Intelligent pcb drilling machine

“INTELLIGENT PCB DRILLING MACHINE”

Dr. J. J. Magdum College of Engineering, Jaysingpur

CHAPTER 1 – INTRODUCTION

1.1 AIM OF THE PROJECT:

This project is mainly commercial purpose applicable project. This

would be helpful for students related to electronics field. The development of

electronic circuit usually uses PCB or Printed Circuit Board. One of the processes in

making PCB is to make a hole. The aim of this project was to reduce the time and

labour required for drilling holes in PCB using simple, user friendly and cost effective

method, as PCBs are extensively used in electronics. In the making of a PCB, after

etching process, the PCB will be placed to this system and then it will be drilled

automatically according to user commands.

1.2. HISTORICAL BACKGROUND:

This project was first started by Stephen Williams; he loaded up a nice

freeware PCB layout program. Many years ago he did PC board work for aerospace

companies up until around 1984 when PC CAD systems were just coming into being.

Since then he has been computing and wound up owning a couple ISP's and an

amusements company dealing with vintage arcade video games. This prompted him to

layout some simple boards like audio amplifiers and converters. These projects were

very home brew, breadboard or simple single sided boards, limited quantities.

FIG.1.2.1:TREADITIONAL PCB DRILL

M/C



1.3. CONVENTIONAL PCB DRILLING MACHINE:

Drilling machine is a single purpose machine for the production of holes. It

comes in many shapes and sizes, from small hand-held power drills to bench mounted

and floor-mounted models. Apart from drilling some drilling machines can perform

other operations such as tapping large or small holes, reaming, counter boring and

countersinking.

The two main categories of drilling equipment are the basic hand and power-

feed drilling machines which is further classified as bench type drilling machines,

pillar type drilling machines, column-type drilling machines, radial drilling machines,

numerically controlled drilling machines, multiple spindle drilling machines, gang

drilling machines, and turret drilling machines. These drilling equipment are designed

for high-speed production and industrial shops.

Drilling of the PCBs is inherent work in electronic industries or the place

where electronic systems are comes in account. Every PCB should be drilled

accurately so that system manufacturer can build the circuitry properly on it. Now

days PCB of electronics circuitries are drilled manually. In this process first PCB is

etched with some chemical. This etching involves the exact position of the points that

driller is going to drill at. Then drilling is done. The alignment of drilling machine is

done manually. The general picture of the drilling machine is given bellow. As we can

see, it has a platform that holds the PCB on it. And the drilling equipment is fitted so,

it can move in vertical direction. This vertical axis is moved manually to drill the

PCB.

FIG 1.3.1: CONVENTIONAL PCB

DRILLING MACHINE



1.3.1. DISADVANTAGES OF CONVENTIONAL PCB DRILLING MACHINE:

This system has some disadvantages like cracking of PCB. Drill

shifting also can happen here. Actually drill shift is responsible for cracking of the

PCB which make all PCB wasted, off cores wastage of time and money. Some of the

circuit boards even had hundreds of holes! It can be very frustrating if you make an

error when drilling one of the last holes, and you have to start all over again.

Disadvantages of Present PCB drilling machines:

Less accuracy:

We can easily say that the system which is operated manually has no

fix accuracy. As it highly dependent on human skill the drill shifting, wrong

alignment of PCB and PCB platform, change of drill size can be happens. Which is

undoubtablely ends into wastage of our printed circuit board.

Drill shifting:

FIG 2.1: DRILL STRUCTURE IN PCB

Depends upon human skill

The present system is highly dependent on human skills. If worker

doing the drill is not well skilled definitely we will get our PCB converted into

garbage.



A. Time consumption:

As we have seen present is operated manually, it requires more time to drill a

particular PCB. As worker need to make sure that drilling machine is going to drill at

exact right place, this confirmation requires some time to complete. And it is

unavoidable as PCB drilling is very keen and careful work.

B. Probability of mistakes as it has human involves :

It’s a world known rule that machine does not make mistakes provided; human

has not made any wrong settings in it.

C. Capacity of work:

Due to man operated work it has limited capacity than machine.



CHAPTER 2-PROPOSED SYSTEM DESIGN IDEA

2.1 PROJECT FEATURES:

The system designed has the following capabilities:

Ability to be operated manually.

Ability to show the entered values to the user.

Ability to easily move the machine from one place to another.

Ability to start/stop motor manually.

Ability to start/stop motor automatically.

2.2 DESIGN STRATEGY:

This project deals with drilling of the PCB’s (Printed Circuit Boards)

automatically. PCB’s are normally designed using ORCAD Software. While

designing PCB Layout in the ORCAD layout software a TAP file is created. Using

this TAP file, which consists of X axis & Y axis position and the drill bit details we

are giving the orders for the X axis & Y axis drivers to drive the X axis &Y axis dc

motors to take the positions on the drilling machine. And then Z axis which is

attached with drilling motor drills that point on the PCB.



The process of making the project will be completed by dividing it into

different phases. The four phases involved will be:

Phase 1:

Mechanical design it consist of arrangement of all mechanical hardware by

using old inkjet dot-matrix printer. It consists of belt and pulley

arrangement, stepper motor etc.

Design of chassis with using of suitable material design of support rods.

Design of rod holders.

Selection of screws for fitting all parts together.

Phase 2:

Selection of stepper motors

Design of stepper motor drivers.

Selection of drill motor.

Design for servo motor driver

Phase 3:

Programming using visual basic for microcontroller 89C51.

Creation of CNC machine window in visual basic.

Phase 4:

Installation and assembly of all parts.

Commissioning of the machine.

Testing and trial.



2.3 SYSTEM INTRODUCTION:

PCBs drilling machine mainly consists of three blocks P.C (for

software purpose), Controller Block and the Drilling machine. Computer which has

software’s like ORCAD & Visual Basics forms the base for giving directions to the

Controller Block. Microcontroller is very vital part in controlling the movements of

axis on the drill machine. It also gives orders, when to start drilling and when to stop.

There are three stepper motors connected in X, Y and Z axis. And they will be

controlled or operated by the microcontroller AT89C51 connected to it. Of the three

axis, two axis are used to move the PCB platform in x and y directions. And the one

remaining that is z axis moves drilling machine in the vertical direction.

As the PCB comes at the desired position, the third stepper motor

moves the drilling machine along the third z (vertical) axis to drill there. This saves

time and reduces errors due to manual handling and also gives much accuracy too.

To make graphical sketch of the desired PCB and send all information

to the microcontroller through RS323C.To make the drill file and Gerber information.

Uses ORCAD & VB softwares for thework. ORCAD for designing the PCB

skeleton.Visual Basics for extract the information to provide to AT89C51.

As we complete the graphical presentation of the PCB layout, the

software itself creates a file containing all the information about the PCB drilling,

hole size, and hole positions on which we are going to make drill. All the data about

the point where we have to drill is created in the ORCAD software, this information

involves two dimensional details of the point. Now, the data about the dimensions of

particular point’s position on the PCB position and the hole size etc is called as

Gerber. And the all Gerber files of all drilling points is called as Drill file.

Fig 2.1.:Drilling Skeleton on ORCAD.



Table 2.1: Drill Chart.

CNC Drilling is an automatic drilling process where the information of

the hole position, sequence and hole diameter is stored in file (text file). This text file

is generated by a cad software like ORCAD, PADS, EAGLE PCB design Tools.

Our task is to read that hole position, sequence and hole diameter and

send to mechanical system, means convert that information into movement of XYZ

axis of mechanical system. Software developed using VB 6.0 is used to read that text

file and it converts all info into movement of XYZ axis via serial port (COM Port of

PC).

In that text file all Dimensions are in mils, 1000mil = 1Inch = 25.4mm.

The drill file is shown below,

T1C0.038F200S100 This indicates 0.038mil hole diameter.

X000500Y000500 x = 50mil y = 50mil

X000500Y003500

T3C0.040F200S100 This indicates 0.040mil hole diameter

X014500Y004000 x = 1450mil y = 400mil

X014500Y005000



2.4 BLOCK DIAGRAM DISCRIPTION

Fig 2.2 :BLOCK DIAGRAM OF PROPOSED SYSTEM

PCB’S are designed using PCB designing softwares like Orcad, PADS,

EAGLE PCB design Tools etc. While designing PCB a TAP file is created, in this

TAP file details of drilling like drill bit, X & Y positions are saved in it.

This TAP file is taken in the program provided along with this project.

When this file is opened in this program all the positions of X & Y axis are taken and

then sent to the Microcontroller 89C51 through the serial communication IC

MAX232. Here RS232 cod is used for communication between PC & the

Microcontroller.

Then Microcontroller, according to the X & Y positions on the PCB,

drives the X & Y axis DC Stepper motors. When position is taken then

Microcontroller gives order to drill motor relay & also to Z axis driver to start drilling

at that point. Then it takes the next position given in the TAP file and drills that

position. It continues drilling the positions given in the file until next drill bit is given.

It continues in this way till the whole files are drilled. LCD is used to give the curre nt

status of the drilling file.

Stepper Driver X Stepper

Motor

Stepper Driver Y Stepper

Motor

Stepper Driver Z Stepper

Motor

Drill Motor Driver Drilling

Machine

DC Motor

Micro-

Controller

AT89C51

COMPUTER

PC

Interfacewith

RS232

X Min

X Max

Y Min

Y Max

Z Min

Z Max

LCD Display



CHAPTER 3-MECHANICAL DESIGN PHILOSOPHY AND APPROACH

All the mechanisms and linkages which are used in project are made up of old

scrap printer. This printer is of dot matrix type. This type of four printers are

disassembled and parts such as supporting steel rods, belt and pulley mechanism,

stepper motor, stepper motor head etc. are used in model making. Following figure

shows the old type dot matrix printer.

There are some proprieties that must be found for each axis movement:

1- Smooth.

2- Easy.

3- On the same pattern.

FIG 3.1:TIPICAL DOT MATRIX PRINTER



3.1 PRINTERS DISASSEMBLED PARTS

FIG 3.1.2: BELT PULLEY ASSEMBLY

FIG 3.1.3: F.V OF PRINTER



FIG 3.1.4: COMPLETE ASSEMBLY VIEW



PHASE 1 : Mechanical Design

Mechanical design it consist of arrangement of all mechanical hardware by

using old inkjet dot-matrix printer. It consists of belt and pulley

arrangement, stepper motor etc.

Design of chassis with using of suitable material design of support rods.

Design of rod holders.

Selection of screws for fitting all parts together.

Fig 3.1.5: DESIGN OF MACHINE IN PRO ENGINEERING SOFTWARE



DRILLING TOOL

Above drilling tool make holes in board as want. It has Dc servo motor. It

requires Electricaldrill with DC voltage input 12V and links it on Z-axis.

Fig 3.1.6 : Drill Head

CHASSIS

FIG 3.1.7:CHASSIS CATIA DRAWING

Material For Chassis :

Hylam industrial laminated sheet is used as base material in chassis and

providing good structure to it .It is a thermosetting phenol, formed from an

elimination reaction of phenol with formaldehyde. It sustain the vibration and force

crated during the drilling operation.

FIG 3.1.8: MATERIA

http://en.wikipedia.org/wiki/Elimination_reaction

http://en.wikipedia.org/wiki/Phenol

http://en.wikipedia.org/wiki/Formaldehyde



L SHAPED ATTACHMENT

Fig 3.1.9 : L SHAPED ATTACHMENT

GUIDE BAR

Fig3.1.10: GUIDE BAR

It is directly taken from printer head support. In every printer one rod is

present, such types of four rods are require for construction . It is made up of steel.



BARSLIDER

It is made up of plastic and got from printer. It gives smooth sliding through the bar.

Fig 3.1.11 : BAR SLIDER

MOTOR

Fig 3.1.12: STEPPER MOTER

Typical printer motors have the following specs +2 to +24 Volts, uses 600

mA per phase, with a coil resistance around 30 ohms (unipolar) or 6 ohms (bipolar).

Holding torque is probably around 0.2 Nm for unipolar and 0.1 Nm for bipolar.

The above values can differ from printer to printer, but they are usually near these

values.



3.2 PCB DRILLING MECHANICAL STRUCTURAL ARRANGEMENT:

After gathering all metal parts and accessories required for assembling the

procedure of making the machine is listed below step by step each step has a

corresponding listed in figure

1. Start from the base

2. Install four steel supports

3. Install rods for supporting of y axis

4. Fix the motors

5. Place the pulley supports and make it tightness

6. Install cross roller guide

7. Screw the table on supporting rod

8. Complete the machine with limit switch

Fig 3.2.1 REQUIRED Y AXIS TABLE SLIDING MOVEMENT



Fig 3.2.2:Z AXIS VERTICAL SLIDING MOVEMENT DRILLING HEAD



COMPLETE ASSEMBLY OF PCB DRILLING MACHINE:



CHAPTER 4-ELECTRONICS CONTROL SYSTEM

4.1 MAIN CIRCUIT DESIGN:



4.2 MAIN PCB LAYOUT:

4.3 POWER SUPPLY :

Through power supply we are getting different voltages to

meet our requirements. These are 5, 12 and 24 volts with maximum 250

Watt. 12 volts are used to operate motor for opening and closing of door

and relays. 24 volts are being used to operate gear train dc motor to move

the cabin up and down.

Fig 4.3.1: POWER SUPPLY



Fig 4.3.2: POWER SUPPLY CKT.

4.4 LM78XX SERIES VOLTAGE REGULATORS:

Features:

Output current in excess of 1A

Internal thermal overload protection

No external components required

Output transistor safe area protection

Internal short circuit current limit

Available in the aluminum TO-3 package

Voltage Range:

LM7805C 5V

LM7812C 12V

LM7815C 15V



4.5 GENERAL DESCRIPTION OF LM78XX:

The LM78XX series of three terminal regulators is available with several

fixed output voltages making them useful in a wide range of applications. One of

these is local on card regulation, eliminating the distribution problems associated with

single point regulation.

The voltages available allow these regulators to be used in logic systems,

instrumentation, Hi-Fi, and other solid state electronic equipment. Although designed

primarily as fixed voltage regulator these devices can be used with external

components to obtain adjustable voltages and currents. The LM78XX series is

available in an aluminum TO-3 package which will allow over 1.0A load current if

adequate heat sinking is provided. Current limiting is included to limit the peak output

current to a safe value. Safe area protection for the output transistor is provided to

limit internal power dissipation. If internal power dissipation becomes too high for the

heat sinking provided, the thermal shutdown circuit takes over preventing the IC from

overheating. Considerable effort was expanded to make the LM78XX series of

regulators easy to use and minimize the number.



4.6 CIRCUIT DIAGRAM LM7805

Fig 4.16.1: CKT OF LM7805

We need the regulated 5 V output for the most of the IC’s used in our

system. Now the output of bridge rectifier is unregulated DC. To get 5V regulated Dc

out put from it we have used regulator IC 7805.Following fig shows the pin out

diagram of the regulator IC 7805.

The 7805 series is a three terminal positive voltage regulator IC which

gives regulated 5V D.C. output. The maximum input voltage that can be applied to

input pin is the 35 V. The minimum difference between input and output voltage

required is the 2 V. The pin no 1 is the input pin where the unregulated input voltage

is applied. Pi no.2 is connected to the ground, whereas pin no.3 is the output pin at

which the regulated 5V output can be obtained.



CHAPTER 5- CONTROLLER BLOCK ASSEMBLY

5.1 MICROCONTROLLER AT89C51 DESCRIPTION:

The AT89C51 is a low-power, high-performance CMOS 8-bit

microcomputer with 4K bytes of Flash programmable and erasable read only memory

(PEROM). The device is manufactured using Atmel’s high-density nonvolatile

memory technology and is compatible with the industry-standard 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, the Atmel AT89C51 is a

powerful microcomputer which provides a highly-flexible and cost-effective solution

to many embedded control applications.

Fig 5.1.1: MICROCONTROLLER AT89C51



5.2 FEATURES

• Compatible with MCS-51™ Products

• 4K Bytes of In-System Reprogrammable Flash Memory

Endurance: 1,000 Write/Erase Cycles

• Fully Static Operation: 0 Hz to 24 MHz

• Three-level Program Memory Lock

• 128 x 8-bit Internal RAM

• 32 Programmable I/O Lines

• Two 16-bit Timer/Counters

• Six Interrupt Sources

• Programmable Serial Channel

• Low-power Idle and Power-down Modes



5.3 BLOCK DIAGRAM:

Fig 5.3.1:BLOCK DIAGRAM OF AT89C51



5.4 CHARACTERISTICS:

The AT89C51 provides the following standard features: 4K bytes of

flash, 128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, five vector two-

level interrupt architecture, a full duplex serial port, on-chip oscillator and clock

circuitry. In addition, the AT89C51 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

5.5 PIN DIAGRAM:

FIG 5.5.1: PIN DIAGRAM



5.6 PIN DESCRIPTION:

VCC:

Supply voltage

GND:

Ground.

Port 0:

Port 0 is an 8-bit open-drain bi-directional 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. Port 0 may also be configured to be the multiplexed low order

address/data bus during accesses to external program and data memory. In this mode

P0 has internal minimize. Port 0 also receives the code bytes during Flash

programming, and outputs the code bytes during program verification. External

minimize are required during program verification.

Port 1:

Port 1 is an 8-bit bi-directional I/O port with internal minimize. The Port 1 output

buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins they are

pulled high by the internal minimize and can be used as inputs. As inputs, Port 1 pins

that are externally being pulled low will source current (IIL) because of the internal

minimize. Port 1 also receives the low-order address bytes during Flash programming

and verification.

Port 2:




that are externally being pulled low will source current (IIL) because of the internal

minimize. Port 2 emits the high-order address byte during fetches from external

program memory and during accesses to external data memory that uses 16-bit

addresses (MOVX @DPTR). In this application, it uses strong internal pull-ups when

emitting 1’s.



Port 3:




that are externally being pulled low will source current (IIL) because of the minimize.

Port 3 also serves the functions of various special features of the AT89C51 as listed

below: Port 3 also receives some control signals for Flash programming and

verification.

RST:

Reset input. A high on this pin for two machine cycles while the oscillator is running

resets the device.

ALE/PROG:

Address Latch Enable 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. In normal operation ALE is emitted at a constant rate of 1/6the

oscillator frequency, and may be used for external timing or clocking purposes. Note,

however, that one ALE pulse is skipped during each access to external Data Memory.

If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With

the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the

pin is weakly pulled high. Setting the ALE-disable bit has no effect if the

microcontroller is in external execution mode.

PSEN:

Program Store Enable is the read strobe to external program memory. When the

AT89C51 is executing code from external program memory, PSEN is activated twice

each machine cycle, except that two PSEN activations are skipped during each access

to external data 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. Note, however, that if lock bit 1 is programmed, EA will be internally latched

on reset. EA should be strapped to VCC for internal program executions. This pin also

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

for parts that require 12-volt VPP.

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

operating circuit.

XTAL2: Output from the inverting oscillator amplifier.

Oscillator characteristics:

FIG 5.6.1:LADDER DIAGRAM

XTAL1 and XTAL2 are the input and output, respectively, of an inverting

amplifier which can be configured for use as an on-chip oscillator, as shown in

Figure 1. Either a quartz crystal or ceramic resonator may be used. To drive the

device from an external clock source, XTAL2 should be left unconnected while

XTAL1 is driven as shown in Figure. There are no requirements on the duty cycle

of the external clock signal, since the input to the internal clock ing circuitry is

through a divide-by-two flip-flop, but minimum and maximum voltage high and

low time specifications must be observed.



IDLE MODE:

In idle mode, the CPU puts itself to sleep while all the on chip peripherals remain

active. The mode is invoked by software. The content of the on-chip RAM and all the

special functions registers remain unchanged during this mode. The idle mode can be

terminated by any enabled interrupt or by a hardware reset. It should be noted that

when idle is terminated by a hard ware reset, the device normally resumes program

execution, from where it left off, up to two machine cycles before the internal reset

algorithm takes control. On-chip hardware inhibits access to internal RAM in this

event, but access to the port pins is not inhibited. To eliminate the possibility of an

unexpected write to a port pin when Idle is terminated by reset, the instruction

following the one that invokes Idle should not be one that writes to a port pin or to

external memory.



CHAPTER 6 - STEPPER MOTOR DRIVER

Phase 2:

Selection of stepper motors

Design of stepper motor drivers.

Selection of drill motor.

Design for servo motor driver

6.1 WORKING STEPPER MOTOR

Stepper motors consist of a permanent magnet rotating shaft, called the

rotor, and electromagnets on the stationary portion that surrounds the motor, called

the stator. Figure 6.1.1, illustrates one complete rotation of a stepper motor. At

position 1, we can see that the rotor is beginning at the upper electromagnet, which is

currently active (has voltage applied to it). To move the rotor clockwise (CW), the

upper electromagnet is deactivated and the right electromagnet is activated, causing

the rotor to move 90 degrees CW, aligning itself with the active magnet. This process

is repeated in the same manner at the south and west electromagnets until we once

again reach the starting position.

In the bellow example, we used a motor with a resolution of 90 degrees or

demonstration purposes. In reality, this would not be a very practical motor for most

applications. The average stepper motor's resolution -- the amount of degrees rotated

per pulse -- is much higher than this. For example, a motor with a resolution of 5

degrees would move its rotor 5 degrees per step, thereby requiring 72 pulses (steps) to

complete a full 360 degree rotation.

As you can see in Figure 2, in the first position only the upper electromagnet is

active, and the rotor is drawn completely to it. In position 2, both the top and right

electromagnets are active, causing the rotor to position itself between the two active

poles. Finally, in position 3, the top magnet is deactivated and the rotor is drawn all

the way right. This process can then be repeated for the entire rotation.



Fig 6.1.1

Fig 6.1.2



There are several types of stepper motors. 4-wire stepper motors contain only

two electromagnets; however the operation is more complicated than those with three

or four magnets, because the driving circuit must be able to reverse the current after

each step. For our purposes, we will be using a 6-wire motor.

As you can see in Figure 2, in the first position only the upper electromagnet is

active, and the rotor is drawn completely to it. In position 2, both the top and right

electromagnets are active, causing the rotor to position itself between the two active

poles. Finally, in position 3, the top magnet is deactivated and the rotor is drawn all

the way right. This process can then be repeated for the entire rotation.

There are several types of stepper motors. 4-wire stepper motors contain only

two electromagnets; however the operation is more complicated than those with three

or four magnets, because the driving circuit must be able to reverse the current after

each step. For our purposes, we will be using a 6-wire motor.

Unlike example motors which rotated 90 degrees per step, real-world motors

employ a series of mini-poles on the stator and rotor to increase resolution. An

example of a multipole motor can be seen in Figure 3. In position 1, the north pole of

the rotor's permanent magnet is aligned with the south pole of the stator's

electromagnet. In position 2, the upper electromagnet is deactivated and the next one

to its immediate left is activated, causing the rotor to rotate a precise amount of

degrees. In this example, after eight steps sequence repeats .



6.2 LM6228 (STEPPER MOTOR CONTROLLER & DRIVER) FEATURES:

OPERATING SUPPLY VOLTAGE FROM 8 TO 52V

2.8A OUTPUT PEAK CURRENT (1.4 A RMS)

RDS(ON) 0.73W TYP. VALUE @ Tj = 25°C

OPERATING FREQUENCY UP TO 100KHz

NON DISSIPATIVE OVERCURRENT PROTECTION

DUAL INDEPENDENT CONSTANT tOFF PWM CURRENT

CONTROLLERS

FAST/SLOW DECAY MODE SELECTION

FAST DECAY QUASI-SYNCHRONOUS RECTIFICATION

DECODING LOGIC FOR STEPPER MOTOR FULL AND HALF STEP

DRIVE

CROSS CONDUCTION PROTECTION

THERMAL SHUTDOWN

UNDER VOLTAGE LOCKOUT

INTEGRATED FAST FREE WHEELING DIODES



Relay Basics:

Relays are one of the oldest, simplest, and yet, easiest and most useful devices.

Before the advent of the mass produced transistor, computers were made from either

relays or vacuum tubes, or both.

A relay, quite simply, is a small machine consisting of an electromagnet (coil),

a switch, and a spring. The spring holds the switch in one position, until a current is

passed through the coil. The coil generates a magnetic field which moves the switch.

It's that simple. You can use a very small amount of current to activate a relay, and the

switch can often handle a lot of current.

Relays really are not a big deal. They are relatively easy to use, and are very

forgiving of stupidity. For many applications, a relay is the only way to go.



6.3 CIRCUIT DESCRIPTION:

POWER STAGES AND CHARGE PUMP:

The L6228 integrates two independent Power MOS Full Bridges. Each

Power MOS has an DS(ON) =0.73W (typical value @ 25°C), with intrinsic fast

freewheeling diode. Switching patterns are generated by the PWM Current Controller

and the Phase Sequence Generator (see below). Cross conduction protection is

achieved using a dead time (tDT = 1mstypical value) between the switch off and

switch on of two Power MOSFETSs in one leg of a bridge. Pins VSA and VSB

MUST be connected together to the supply voltage VS. The device operates with a

supply voltage in the range from 8V to 52V. It has to be noticed that the RDS(ON)

increases of some percents when the supply voltage is in the range from 8Vto

12V.Using N-Channel Power MOS for the upper transistor sin the bridge requires a

gate drive voltage above the power supply voltage. The bootstrapped supply vo ltage

VBOOT is obtained through an internal Oscillator and few external components to

realize a charge pump circuit. The oscillator output (VCP) is a square wave at 600

KHz (typical) with 10V amplitude.

FIG 6.3.1 PIN DESCRIPTION OF LM6228



HALF STEP MODE:

A HIGH logic level on the HALF/FULL input selects Half Step Mode. Figure 16

shows the motor current waveforms and the state diagram for the Phase Sequencer

Generator. At Start-Up or after a RESET the Phase Sequencer is at state 1. After each

clock pulse the state changes following the sequence 1,2,3,4,5,6,7,8,… if CW/CCW is

high (Clockwise movement) or 1,8,7,6,5,4,3,2,… if CW/CCW is low

(Counterclockwise movement).

NORMAL DRIVE MODE (Full-step two-phase-on):

A LOW level on the HALF/FULL input selects the Full Step mode. When the low

level is applied when the state machine is at an ODD numbered state the Normal

Drive Mode is selected. Figure Fig. 17 shows the motor current waveform state

diagram for the state machine of the Phase Sequencer Generator. The Normal Drive

Mode can easily be selected by holding the HALF/FULL input low and applying a

RESET. AT start -up or after a RESET the State Machine is in state1. While the

HALF/FULL input is kept low, state changes following the sequence 1,3,5,7,… if

CW/CCW is high (Clockwise movement) or 1,7,5,3,… if CW/CCW is low

(Counterclockwise movement).

NON-DISSIPATIVE OVERCURRENT PROTECTION:

The L6228 integrates an Over current Detection Circuit (OCD) for full protection.

This circuit provides protection against a short circuit to ground or between two

phases of the bridge. With this internal over current detection, the external current

sense resistor normally used and its associated power dissipation are eliminated.

To implement the over current detection, a sensing element that delivers a small but

precise fraction of the output current is implemented with each high side power MOS.

Since this current is a small fraction of the output current there is very little additional

power dissipation. This current is compared with an internal reference current IREF.

When the output current reaches the detection threshold (typically 2.8A) the OCD

comparator signals a fault condition. When a fault condition is detected, the EN pin is

pulled below the turn off threshold (1.3V typical) by an internal open drain MOS with

a pull down capability of 4mA. By using an external R-C on the EN pin.



FIG 6.3.2: STEPPER DRIVER PCB LAYOUT

FIG 6.3.3: PCB LAYOUT

CHAPTER 7-SERIAL INTERFACE



7.1 RS232 STANDARDS

RS232: DB9 Connector:

In telecommunications, RS-232 is a standard for serial binary data

interconnection between a DTE (Data terminal equipment) and a DCE (Data Circuit-

terminating Equipment). It is commonly used in computer serial ports.

Scope of the Standard:

The Electronic Industries Alliance (EIA) standard RS-232-C [3] as of 1969 defines:

Electrical signal characteristics such as voltage levels, signaling rate, timing

and slew-rate of signals, voltage withstand level, short-circuit behavior,

maximum stray capacitance and cable length

Interface mechanical characteristics, pluggable connectors and pin

identification

Functions of each circuit in the interface connector

Standard subsets of interface circuits for selected telecom applications



The standard does not define such elements as character encoding (for

example, ASCII, Baudot or EBCDIC), or the framing of characters in the data stream

(bits per character, start/stop bits, parity). The standard does not define protocols for

error detection or algorithms for data compression.

The standard does not define bit rates for transmission, although the standard

says it is intended for bit rates lower than 20,000 bits per second. Many modern

devices can exceed this speed (38,400 and 57,600 bit/s being common, and 115,200

and 230,400 bit/s making occasional appearances) while still using RS-232

compatible signal levels.

Details of character format and transmission bit rate are controlled by the

serial port hardware, often a single integrated circuit called a UART that converts data

from parallel to serial form. A typical serial port includes specialized driver and

receiver integrated circuits to convert between internal logic levels and RS-232

compatible signal levels.

In this circuit the MAX 232 IC used as level logic converter. The

MAX232 is a dual driver/receiver that includes a capacitive voltage generator to

supply EIA 232 voltage levels from a single 5v supply. Each receiver converts EIA-

232 to 5v TTL/CMOS levels. Each driver converts TLL/CMOS input levels into EIA-

232 levels.



7.2 RS232 CIRCUIT DESIGN:

In this circuit the microcontroller transmitter pin is connected in the MAX232

T2IN pin which converts input 5v TTL/CMOS level to RS232 level. Then T2OUT

pin is connected to reviver pin of 9 pin D type serial connector which is directly

connected to PC.

In PC the transmitting data is given to R2IN of MAX232 through transmitting

pin of 9 pin D type connector which converts the RS232 level to 5v TTL/CMOS

level. The R2OUT pin is connected to receiver pin of the microcontroller. Likewise

the data is transmitted and received between the microcontroller and PC or other

device vice versa.



7.3 MAX232:

The MAX232 device is a dual driver/receiver that includes a capacitive

voltage generator to supply EIA-232 voltage levels from a single 5-V supply. Each

receiver converts EIA-232 inputs to 5-V TTL/CMOS levels. These receivers have a

typical threshold of 1.3 V and a typical hysteresis of 0.5 V, and can accept -30 to +30

V inputs. Each driver converts TTL/CMOS input levels into EIA-232 levels.



7.4 FEATURES:

Operates With Single 5-V Power Supply

Two Drivers and Two Receivers

-30 to +30 V Input Levels

Low Supply Current of 8 mA Typical

Designed to be Interchangeable With Maxim MAX232

Package Options Include Plastic Small-Outline (D, DW) Packages and

Standard Plastic (N) DIPs

APPLICATIONS:

Battery-Powered Systems

Terminals

Modems

Computers



CHAPTER 8 -DISPLAY UNIT

8.1 LCD’s:

Features:

16*2 lines display

5*7 dot matrix display

8 bit data interface

Recently a number of projects are using intelligent liquid crystal display

(LCD)

It not only displays numbers but also characters & graphics.

This is in contrast to LED’s which are limited to numbers & few characters.

There are numbers of LCD’s with different shapes & sizes. We are using 16*2

type of LCD.

Back light:

LED with a choice of colors

Bright and even back lighting

Long life expectancy, more than 100,000 hours

Simple to drive. Needs +5 volts only

Brightness can be easily adjusted

CCFL (Cold Cathode Florescent Light)

Paper white, best for large graphic displays

Less power consumption than LED’s

DISPLAY TYPE

Positive image (Dark dots on light background)

Negative image (Light dots on dark background)



FIG 8.1.1: LCD DISPLAY

DISPLAY CHARACTER POSITION AND CHARACTER ADDRESS 16 *2 LCD:

16 x 2: HDM16216H-2, HDM16216H-4, HDM16216H-5, HDM16216H-B,

HDM16216H-S, HDM16216L-2, HDM16216L-5, HDM16216L-6, HDM16216L-7,

HDM16216L-B, HDM16216L-S



8.2 LCD Pin Descriptions:

PIN ASSIGNMENT FOR > 80 CHARACTER DISPLAYS

Pin

number

Symbol Level I/O Function

1 GND Ground

2 VCC + 5 V

3 CONTRAST Gnd

4 E Enable

5 RS Register Select

6 R/W Read Write

7 DB0 Data Line

8 DB1 Data Line

9 DB2 Data Line

10 DB3 Data Line

11 DB4 Data Line

12 DB5 Data Line

13 DB6 Data Line

14 DB7 Data Line

15 VCC + 5 V

16 GND Gnd



1. VCC, VSS and VEE:--

While VCC and VSS provide the +5V and ground, respectively, VEE is used for

controlling LCD contrast.

2. RS, register select:--

There are two very important registers inside the LCD. The RS pin is used for their

selection

If RS=0 , the instruction command code register is selected, allowing the user to send

a command such as clear display , cursor at home, etc.

If RS=1, the data register is selected, allowing the user to send data to be displayed on

the LCD.

3. R/W read/ write:--

R/W input allows the user to write information to the LCD or read information from

it.

R/W=1 when reading.

R/W=0 when writing.

4. E, enable:--

The enable pin is used by the LCD to latch information presented to its data pins.

When data is supplied to data pins, a high-to- low pulse must be applied to this pin in

order for the LCD to latch in the data present at the data pins. This pulse must be as

minimum as 450ns wide.



Operational Overview:

1] Busy Flag (BF)

When the busy flag is HIGH level, it indicates that the controller is in the internal

operation mode and the next instruction will not be accepted. When R/W is ‘1’ and

RS is ‘0’ the busy flag is output from DB. The next instruction must be written after

the busy flag goes low.

2] Address Counter (AC)

The address counter (AC) generates the address for the DD RAM, the CG

RAM and for the cursor display. When an instruction code for DD or CG RAM

address is written to the controller, after deciding whether it is DD RAM or CG RAM,

the address information is transferred to AC. After writing into (or reading from) DD

or CG RAM display data, AC is automatically incremented (decremented). The data

of the AC is output to DB0-DB6 when RS is ‘0’ and R/W is ‘1’.

3] Character Generator ROM (CG ROM)

The character generator ROM generates 5 x 7 dot or 5 x 10 dot character patterns

from 8- bit character codes. It can generate 160 types of 5 x 7 dot character patterns

and 32 types of 5 x 10 dot character patterns. When the 8-bit character code of a CG

ROM is written to the DD RAM, the character pattern of the CG ROM corresponding

to the code is displayed on the LCD display position corresponding to the DD RAM.



4] Character Generator RAM (CG RAM)

The character generator RAM (CG RAM) is the RAM with which the user can

generate character patterns by program. The CG RAM has the capacity to store 8

kinds of 5 x 7 dots or 4 kinds of 5 x 10 dots. Programming of these character patterns

is explained in CG RAM programming.

5] Display Data RAM (DD RAM)

The display data RAM (DD RAM) stores display data represented in 8-bit

(hexadecimal) character codes. Its capacity is 80 x 8 bits, or 80 characters. The

display data RAM (DD RAM) that is not used for display can be used as general data

RAM. Depending on the 8- bit character code that is written into the DD RAM. LCD

will select the character pattern either from Character Generator RAM (CG RAM) or

from Character Generator ROM (CG ROM).

6] Underline/Blinking Block Cursor

Cursor is under the control of the MPU Programmed. The display of the cursor on the

LCD is made at a position corresponding to the DD RAM address set to the address

counter (AC).



CHAPTER 9- HARDWARE REQUIREMENT

9.1 HARDWARE REQUIREMENT:

Stepper motors-3,

Transformer-2- 230V to 12V ac. step down.

1. Main Power Supply

Diode-1N4007-4, led-1, resistors-1, capacitors (in mF) - 1000-1, 10-2, 0.1-2,

Voltage regulator- 7805C-1, 7812CT-1.

2. Microcontroller PCB

*power supply: diode-IN4007-4, led-1, resistors-1,

Capacitors (in mF)- 1000-1, 10-2,0.1-2,

Voltage regulator- 7805C- 1.

*AT89C51, 3 axis driver pins, input from transformer &

Output to stepper driver circuit, crystal oscillator-11.0592 MHz, capacitors-0.1mf-2,

Resistor-1, pot, LCD notch, limitdef switch's notches-6.

Reset circuit:

Reset switch, capacitors-10mf-1, resistors-10k-1, and diode-1-1N4148.

3. Stepper Driver & Controller PCB

Input from 89V51,

Stepper controller & driver LMS6228, resisots-4, capacitors-3.3nf-1, 0.1mf-1, preset,

resistors 5W-2, capacitor-3.3nf-2, 1000mf-1,

Power diode-1N5408-8,

Input from power supply & output to stepper motor.

MOC 7811 to check maximum and minimum XYZ axis limits. LCD DISPLAY 16x2



Chapter 10 - SOFTWARE REQUIREMENT

Phase 3:

Programming using visual basic for microcontroller 89C51.

Creation of CNC machine window in visual basic.

10.1 SOFTWARE REQUIREMENT:

ORCAD Software– for designing the PCB LAYOUT. And our VB based Program in

which we give the drill file.

COMPUTER SYSTEM:

To make graphical sketch of the desired pcb and send all information to the

microcontroller through RS323C.

To make the drill file and Gerber information.

Uses ORCAD & VB softwares for the work.

ORCAD for designing the PCB skeleton.

Visual Basics for extract the information to provide to AT89C51.

10.2. VISUAL BASIC:

Microsoft Visual Basic, the fastest and easiest way to create applications for

Microsoft Windows. Whether you are an experienced professional or brand new to

windows programming, Visual Basics provides you with a complete set of tools to

simplify rapid application development.

WHAT IS IN VISUAL BASIC?

“Visual” part refers to method used to create Graphical User Interface

(GUI). Rather than writing numerous lines of code to describe appearance and

location of an interface element, we simply add pre-built objects into place on a

screen. If you have every used drawing program such as paint you already have most

of skills necessary to create an effective user interface.



The “Basic” part refers to BASIC (Beginners All purpose Symbolic

Instruction Code) language, a language used by more programmers than any other

language in the history of computing. Visual Basic has involved from original BASIC

language and now contains several hundred Active X technologies allow you to use

Microsoft Excel Spreadsheet and other window applications. You can even automate

application and object created using professional enterprise edition of Visual Basic. In

this project we have connected our hardware with VB. Because, the student data

stored in memory chip is shown in the VB and connection of the software to the

project hardware is done by using MSCOM of VB.

Fig.10.1.1: VB Form for PCB Drilling Machine



10.3 Program code in VISUAL BASIC:

Dim SerialTxRxError AsBoolean

Dim SerialRxBytes AsInteger

Dim AutoManual AsBoolean

Dim steps AsString

Dim DelayComplete AsBoolean

Dim DrillFileName AsString

Dim DrillSelectFlag AsBoolean

Dim PauseFlag AsBoolean

Dim EndOfDrillFlag AsBoolean

PrivateSub Form1_Load(ByVal sender As System.Object, ByVal e As

System.EventArgs) HandlesMyBase.Load

' check available serial ports

For i AsInteger = 0 ToMy.Computer.Ports.SerialPortNames.Count - 1

cboCommPorts.Items.Add(My.Computer.Ports.SerialPortNames(i))

Next

' auto = true, manual = false

AutoManual = True

PauseFlag = False

' Disable all controls

GroupBoxManualControl.Enabled = False

GroupBoxDistance.Enabled = False

GroupBoxStepperSteps.Enabled = False

GroupBoxDrillSelect.Enabled = False

GroupBoxStatus.Enabled = False

GroupBoxStartStop.Enabled = False

BtnOpenFile.Enabled = False

BtnPause.Enabled = False

TextBoxCNCDrill.Enabled = False

BtnComClose.Enabled = False

BtnAutoManual.Enabled = False


EndSub

PrivateSub BtnOpenFile_Click(ByVal sender As System.Object, ByVal e

As System.EventArgs) Handles BtnOpenFile.Click

Try

OpenFileDialogCNC.InitialDirectory = "C:\Documents and

Settings\Rinku\Desktop"

OpenFileDialogCNC.Filter = "Hex files (*.tap)|*.tap"

OpenFileDialogCNC.FileName = ""

OpenFileDialogCNC.ShowDialog()

Dim stream_reader AsNew StreamReader(OpenFileDialogCNC.FileName)

' Save path of opened file

DrillFileName = OpenFileDialogCNC.FileName

TextBoxCNCDrill.Text =

My.Computer.FileSystem.ReadAllText(OpenFileDialogCNC.FileName)

DrillInfoLine = stream_reader.ReadLine()



If DrillInfoLine <>"%"Then

MsgBox("NOT a CNC Drill File")

TextBoxCNCDrill.Text = ""

Else

GroupBoxStartStop.Enabled = True

BtnStart.Enabled = True

EndIf

Catch Ex As Exception

MsgBox(Ex.Message, MsgBoxStyle.Critical, "")

EndTry

EndSub

PrivateSub BtnStart_Click(ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles BtnStart.Click

Dim drillbit AsDouble

Dim XAxis AsDouble

Dim YAxis AsDouble

Dim CurrentXaxis AsInteger

Dim CurrentYaxis AsInteger

Dim NextXaxis AsInteger

Dim NextYaxis AsInteger

Dim Xsteps AsInteger

Dim Ysteps AsInteger

Dim Zsteps AsInteger

Dim XStepsSign AsString

Dim YStepsSign AsString

Dim stream_reader AsNew StreamReader(DrillFileName)

Try

EndOfDrillFlag = False

BtnStart.Enabled = False

BtnPause.Enabled = True

GroupBoxDistance.Enabled = True

CurrentXaxis = 0

CurrentYaxis = 0

NextXaxis = 0

NextYaxis = 0

Xsteps = 0

Ysteps = 0

XStepsSign = "+"

YStepsSign = "+"

' read for % data


' read drill bit info


Do



Application.DoEvents()

If DrillInfoLine(0) = "T"Then

drillbit = CDbl(DrillInfoLine(3) &

DrillInfoLine(4) & DrillInfoLine(5) & DrillInfoLine(6) &

DrillInfoLine(7))

drillbit = drillbit * 1000 ' convert

to mil

drillbit = (25.4 * drillbit) / 1000 ' convert

to mm

TextBoxDrillBit.Text = drillbit

GroupBoxDrillSelect.Enabled = True

MsgBox("Please Use Drill Bit = "& drillbit &" mm

& Click Drill Select Button")

EndIf

' wait for drill bit change

Do


If DrillSelectFlag = TrueThen

DrillSelectFlag = False

ExitDo

EndIf

If PauseFlag = TrueThen

TextStatus.Text = "Operation Paused"

EndIf

Do


If PauseFlag = FalseThen

ExitDo

EndIf

Loop

Loop

' Send x And y location to hardware

Do



If DrillInfoLine(0) = "T"Then

ExitDo

ElseIf DrillInfoLine(0) = "X"Then

' read x axis data

XAxis = CDbl(DrillInfoLine(1) &


DrillInfoLine(5) & DrillInfoLine(6))

TextBoxXAxisMil.Text = XAxis

XAxis = XAxis / 10 ' convert to mil

XAxis = XAxis / 13.3 ' DEVIDE BY step

resolution

NextXaxis = CInt(XAxis)

If NextXaxis = CurrentXaxis Then

Xsteps = 0



XStepsSign = "+"

ElseIf NextXaxis > CurrentXaxis Then

Xsteps = NextXaxis - CurrentXaxis

XStepsSign = "+"

ElseIf NextXaxis < CurrentXaxis Then

Xsteps = CurrentXaxis - NextXaxis

XStepsSign = "-"

EndIf

TextBoxXAxisSteps.Text = Xsteps

' x axis data to hardware

SendData("x") ' command

SendData(XStepsSign)

Steps2Hardware(Xsteps)

CurrentXaxis = NextXaxis

' read y axis data

YAxis = CDbl(DrillInfoLine(8) &


DrillInfoLine(12) & DrillInfoLine(13))

TextBoxYAxisMil.Text = YAxis

YAxis = YAxis / 10 ' convert to

mil

YAxis = YAxis / 13.3 ' devide by

step resolution

NextYaxis = CInt(YAxis)

If NextYaxis = CurrentYaxis Then

Ysteps = 0

YStepsSign = "+"

ElseIf NextYaxis > CurrentYaxis Then

Ysteps = NextYaxis - CurrentYaxis

YStepsSign = "+"

ElseIf NextYaxis < CurrentYaxis Then

Ysteps = CurrentYaxis - NextYaxis

YStepsSign = "-"

EndIf

TextBoxYAxisSteps.Text = Ysteps

' y axis data to hardware

SendData("y")

SendData(YStepsSign)

Steps2Hardware(Ysteps)

CurrentYaxis = NextYaxis

' Turn On Drill Machine

SendData("d")

SendData("1")

Zsteps = TextBoxZAxisSteps.Text

' z axis data to hardware

SendData("z")

SendData("+")

Steps2Hardware(Zsteps)



Zsteps = TextBoxZAxisSteps.Text

' z axis data to hardware

SendData("z")

SendData("-")

Steps2Hardware(Zsteps)

ElseIf DrillInfoLine(0) = "M"Then

EndOfDrillFlag = True

' Turn Off Drill Machine

SendData("d")

SendData("0")

' go to home position for next job

ExitDo

EndIf



EndIf

Do


If PauseFlag = FalseThen

ExitDo

EndIf

Loop

Loop

If EndOfDrillFlag = TrueThen

EndOfDrillFlag = False

BtnStart.Enabled = True


TextBoxXAxisMil.Text = ""

TextBoxYAxisMil.Text = ""

TextBoxDrillBit.Text = ""



MsgBox("End Of Drill File")

ExitDo

EndIf

Loop' main loop



EndTry

EndSub

PrivateSub BtnComConnect_Click(ByVal sender As System.Object, ByVal e

As System.EventArgs) Handles BtnComConnect.Click

Try

TextStatus.Text = ("Opening "& cboCommPorts.Text

&"..........")

If SerialPort1.IsOpen Then

SerialPort1.Close()

EndIf

SerialPort1.PortName = cboCommPorts.Text



SerialPort1.Open()

If SerialPort1.IsOpen Then

' clear serial out buffer

SerialPort1.DiscardOutBuffer()

SerialPort1.Encoding = System.Text.Encoding.Default

' clear serial in buffer

SerialPort1.DiscardInBuffer()

BtnComConnect.Enabled = False

cboCommPorts.Enabled = False

BtnComClose.Enabled = True

GroupBoxStatus.Enabled = True

TextStatus.Text = ("Opened "& cboCommPorts.Text)

If SendData("h") = TrueThen

TextStatus.Text = ("Opened "& cboCommPorts.Text

&", CNC Hardware Detected")

BtnAutoManual.Enabled = True

' enable auto mode

BtnOpenFile.Enabled = True

TextBoxCNCDrill.Enabled = True

Else

TextStatus.Text = ("Opened "& cboCommPorts.Text

&", No CNC Hardware Detected")

MsgBox("No CNC Hardware Detected Plz Check

Connection")

EndIf

Else

TextStatus.Text = ""

MsgBox("ComPort "& cboCommPorts.Text &" can't open")

EndIf



EndTry

EndSub

PrivateSub BtnComClose_Click(ByVal sender As System.Object, ByVal e

As System.EventArgs) Handles BtnComClose.Click

Try

SerialPort1.Close()

TextStatus.Text = ("Closed "& cboCommPorts.Text)

' Disable all controls



GroupBoxStepperSteps.Enabled = False



GroupBoxStartStop.Enabled = False





BtnComConnect.Enabled = True

cboCommPorts.Enabled = True

BtnComClose.Enabled = False


BtnAutoManual.Enabled = False

TextBoxCNCDrill.Text = ""



EndTry

EndSub

PrivateSub TimerProcess_Tick_1(ByVal sender As System.Object, ByVal e

As System.EventArgs) Handles TimerProcess.Tick

TimerProcess.Enabled = False

SerialTxRxError = True

EndSub

PrivateSub BtnAutoManual_Click(ByVal sender As System.Object, ByVal e

As System.Even000000tArgs) Handles BtnAutoManual.Click

AutoManual = Not AutoManual

If AutoManual = TrueThen

' enable auto mode

BtnOpenFile.Enabled = True

TextBoxCNCDrill.Enabled = True


BtnAutoManual.Text = "Auto Mode"

TextStatus.Text = "Auto Mode Selected"

Else

' enable manual mode

GroupBoxManualControl.Enabled = True



BtnAutoManual.Text = "Manual Mode"

TextStatus.Text = "Manual Mode Selected"

EndIf

EndSub

PrivateSub BtnXplus_Click(ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles BtnXplus.Click


steps = TextBoxStepsManual.Text

If steps > 400 Then

TextBoxStepsManual.Text = "1"

MsgBox(" Step No. Should Be <= 400")


Else

SendData("x")

SendData("+")

Steps2Hardware(steps)



EndIf

EndSub

PrivateSub BtnXminus_Click(ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles BtnXminus.Click



If steps > 400 Then




Else

SendData("x")

SendData("-")


EndIf

EndSub

PrivateSub BtnYplus_Click(ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles BtnYplus.Click



If steps > 100 Then




Else

SendData("y")

SendData("-")


EndIf

EndSub

PrivateSub BtnYminus_Click(ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles BtnYminus.Click



If steps > 100 Then




Else

SendData("y")

SendData("+")


EndIf

EndSub

PrivateSub BtnZplus_Click(ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles BtnZplus.Click



If steps > 1000 Then






Else

SendData("z")

SendData("+")


EndIf

EndSub

PrivateSub BtnZminus_Click(ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles BtnZminus.Click



If steps > 1000 Then




Else

SendData("z")

SendData("-")


EndIf

EndSub

PrivateSub BtnDrill_Click(ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles BtnDrill.Click

' Turn On Drill Machine

SendData("d")

SendData("1")


SendData("z")

SendData("+")



SendData("z")

SendData("-")


' Turn Off Drill Machine

SendData("d")

SendData("0")

EndSub

PublicFunction Steps2Hardware(ByVal steps AsString) AsBoolean

Dim SendDataFlag AsBoolean

Dim Echo AsString

Try

If steps < 10 Then

steps = "0000"& steps

ElseIf steps < 100 Then

steps = "000"& steps


steps = "00"& steps


steps = "0"& steps

EndIf



For i AsInteger = 0 To 4

If SendData(steps(i)) = FalseThen

SendDataFlag = False

MsgBox("Communication Error With Hardware")

ExitFor

EndIf

SendDataFlag = True

Next

TextStatus.Text = "Waiting for Operation Complete"

If SendDataFlag = TrueThen

Do


SerialRxBytes = SerialPort1.BytesToRead

If SerialRxBytes > 0 Then

Echo = Val(SerialPort1.ReadByte)

If Echo = Val(Asc("R")) Then

TextStatus.Text = "Operation Complete"


ExitDo

Else

TextStatus.Text = "Operation Not

Complete"

EndIf

If Echo = Val(Asc("A")) Then

MsgBox(" Xmax or Xmin ox Ymax or Ymin or

Zmax or Zmin Sensor Active Or Wrong Step Move Sign")


ExitDo

EndIf

EndIf

Loop

EndIf



EndTry

EndFunction

PublicFunction SendData(ByVal Data AsString) AsBoolean

Dim Echo AsString

Try

SerialPort1.DiscardInBuffer() ' clear serial input

buffer

' send Data to hardware

SerialPort1.Write(Data)

' wait for echo

TimerProcess.Interval = 10000 ' mili seconds

TimerProcess.Enabled = True

SerialTxRxError = False

' Wait for Echo

Do




SerialRxBytes = SerialPort1.BytesToRead

LoopUntil (SerialRxBytes > 0 Or SerialTxRxError = True)

If SerialTxRxError = TrueThen

SerialTxRxError = False

SendData = False

Else

' disable timer

TimerProcess.Enabled = False

Echo = Val(SerialPort1.ReadByte)

If Echo = Val(Asc(Data)) Then

SendData = True

Else

SendData = False

EndIf

EndIf



EndTry

EndFunction

PrivateSub BtnDrillSelect_Click(ByVal sender As System.Object, ByVal

e As System.EventArgs) Handles BtnDrillSelect.Click

DrillSelectFlag = True


EndSub

PrivateSub BtnPause_Click(ByVal sender As System.Object, ByVal e As

System.EventArgs) Handles BtnPause.Click

PauseFlag = Not PauseFlag



Else

TextStatus.Text = "Operation Resumed"

EndIf

EndSub

EndClass00



10.4 PROGRAMMING OF MICROCONTROLLER:

KEIL µVISION:

Keil µVision is used for the programming of this system. Keil was founded in 1986 to

market add-on products for the development tools provided by many of the silicon

vendors. Keil implemented the first C compiler designed from the ground-up

specifically for the 8051 microcontroller.

Keil provides a broad range of development tools like ANSI C compiler, macro

assemblers, debuggers and simulators, linkers, IDE, library managers, real-time

operating systems and evaluation boards for 8051, 251, ARM, and XC16x/C16x/

ST10 families.

The µVision3 integrated development environment (IDE) is a Windows-based

software development platform that combines a robust editor, project manager, and

makes facility. µVision3 integrates all tools including the C compiler, macro

assembler, linker/locator, and HEX file generator. The µVision3 IDE offers numerous

features such as:

Source code editor,

Device database for configuring the development tool setting,

Project manager for creating and maintaining projects,

Integrated make facility for assembling, compiling, and linking embedded

applications,

True integrated source- level Debugger with high-speed CPU and peripheral

simulator,

Advanced interface for software debugging in the target hardware and for

connection to Keil ULINK,

Flash programming utility for downloading the application program into Flash

ROM,

The µVision3 IDE offers numerous features and advantages that help you

quickly and successfully develop embedded applications. They are easy to use

and are guaranteed to help you achieve your design goals.



CHAPTER 11- FLOW CHART

11.1 WORKING FLOWCHART:

START

ISCOMMAND ?

ISCMD = D ?

DRILL ON OFF

ISCMD = Y ?

MOVE Y AXIS

ISCMD = X ?

MOVE X AXIS

ISCMD = Z ?

MOVE Z AXIS

ISCMD = H ?

ECHO CMD

NO

YES

NO

YES

YES

YES

YES

YES

NO

NO

NO

NO

INTIALISE HARDWARE,STACK,SERIAL PORTDISPLAY COLLEGE,

PROJECT NAME



11.2 AXIS FLOW CHART



CHAPTER 12- ADVANTAGES & DISADVANTAGES,

APPLICATIONS

ADVANTAGES:

Intelligent PCB Drilling Machines machines can be used continuously 24 hours a day, 365 days a year and only need to be switched off for occasional maintenance.

Intelligent PCB Drilling Machines machines are programmed with a design which can then be manufactured hundreds or even thousands of times. Each

manufactured product will be exactly the same. Less skilled/trained people can Intelligent PCB Drilling Machines unlike

manual lathes / milling machines etc.. which need skilled engineers.

Intelligent Intelligent PCB Drilling Machines Drilling Machines machines can be updated by improving the software used to drive the machines

Training in the use of Intelligent PCB Drilling Machines is available through the use of ‘virtual software’. This is software that allows the operator to practice using the INTELLIGENT PCB DRILLING MACHINE machine on

the screen of a computer. The software is similar to a computer game. INTELLIGENT PCB DRILLING MACHINE machines can be programmed

by advanced design software such as Pro/DESKTOP®, enabling the manufacture of products that cannot be made by manual machines, even those used by skilled designers / engineers.

Modern design software allows the designer to simulate the manufacture of his/her idea. There is no need to make a prototype or model. .

One person can supervise many INTELLIGENT PCB DRILLING MACHINE

machines as once they are programmed they can usually be left to work by themselves. Sometimes only the cutting tools need replacing occasionally.

A skilled engineer can make the same component many times. However, if each component is carefully studied, each one will vary slightly. A INTELLIGENT PCB DRILLING MACHINE machine will manufacture each

component as an exact match.

Disadvantages:

Less accuracy than CNC machine.

Slow speed than CNC machines

APPLICATIONS:

1. In college project laboratories.

2. Small scale circuit designing Industries



CHAPTER13 - FUTURE ENHANCEMENT

FUTURE ENHANCEMENT:

Stepper motors are used to move the PCB and drilling machine. Now they can

provide 200-400 rpm in normal operating conditions. If anyone write stepper

algorithms it can provide up to 1200 rpm variation . Again if servo motors is used

then these rpm ratings can acquire value of 5000-7000.

CNC machines are the advance part of drilling machine. They have tool

changing facility. Also more than one PCB can be drilled at a time. These CNC

machines have much greater speed with great accuracy.

The stepper motors has more than 200 steps. That is stepper motors can give

minimum step size of 0.9 degree. Whereas the proposed system has stepper motor hag

step size of 1.8 degree.



CHAPTER 14- CONCLUSION

Cost =

The cost of actual m/c which is available is approx. 30000 to 60000/- . This

cost has been reduced by nearly 50% . This will help the small scale industries in

making their shop floor atomized

Raw material =

The material used in making of this project has been used from the waste of

old dot matrix printer. Hence the there is a reuse or recycle of old electronic waste.

This is a major issue that current world faceing

Accuracy =

The work done by human can cause various error like positioning error, time

consuming etc. This has been reduced by the project designed .

Time consumptions =

The time taken by human in drilling any PCB with accuracy is very much say

about 10 min. this time has been reduce to 3-4 min. . This feature of the project will

definitely be a reason for the higher rate of production.

Thus the Moto of any industry of

“GREAT PROFIT WITH LESS INVESTMENT ” is satisfied by our project



CHAPTER 15 - COST SHEET

MATERIAL REQUIRED NO OF PIECE COST PER PIECE {RS}

TOTAL COST IN{RS}

Stepper Motor 3 700 2100.00

Rails 6 150 900.00

Pulleys 2 100 200.00

Belt 2 50 100.00

Clamps 12 25 300.00

Sliders 3 200 600.00

Micro Controller(AT89C51) 1 300.00 300.00

Transformer 2 250.00 500.00

SMPS 1 400.00 400.00

Drill Motor 1 1200 1200.00

Stepper driver 3 200 600.00

Diode 2 15.00 30.00

Printed Circuit Board 1 200.00 200.00

Wires 1 200.00 200.00

Capacitors 4 10.00 40.00

Resistance 5 10.00 50.00

Regulator 1

100.00 100.00

IC base 1

100.00 100.00

Interface RS232 1

250 250.00

Time Relay 1 250.00 250.00

8870IC 1 150.00 150.00

Transistor(2977) 1

300.00 300.00

LCD Display 1 300.00 300.00

model design

3000 3000.00

Traveling expenses

2000.00 2000.00

Other expenses

1000.00 1000.00

TOTAL

15270



CHAPTER 16 - BIBILOGRAPHY

REFERENCE:

Kenneth J. Ayala -The 8051 Micro controller Architecture, Programming &

Applications Pen ram.

M.A. Mazidi -The 8051 Micro controller and Embedded Systems Pearson

Education.

Noel Jerke- The Complete References Visual Basic 6

Atmel Data Book.

Websites:

o www.nationalsemiconductors.com

o www.atmel.com

o www.dallassemi.com

Intelligent pcb drilling machine

Engineering

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