed output voltage it is designed to provide. 7905 provides a regulated supply of -5 V and 1A current. Its additional features include internal thermal overload protection, short circuit protection and output transistor safe operating area compensation. Pin Configuration is given as follows-

Figure32: Pin Configuration of IC-7905

Pin Description:

Figure33: Pin Description of IC-7905

3. ICL-7660: This is an IC of a Voltage Converter. This is used for

Simple Conversion of +5V Logic Supply to ±5V Supplies. Pin

Configuration is given as follows-

Figure34: Pin Configuration of ICL-7660

Pin Description:

N.C.(ICL7660): No Connection

CAP+: Connection to positive terminal of Charge-Pump

Capacitor.

GND Ground: For most applications, the positive terminal of

the reservoir capacitor is connected to this pin.

CAP-: Connection to negative terminal of Charge-Pump

Capacitor.

VOUT Negative Voltage Output: For most applications, the

negative terminal of the reservoir capacitor is connected to

this pin.

LV Low-Voltage Operation: Connect to ground for supply

voltages below 3.5V. ICL7660: Leave open for supply voltages

above 5V.

OSC Oscillator Control Input: Connecting an external capacitor

reduces the oscillator frequency. Minimize stray capacitance at

this pin.

V+ Power-Supply Positive Voltage Input: (1.5V to 10V). V+ is

also the substrate connection.

4. 12 Volt Relay (used to Energize the Solenoid Coil):

A relay is an electrically operated switch that isolates one electrical circuit from another. In its simplest form, a relay consists of a coil used as an electromagnet to open and close switch contacts. Since the two circuits are isolated, a lower voltage circuit can be used to trip a relay, which will control a separate circuit that requires a higher voltage or amperage. A 12-volt relay requires 12 volts direct current (DC) to energize the coil. Relays can be found in early telephone exchange equipment, in industrial control circuits, as a starter solenoid in automobiles, on water pumps, in high-power audio amplifiers, and as protection devices. Below is the schematic of a 12 Volt, 5-Pin, Single Contact, D.C. Relay.

Figure35: Pin Configuration of a 12 Volt Relay

Pin Description:

N/O: Normally Open N/C: Normally Closed COMMON: Common Connection COIL: A.C. Supply to the Coil

Control Unit

Control Unit is the actual intelligence of ERADIS since it constitutes of the

most significant components used in any embedded system eg.

Microcontroller, circuit board, programming (application) etc. The control

unit is responsible for accomplishing the desired operation i.e. it is solely

responsible for automation of the system. The supporting technology behind

control unit is embedded systems.

Hence it is obvious to divide control unit into two parts as follows:

Hardware Platform:

Weighing Machine Circuit

Power Supply Circuits

Microcontroller AT89S52 & other IC’s

Topwin Program Burner Hardware

Software:

UMPS Compiler (To program microcontroller AT89S52 )

Topwin Program Burner Software

CORELDRAW (To design the PCB’s used in ERADIS)

Additional Hardware:

A plastic box to accommodate all the electronic circuitry so as to avoid

the intermittency in connection as when the circuit will be packed the

connections will remain intact.

A wooden table to demonstrate the desired working.

The detailed explaination of subcomponents of ERADIS is given in further

sections.

Weighing Machine PCB Layout

Figure36: PCB Layout of Weighing Machine ( Component Side)

Splder side

S-B

mic

ro w

eig

hin

g s

yste

m

Figure37: PCB Layout of Weighing Machine (Solder Side)

The efficient laying out of traces on a PCB is a complex skill, and requires

much patience. This task has been made vastly easier with the advent of

readily available PCB layout software, but it is still challenging.

The PCB Layouts given above are designed using a software named

CORELDRAW.

Component side

RWGB

Weighing Machine Circuit Diagram

Figure38: Circuit Diagram of Weighing Machine

Circuit Diagram Description

The above Circuit Diagram shows the part of our project which is its actual

intelligence. It shows clearly that the output of load cells (RWBG) is given to

Operational Amplifiers OP-07, then the amplified output from op-amps is

given to ADC’s IC-7135 which converts the analog input to digital output, ADC

is used because a Microcontroller understands digital signals, Also in the

above diagram, there is an IC 7404 which is used as an inverting amplifier and

an IC 4050 which is a Non-Inverting Amplifier. In the circuit diagram above

there is an IC 74HC390 which is used here as clock divider for the ADC-MCU

interface. The Microcontroller used is AT89S52. The Hex to Decimal

conversion is done by the Decoder IC-74HC138, this is done to display the

output on Display Segment. The display segment consists of Common

Negative Seven Segment Display (FND). There is also a ULN Driver.

IC’s which are used in the Circuit are as follows:

OP-07

IC-7135

IC-7404

IC-4050

IC-74HC390

IC-AT89S52

IC-ULN2003

IC-74HC138

These IC’s are explained in detail in further sections.

Weighing Machine Circuit – Components Used

1. OP-07: This is an IC of an Operational Amplifier. Pin Configuration is

given as follows-

Figure39: Pin Configuration of OP-07

Pin Description:

VOS TRIM: Input offset voltage.

-IN: Inverting Input

+IN: Non-Inverting Input

V-,V+: IC’s Power Supply pins.

OUT: Output of the Operational Amplifier.

NC: No Connection

2. IC-7135: This is an IC of an ADC (Analog to Digital Converter). Pin

Configuration is given as follows-

Figure40: Pin Configuration of IC-7135

Pin Description:

V+,V-: IC’s Power Supply Pins

AZ: Auto Zero

INT: Signal Integrate

IN HI, IN LO: Internal Input High & Low

ANALOG COMMON: It is used as the input low return during auto-

zero and de-integrate.

REFERENCE: The reference input must be generated as a positive

voltage with respect to COMMON.

Run/HOLD: When high (or open) the A/D will free-run with

equally spaced measurement cycles every 40,002 clock pulses. If

taken low, the converter will continue the full measurement cycle

that it is doing and then hold this reading as long as R/H is held

low.

STROBE: This is a negative going output pulse that aids in

transferring the BCD data to external latches, UARTs, or

microprocessors.

BUSY: This pin goes high at the beginning of signal integrate and

stays high until the first clock pulse after zero crossing (or after

end of measurement in the case of an overrange).

OVERRANGE: This pin goes positive when the input signal

exceeds the range (20,000) of the converter.

UNDERRANGE: This pin goes positive when the reading is 9% of

range or less.

POLARlTY: This pin is positive for a positive input signal. It is

valid even for a zero reading.

DIGIT DRIVES (Pins 12, 17, 18, 19 and 20): Each digit drive is a

positive going signal that lasts for 200 clock pulses. The scan

sequence is D5 (MSD), D4, D3, D2, and D1 (LSD).

BCD (Pins 13, 14, 15 and 16): The Binary coded Decimal bits B8,

B4, B2, and B1 are positive logic signals that go on simultaneously

with the digit driver signal.

3. IC-7404: This is an IC of an Inverting Amplifier. Pin Configuration is

given as follows-

Figure41: Pin Configuration(Functional) of IC-7404

Functional Table:

Figure42: Functional Table of IC-7404

H: High Logic Level

L: Low Logic Level

VCC & GND: These pins are the IC’s Power Supply Pins.

4. IC-4050: This is an IC of a Non-Inverting Amplifier. Pin Configuration is

given as follows-

Figure43: Pin Configuration of IC-4050

Pin Description:

VDD: Supply voltage

1Y-6Y: Outputs

1A-6A: Inputs

VSS: Ground Supply Voltage

NC: Not Connected

5. IC-74HC390: This is an IC of a Dual Decade Ripple Counter. Pin

Configuration is given as follows-

Figure44: Pin Configuration of IC-74HC390

Pin Description:

1CP0, 2CP0: Clock input divide-by-2 section (HIGH-to-LOW, edge-

triggered)

1MR, 2MR: Asynchronous master reset inputs (active HIGH)

1Q0 to 1Q3: Flip-Flop outputs

1CP1, 2CP1: Clock input divide-by-5 section (HIGH-to-LOW, edge

triggered)

GND: Ground (0 V)

2Q0 to 2Q3: Flip-Flop outputs

VCC: Positive Supply Voltage

6. IC-AT89S52: This is an IC of a Microcontroller. Pin Configuration is

given as follows-

Figure45: Pin Configuration of IC-AT89S52

Pin Description:

Port0: Port 0 is an 8-bit open drain bidirectional I/O port. As an

output port, each pin can sink eight TTL inputs. When 1s are

written to port 0 pins, the pins can be used as high impedance

inputs.

Port1: Port 1 is an 8-bit bidirectional I/O port with internal pull

ups. The Port 1 output buffers can sink/source four TTL inputs.

Port Pin Alternate Functions:-

P1.0 T2 (external count input to Timer/Counter 2), clock-out

P1.1 T2EX (Timer/Counter 2 capture/reload trigger and direction

control)

P1.5 MOSI (used for In-System Programming)

P1.6 MISO (used for In-System Programming)

P1.7 SCK (used for In-System Programming

Port2: Port 2 is an 8-bit bidirectional I/O port with internal pull-

ups. The Port 2 output buffers can sink/source four TTL inputs.

Port3: Port 3 is an 8-bit bidirectional I/O port with internal

pullups. The Port 3 output buffers can sink/source four TTL

inputs.

Port Pin Alternate Functions:-

P3.0 RXD (serial input port) P3.1 TXD (serial output port) P3.2 INT0 (external interrupt 0) P3.3 INT1 (external interrupt 1) P3.4 T0 (timer 0 external input) P3.5 T1 (timer 1 external input) P3.6 WR (external data memory write strobe) P3.7 RD (external data memory read strobe)

RST: Reset Input

ALE/PROG: Address Latch Enable (ALE) is an output pulse for

latching the low byte of the address during accesses to external

memory. This pin is also the program pulse input (PROG) during

Flash programming.

PSEN: Program Store Enable (PSEN) is the read strobe to external

program memory.

EA/VPP: External Access Enable. EA must be strapped to GND in

order to enable the device to fetch code from external program

memory locations starting at 0000H up to FFFFH. This pin also

receives the 12-volt programming enable voltage (VPP) during

Flash programming.

XTAL1: Input to the inverting oscillator amplifier and input to the

internal clock operating circuit.

XTAL2: Output from the inverting oscillator amplifier.

7. IC-74HC138: This is an IC of a Decoder. Pin Configuration is given as

follows-

Figure46: Pin Configuration of IC-74HC138

Pin Description:

A0: Address Input 0

A1: Address Input 1

A2: Address Input 2

E1: Enable Input 1

E2: Enable Input 2

E3: Enable Input 3

Y7: Output 7

GND: Ground

Y6: Output 6

Y5: Output 5

Y4: Output 4

Y3: Output 3

Y2: Output 2

Y1: Output 1

Y0: Output 0

VCC: Positive Supply Voltage

8. ULN-2003: This is an IC used as a driver for Display Section i.e. FND

Display. Pin Configuration is given as follows-

Figure47: Pin Configuration of ULN-2003

Pin Description:

Pin No. 1 to 8: Input pins

Pin No. 11 to 18: Output Pins

Pin No. 9: GND (Ground)

Pin No. 10: Free Wheeling Diode Pins

The above description explained the hardware platform of ERADIS. The

further section includes the Software descriptions.

SOFTWARE SECTION

Screenshots Of CORELDRAW for designing the PCB’s used in ERADIS.

Figure48: Screenshot of CORELDRAW

Figure49: Screenshot of CORELDRAW

Screenshot of Universal Microprocessor Program Simulator (UMPS).

Figure50: Screenshot of UMPS

Code Description

The Program Source Code to be burned on Microcontroller AT89S52

constitutes following functions:

Function 1: To assign the location for FND channels

Function 2: For FND (Display)

Function 3: The main program of Weighing Scale.

Function 4: For setting the value of all channels of FND to Zero

Function 5: For checking the FND after restarting the program.

Function 6: For FND display

Function 7: For converting the Hexadecimal value into the Decimal

value

Function 8: For entering the value through keypad.

Function 9: For displaying and storing the values from 0 to 9

Function 10: For storing the value entered by the keypad

Function 11: For comparing the value of key store (entered value)

& scale reading

Hence as per requirements the program has been manipulated and has been

divided into separate functions so that it can be understood easily and also to

provide flexibility so that it can be manipulated further if required. The

program is written using the basic instruction set of the microcontroller used

and has been compiled using a software named Universal Microprocessor

Program Simulator (UMPS) and has been burned to the microcontroller using

a software named TOPWIN.

The complete program source code is given in further sections.

The source code explained is divided according to the functions as declared

above and has been clearly specified. The code is written in assembly level

language using the instruction set of the microcontroller used.

The code is working correctly and has been properly debugged before

burning it to the microcontroller.

Program source code:

Function 1: To assign the location for FND channels

ch1 equ 70h ;assign 70-7ah for channels of FND

ch2 equ 72h

ch3 equ 74h

ch4 equ 76h

ch5 equ 78h

ch6 equ 7ah

org 00h ;p1.1 for busy *//// start the program from that location

mov sp,#0fh

mov 7eh,#00h ;zero

mov 7fh,#00h ;zero

freq:

sjmp fnd

org 0bh *////

ljmp disp

ljmp over

org 2bh *////

clr tr2

mov 32h,rcap2h

mov 33h,rcap2l

clr ie.5 ;dis int

reti

disp:

mov tl0,#0fbh ;display timer value low

mov th0,#0efh ;display timer value high

setb psw.3

mov p0,@r0

inc r0

mov p2,@r0

inc r0

cjne r0,#7ch,nxt

mov r0,#ch1

nxt:

clr psw.3 *//// start the 3rd

bit of the first register bank

reti

Function 2: For FND (Display)

fnd:

setb psw.3 *//// stop the register bit

mov r4,#00h

mov r0,#ch1

mov tl0,#0fbh

mov th0,#0efh

mov tmod,#01h

setb tcon.4

clr psw.3 *//// start the register bit

mov ch1,#00h

mov 71h,#00 *//// assign that address for the cathode of FND

mov ch2,#00h (71h,73h,75h,77h,79h,7bh)

mov 73h,#00

mov ch3,#00h

mov 75h,#00

mov ch4,#00h

mov 77h,#00

mov ch5,#00h

mov 79h,#00

mov ch6,#00h

mov 7bh,#00

mov 7ch,#00

setb psw.3

mov r0,#ch1

inc r0 *// increment the r0 to make that value as the anode of

fnd

mov @r0,#00h

inc r0

inc r0

mov @r0,#01h

inc r0

inc r0

mov @r0,#02h

inc r0

inc r0

mov @r0,#03h

inc r0

inc r0

mov @r0,#04h

inc r0

inc r0

mov @r0,#05h

mov r0,#ch1

clr psw.3

jnb p1.3,ram_zero1 ;ignore rom read

ljmp over1

ram_zero1:

mov 4ah,#00h ; ram add fill zero

mov 4bh,#00h

mov 4ch,#00h

mov 4dh,#00h

mov 4eh,#00h

mov 4fh,#00h

over1:

mov rcap2h,#00h

mov rcap2l,#00h

mov th2,#00h

mov tl2,#00h

mov t2con,#00h

mov t2mod,#02h

mov t2con,#0bh

mov ie,#0a2h

here1:

jnb p1.1,here1 ; busy

setb tr2 ; timer start

lcall subt

lcall rutin

lcall calcu

lcall bcd10.....

lcall delay1

lcall delay1

lcall delay1

lcall delay1

lcall delay1

ljmp over

Function 3: The main program of Weighing Scale.

*//// in this the subprograms are being called as per requirements

*//// in over: assigning the value of interrupts has been done

over:

mov rcap2h,#00h

mov rcap2l,#00h

mov th2,#00h

mov tl2,#00h

mov t2con,#00h

mov t2mod,#02h

mov t2con,#0bh

mov ie,#0a2h

*//// in ‘here’ jump not bit instruction is being used to use the interrupts

here:

jnb p1.1,here ;busy

setb tr2 ;timer start

lcall subt ; subtract 10000 adc count from adc capture.

jnb p1.2,zero ; zero present count

aee:

*//// in this we called the following instruction set

lcall rutin ; find out data '+'or '-' .

lcall calcu ; capture value hex convart from hex to decimal.

lcall transfar_to_bcd ; data transfer to bcd display add.

lcall bcd

lcall comp_value

; lcall delay1

; lcall delay1

; lcall delay1

jnb p1.5, key *//// after getting the p1.5 high, the execution jump to:

; lcall delay1

lcall delay1

ljmp over *//// otherwise again and again execution occured in

the over:

Function 4: For setting the value of all channels of FND to Zero

Key:

mov 61h,#0h ;most

mov 62h,#0h

mov 63h,#0h

mov 64h,#0h

mov 65h,#0h ;list

lcall bcd *//// show the all channels of FND 0.

ljmp key_board *//// when all channels is 0,

then execution goes to the keyboard program

Zero:

mov 7eh,32h ; high hex capture value save to another ram

mov 7fh,33h ; low hex capture value save to another ram

ljmp aee

Function 5: For checking the FND after restarting the program.

bcd1:

mov a,#09 ;after restart the program digit chake'9',

mov 61h,a ;at a time all six channels.

mov 62h,a

mov 63h,a

mov 64h,a

mov 65h,a

lcall bcd

lcall delay1

lcall delay1

lcall delay1

lcall delay1

mov a,#08 ;after restart the program digit chake'8',

mov 61h,a ;;at a time all six channels.

mov 62h,a

mov 63h,a

mov 64h,a

mov 65h,a

lcall bcd

lcall delay1

lcall delay1

lcall delay1

lcall delay1

mov a,#07 ;after restart the program digit chake'7',

mov 61h,a ;at a time all six channels.

mov 62h,a

mov 63h,a

mov 64h,a

mov 65h,a

lcall bcd

lcall delay1

lcall delay1

lcall delay1

lcall delay1

mov a,#06 ;after restart the program digit chake'6',

mov 61h,a ;at a time all six channels.

mov 62h,a

mov 63h,a

mov 64h,a

mov 65h,a

lcall bcd

lcall delay1

lcall delay1

lcall delay1

lcall delay1

mov a,#05 ;after restart the program digit chake'5',

mov 61h,a ;at a time all six channels.

mov 62h,a

mov 63h,a

mov 64h,a

mov 65h,a

lcall bcd

lcall delay1

lcall delay1

lcall delay1

lcall delay1

mov a,#04 ;after restart the program digit chake'4',

mov 61h,a ;at a time all six channels.

mov 62h,a

mov 63h,a

mov 64h,a

mov 65h,a

lcall bcd

lcall delay1

lcall delay1

lcall delay1

lcall delay1

mov a,#03 ;after restart the program digit chake'3',

mov 61h,a ;at a time all six channels.

mov 62h,a

mov 63h,a

mov 64h,a

mov 65h,a

lcall bcd

lcall delay1

lcall delay1

lcall delay1

lcall delay1

mov a,#02 ;after restart the program digit chake'2',

mov 61h,a ;at a time all six channels.

mov 62h,a

mov 63h,a

mov 64h,a

mov 65h,a

lcall bcd

lcall delay1

lcall delay1

lcall delay1

lcall delay1

mov a,#01 ;after restart the program digit chake'1',

mov 61h,a ;at a time all six channels.

mov 62h,a

mov 63h,a

mov 64h,a

mov 65h,a

lcall bcd

lcall delay1

lcall delay1

lcall delay1

lcall delay1

mov a,#00 ;after restart the program digit chake'0',

mov 61h,a ;at a time all six channels.

mov 62h,a

mov 63h,a

mov 64h,a

mov 65h,a

lcall bcd

lcall delay1

lcall delay1

lcall delay1

lcall delay1

ret

delay:

mov r7,#0ffh *//// assign the value 0ffh for r7 register

dale:

djnz r7,dale *//// decrement jump not zero for r7 for using,

ret this as a delay time

Function 6: For FND display

bcd:

mov a,60h ; data convert for fnd display.

lcall convart ; call the convert subprogram

mov ch1,a

mov a,61h

lcall convart

mov ch2,a

mov a,62h

lcall convart

mov ch3,a

mov a,63h

lcall convart

mov ch4,a

mov a,64h

lcall convart

mov ch5,a

mov a,65h

lcall convart

mov ch6,a

ret

convart:

inc a

mov a,@a+ pc

ret *//// in convart we convert the hex no into the

decimal no for FND display

db 03fh ; 0 for cathode +

db 06h ; fnd cathode +, binary data '0'

db 05bh ; 2 fnd hex value

db 04fh ; 3 fnd hex value

db 066h ; 4 fnd hex value

db 06dh ; 5 fnd hex value

db 07dh ; 6 fnd hex value

db 07h ; 7 fnd hex value

db 07fh ; 8 fnd hex value

db 06fh ; 9 fnd hex value

db 40h ;(-)

db 00h ; (blank)

;***************************************************

rutin:

mov 60h,#0bh ; 2e=blank hex value

clr c

mov a,33h

mov b,7fh

subb a,b

mov 3dh,a

mov a,32h

mov b,7eh

subb a,b

jnc nextt1

ljmp rev

nextt1:

mov 32h,a ;high final

mov 33h,3dh ;low final

mov a,32h ;zero chake

cjne a,#00h,as

mov a,33h

cjne a,#00h,fill_zero

as:

ret

fill_zero:

cjne a,#01h,fill_zero1

mov 33h,#00h

ljmp as

fill_zero1:

cjne a,#02h,fill_zero2

mov 33h,#00h

ljmp as

fill_zero2

cjne a,#03h,fill_zero3

mov 33h,#00h

ljmp as

fill_zero3

cjne a,#04h,fill_zero4

mov 33h,#00h

ljmp as

fill_zero4

ljmp as

rev:

mov 60h,#0ah ;for asc2nd (-)

clr c

mov a,7fh ;33h

mov b,33h ;3bh

subb a,b

mov 33h,a

;high

mov a,7eh ;32h

mov b,32h ;3ah

subb a,b

mov 32h,a

mov a,32h ;zero chake 5-1-07

cjne a,#00h,asr

mov a,33h

cjne a,#00h,fill_zeror

asr:

ret

fill_zeror:

cjne a,#01h,fill_zero1r

mov 33h,#00h

ljmp as

fill_zero1r:

cjne a,#02h,fill_zero2r

mov 33h,#00h

ljmp as

fill_zero2r

cjne a,#03h,fill_zero3r

mov 33h,#00h

ljmp as

fill_zero3r

cjne a,#04h,fill_zero4r

mov 33h,#00h

ljmp as

fill_zero4r

ljmp as

delay1:

mov r6,#0ffh *////assign the 0ffh value for r6,r7 register

mov r7,#0ffh for using as a delay

delay2:

djnz r6,delay2 *//// decrement r6,r7 untill jump not zero,

djnz r7,delay2 otherwise program executes in this delay

ret

subt: *//// in subt extra count received from the bcd

clr c (==10000)is reduced,for this 2710h moved

mov a,33h to the a & b

mov b,#10h

subb a,b

mov 33h,a

mov a,32h

mov b,#27h

subb a,b

mov 32h,a

ret

Function 7: For converting the Hexadecimal value into the Decimal value

calcu: *//// in this the capture hex value convert into the decimal no

clr c

mov a,32h ;31,34,35h

mov b,#10

div ab

mov 35h,b

mov b,#10

div ab

mov 34h,b

mov 31h,a ;end of div 32h

mov a,35h ;35*6

mov b,#6

mul ab

mov b,#10

div ab

mov 39h,b

mov 30h,a ;cary

mov a,34h ;34*6

mov b,#6

mul ab

add a,30h

mov b,#10

div ab

mov 38h,b

mov 30h,a ;cary

mov a,31h ; 31*6

mov b,#6

mul ab

add a,30h

mov b,#10

div ab

mov 37h,b

mov 36h,a

mov a,35h ;35*5

mov b,#5

mul ab

mov b,#10

div ab

mov 3dh,b

mov 30h,a ;cary

mov a,34h ;34*5

mov b,#5

mul ab

add a,30h

mov b,#10

div ab

mov 3ch,b

mov 30h,a ;cary

mov a,31h ;31*5

mov b,#5

mul ab

add a,30h

mov b,#10

div ab

mov 3bh,b

mov 3ah,a

mov a,35h ;35*2

mov b,#2

mul ab

mov b,#10

div ab

mov 41h,b

mov 30h,a ;cary

mov a,34h ;34*2

mov b,#2

mul ab

add a,30h

mov b,#10

div ab

mov 40h,b

mov 30h,a ;cary

mov a,31h ;31*2

mov b,#2

mul ab

add a,30h

mov b,#10

div ab

mov 3fh,b

mul adding

mov 44h,39h ;result

mov a,38h

add a,3dh

mov b,#10

div ab

mov 43h,b ;result

mov 30h,a ;cary

mov a,37h

add a,3ch

add a,41h

add a,30h

mov b,#10

div ab

mov 42h,b ;result

mov 30h,a ;cary

mov a,36h

add a,3bh

add a,40h

add a,30h

mov b,#10

div ab

mov 41h,b ;result

mov 30h,a ;cary

mov a,3ah

add a,3fh

add a,30h

mov b,#10

div ab

mov 40h,b ;result

mov 30h,a ;cary

mov a,33h

mov b,#10

div ab

mov 35h,b

mov b,#10

div ab

mov 34h,b

mov 33h,a

mov a,44h

add a,35h

mov b,#10

div ab

mov 44h,b

mov 30h,a

mov a,43h

add a,34h

add a,30h

mov b,#10

div ab

mov 43h,b ;dis lsb

mov 30h,a

mov a,42h

add a,33h

add a,30h

mov b,#10

div ab

mov 42h,b ;dis lsb

mov 30h,a

mov a,41h

add a,30h

mov b,#10

div ab

mov 41h,b

mov 30h,a

mov a,40h

add a,30h

mov b,#10

div ab

mov 40h,b

mov 30h,a

ret

;end of calcu prog

transfar_to_bcd: *//// in this the output of calcu: move into the FND display

mov 65h,44h

mov 64h,43h

mov 63h,42h

mov 62h,41h

mov 61h,40h

ret

;end of b_d_a_d_adding+present:

;result in 45,46,47,48,49

Function 8: For entering the value through keypad.

key_board:

begen:

mov p3,#0ffh

clr 0b0h

jnb 0b4h,get ;p2.4

jnb 0b5h,get ;p2.5

jnb 0b6h,get ;p2.6

jnb 0b7h,get

lcall delay1

setb 0b0h ;p2.0

lcall delay1

clr 0b1h ;p2.1

lcall delay1

jnb 0b4h,get ;p2.4

jnb 0b5h,get ;p2.5

jnb 0b6h,get ;p2.6

jnb 0b7h,get

lcall delay1

setb 0b1h ;p2.1

lcall delay1

clr 0b2h ;p2.2

lcall delay1

jnb 0b4h,get ;p2.4

jnb 0b5h,get ;p2.5

jnb 0b6h,get ;p2.6

jnb 0b7h,get

lcall delay1

setb 0b2h ;p2.2

lcall delay1

clr 0b3h ;p2.3

lcall delay1

jnb 0b4h,get ;p2.4

jnb 0b5h,get ;p2.5

jnb 0b6h,get ;p2.6

jnb 0b7h,get

lcall delay1

setb 0b3h ;p2.3

lcall delay1

ljmp begen

get:

lcall delay1

mov r2,p3 ;key port

clr p1.3

lcall delay1

setb P1.3

setb psw.3

inc r4

cjne r4,#06h,convert

mov r4,#0h

clr psw.3

Function 9: For displaying and storing the values from 0 to 9

convert:

clr psw.3

cjne r2,#07eh,zeroo

setb psw.3

mov a,r4

cjne a,#01h,not_zeroo5

mov 61h,#00h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_zeroo5:

cjne a,#02h,not_zeroo4

mov 62h,#00h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_zeroo4:

cjne a,#03h,not_zeroo3

mov 63h,#00h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_zeroo3:

cjne a,#04h,not_zeroo2

mov 64h,#00h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_zeroo2:

cjne a,#05h,not_zeroo1

mov 65h,#00h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

not_zeroo1:

ljmp begen

one:

clr psw.3

cjne r2,#07dh,one

setb psw.3

mov a,r4

cjne a,#01h,not_one5

mov 61h,#01h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_one5:

cjne a,#02h,not_one4

mov 62h,#01h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_one4:

cjne a,#03h,not_one3

mov 63h,#01h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_one3:

cjne a,#04h,not_one2

mov 64h,#01h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_one2:

cjne a,#05h,not_one1

mov 65h,#01h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

not_one1:

ljmp begen

two:

clr psw.3

cjne r2,#07bh,two

setb psw.3

mov a,r4

cjne a,#01h,not_two5

mov 61h,#02h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_two5:

cjne a,#02h,not_two4

mov 62h,#02h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_two4:

cjne a,#03h,not_two3

mov 63h,#02h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_two3:

cjne a,#04h,not_two2

mov 64h,#02h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_two2:

cjne a,#05h,not_two1

mov 65h,#02h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

not_two1:

ljmp begen

three:

clr psw.3

cjne r2,#077h,three

setb psw.3

mov a,r4

cjne a,#01h,not_three5

mov 61h,#03h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_three5:

cjne a,#02h,not_three4

mov 62h,#03h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_three4:

cjne a,#03h,not_three3

mov 63h,#03h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_three3:

cjne a,#04h,not_three2

mov 64h,#03h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_three2:

cjne a,#05h,not_three1

mov 65h,#03h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

not_three1:

ljmp begen

four: clr psw.3

cjne r2,#0beh,four

setb psw.3

mov a,r4

cjne a,#01h,not_four5

mov 61h,#04h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_four5:

cjne a,#02h,not_four4

mov 62h,#04h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_four4:

cjne a,#03h,not_four3

mov 63h,#04h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_four3:

cjne a,#04h,not_four2

mov 64h,#04h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_four2:

cjne a,#05h,not_four1

mov 65h,#04h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

not_four1:

ljmp begen

five:

clr psw.3

cjne r2,#0bdh,five

setb psw.3

mov a,r4

cjne a,#01h,not_five5

mov 61h,#05h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_five5:

cjne a,#02h,not_five4

mov 62h,#05h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_five4:

cjne a,#03h,not_five3

mov 63h,#05h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_five3:

cjne a,#04h,not_five2

mov 64h,#05h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_five2:

cjne a,#05h,not_five1

mov 65h,#05h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

not_five1:

ljmp begen

six:

clr psw.3

cjne r2,#0bbh,six

setb psw.3

mov a,r4

cjne a,#01h,not_six5

mov 61h,#06h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_six5:

cjne a,#02h,not_six4

mov 62h,#06h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_six4:

cjne a,#03h,not_six3

mov 63h,#06h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_six3:

cjne a,#04h,not_six2

mov 64h,#06h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_six2:

cjne a,#05h,not_six1

mov 65h,#06h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

not_six1:

ljmp begen

seven:

clr psw.3

cjne r2,#0b7h,seven

setb psw.3

mov a,r4

cjne a,#01h,not_seven5

mov 61h,#07h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_seven5:

cjne a,#02h,not_seven4

mov 62h,#07h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_seven4:

cjne a,#03h,not_seven3

mov 63h,#07h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_seven3:

cjne a,#04h,not_seven2

mov 64h,#07h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_seven2:

cjne a,#05h,not_seven1

mov 65h,#07h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

not_seven1:

ljmp begen

eight:

clr psw.3

cjne r2,#0deh,eight

setb psw.3

mov a,r4

cjne a,#01h,not_eight5

mov 61h,#08h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_eight5:

cjne a,#02h,not_eight4

mov 62h,#08h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_eight4:

cjne a,#03h,not_eight3

mov 63h,#08h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_eight3:

cjne a,#04h,not_eight2

mov 64h,#08h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_eight2:

cjne a,#05h,not_eight1

mov 65h,#08h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

not_eight1:

ljmp begen

nine:

clr psw.3

cjne r2,#0ddh,nine

setb psw.3

mov a,r4

cjne a,#01h,not_nine5

mov 61h,#09h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_nine5:

cjne a,#02h,not_nine4

mov 62h,#09h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_nine4:

cjne a,#03h,not_nine3

mov 63h,#09h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_nine3:

cjne a,#04h,not_nine2

mov 64h,#09h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

ljmp begen

not_nine2:

cjne a,#05h,not_nine1

mov 65h,#09h

clr psw.3

lcall bcd

lcall delay1

lcall delay1

lcall delay1

not_nine1:

ljmp begen

ten:

clr psw.3

cjne r2,#0dbh,ten

lcall key_store

ljmp over

Function 10: For storing the value entered by the keypad

key_store:

mov 66h,61h

mov 67h,62h

mov 68h,63h

mov 69h,64h

mov 6ah,65h

clr p1.4 *////start the solenoid coil

ret

Function 11: For comparing the value of key store (entered value) &

scale reading

comp_value:

mov a,66h

cjne a,61h,go_back

mov a,67h

cjne a,62h,go_back

mov a,68h

cjne a,63h,go_back

mov a,69h

cjne a,64h,go_back

setb p1.4 *//// stop the solenoid coil after compare the

clr p1.3 value of key_store &

lcall delay1

setb p1.3

go_back:

ret

end

The program source code of ERADIS ends here.

The further sections includes the Applications & Future Scope of ERADIS.

Applications

“Electronic Ration Distribution System(ERADIS)”- means distribution of essential commodities to a large number of people through a network on a recurring basis in an automated way. The ERADIS has many applications which can easily be implemented in real world.

The applications of ERADIS can be as follows:

Replacement for existing PDS: It can replace the existing Government Of India’s Public Distribition System (PDS) which is responsible for distributing essential commodities to a large number of people through a network of FPS (Fair Price Shops) on a recurring basis. The ERADIS also perform the same functions in an automated way.

Retail Market Sector: It can be used in retail market sector such as in Shopping Complexes, Supermarkets, Ration Shops to automate the process and to sell items without human intervention.

Large Scale implementation:

If implemented on large scale it can be used in ration processing factories and organizations for simultaneously weighing and packaging of items which are intended for selling.

Future Scope

In this era of automation we see many operations getting automated be it

consumer related operations, be it traffic related operations etc. So why

should the Public Distribution System lags behind? ERADIS is also an

automation technique which can be implemented in various day to day

disciplines and can effectively replace PDS.

The future scope of ERADIS constitutes the factors given below:

Anti-corruption tool:

Because of the automation in this field, the chances of corruption are

reduced, which is a common practice in this industry. The factors such

as Adulteration, Hoarding, Price hike of ration goods can be easily

eliminated using this approach.

Less man power:

Since the system gets automated the chances of corruption gets

reduced. As we know that a machine does not have IQ of its own, less

manpower will in turn lead to reduced corruption in this field.

Ease of access:

In the present PDS system, the people have to spend long time waiting

in queues to get ration, ERADIS can easily eliminate this problem. Also

the longevity in working is another important factor as a man cannot

work 24 hours a day but a machine can hence it can operate like an

ATM if properly maintained.

Bibliography

While working on project and on project report we referred to the following

sources:

Caliber Scales Private Limited – Technical Division.( To get the technical

specifications of the weighing machine used.

Micro Instruments – To design the PCB’s used in the project.

Datasheets of approximately all the IC’s present in the circuit (Control Unit

Components)

We also referred to various websites such as:

Google.com

Wikipedia.com

Instructables.com

And various other links of the search engines.

For programming we referred the booknamed M.A. Mazidi

(Microcontroller 8051)

We also referred various manuals provided to us during our summer

training.