Intelligent pcb drilling machine

“INTELLIGENT PCB DRILLING MACHINE”
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
Dr. J. J. Magdum College of Engineering, Jaysingpur Page 1

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 O RCAD 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
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
LCD Display
Fig 2.2 :BLOCK DIAGRAM OF PROPOSED SYSTEM
COMPUTER
X Min
X Max
Y Min
Y Max
Z Min
Z Max
PCB’S are designed using PCB designing softwares like Orcad, PADS,
PC
Interfacewith
RS232
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 the n
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.

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

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
SettingsRinkuDesktop"
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
INTIALISE HARDWARE,
STACK,SERIAL PORT
DISPLAY COLLEGE,
PROJECT NAME
IS
COMMAND ?
YES
IS
CMD = D ?
DRILL ON OFF
NO
IS
CMD = Y ?
MOVE Y AXIS
NO
IS
CMD = X ?
MOVE X AXIS
NO
IS
CMD = Z ?
MOVE Z AXIS
NO
IS
CMD = H ?
ECHO CMD
NO
YES
YES
YES
YES
YES
NO

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

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