This document summarizes a project to design a speed control system for a DC motor using a microcontroller. The system controls the motor speed at a desired speed regardless of load changes. It uses an AT89C52 microcontroller programmed using KEIL uVision to control the motor speed based on input from an optical encoder. The microcontroller code interfaces with an LCD display and keypad for input/output. An application software in Visual Basic collects and logs temperature data received from the microcontroller system via serial communication.

1. Developed by:
Under Supervision:
Engineer Hamid RazaEngineer Hamid Raza
Head of Electronics & Telecom Department
Comwave Institute of Science & IT, Islamabad
ZEESHAN AHMED FAROOQIZEESHAN AHMED FAROOQI
Reg. No: SUIT–06-03-77058
Roll No. SU-06-05414
B-Tech Honor (E&T)

2. • Background.
• Objective of Project.
• Scope of Project.

3. BackgroundBackground
DC motor plays a significant role in modern industrial world. There
are several types of applications where the load on the DC motor
varies over a speed range.
In home appliances, washers, dryers and compressors are good
examples. In automotive, fuel pump control, electronic steering
control, engine control and electric vehicle control are good
examples of these. In aerospace, there are a number of
applications, like centrifuges, pumps, robotic arm controls,
gyroscope controls and so on.
In all above examples, these applications may demand high
speed control accuracy and good dynamic responses.

4. Objective of Project
The main core of this project is to design a speed control
system of DC Motor by using microcontroller. This system
will be able to control the DC motor speed at desired speed
regardless the changes of load. More over time-base
functions are also implemented in his project.

5. Scope of Project
In order to achieve the objective of the project, there are
several scope had been outlined. The scope of this project
includes using KEIL uVision to program microcontroller
AT89C52, build hardware for the system, and interface the
hardware to LCD & Keypad.

6. Components of DAQComponents of DAQ
1. DC Motor
2. Optical Encoder
3. Microcontroller

7. Application of DAQApplication of DAQ
1. Unattended weather station recording (such as wind
speed / direction, temperature, relative humidity etc.
2. Unattended hydrographic recording (such as water level,
water depth, flow, temperature etc.
3. Unattended soil moisture level recording.
4. Unattended gas pressure recording.
5. Road traffic counting.
6. Process monitoring for maintenance and troubleshooting
applications and much more.
7. Black-Box is also an example of DAQ.

9. Block DiagramBlock Diagram

10. Hardware ComponentsHardware Components
• AT89C52, Microcontroller
• ADC0808, A/D Converter
• MAX232, TTL to RS232 Converter
• LM35, Temperature Sensor
• LMB162A, 16x2 Character LCD
• PC, Standard PC

11. Microcontroller
A/DConverter
MAX232
16X2 LCD
PC
LM35

12. SOFTWARE SECTIONSOFTWARE SECTIONMicrocontroller CodeMicrocontroller Code

13. Development ToolsDevelopment Tools
1. Keil uVision 3
For Code Development
2. Proteus 7 Professional
For code Simulation
3. Visual Basic 6
For Application Software Development

14. Problem:
With continuous data logging;
Size of database file becomes larger over
passage of time.
Communication link remain busy all the time.
Solution:
This problem is solved with the following
technique;
First time, data is sent to logging server &
saved temporarily.
After this, data is continuously sampled, and
compared with previously temporarily saved.
If there is change in any individual temperature
value, only then this data is sent to logging
server.

15. LCD RoutinesLCD Routines
Write Command
void writeCmd(unsigned char cmd)
{
E = 0;
P0 = cmd;
RS = 0;
RW = 0;
E = 1;
E = 0;
}
Write Data
void writeData (unsigned char msg)
{
E = 0;
P0 = msg;
RS = 1;
RW = 0;
E = 1;
E = 0;
}

16. LCD RoutinesLCD Routines
Write Character String
void writeStr (unsigned char msg [])
{
unsigned char i;
E = 0;
for(i=0;msg[i]!='0';i++)
{
P0=msg[i];
RS = 1;
RW = 0;
E = 1;
E = 0;
}
}
Goto at a Position
void gotoXY (unsigned char a, b)
{
if (a == 1)
{
b = 0x80 + b;
writeCmd (b);
}
else if (a == 2)
{
b = 0xC0 + b;
writeCmd (b);
}
}

17. LCD RoutinesLCD Routines
Write a Number
void writeNumber (unsigned int x)
{
unsigned int a;
unsigned char e,f;
a = x;
e = (a/10) + 0x30;
f = (a%10) + 0x30;
writedata (e);
writedata (f);
}
Initialize LCD
void lcd_int()
{
writeCmd(0x38); // Function Set
writeCmd(0x40); // Shift
writeCmd(0x0C); // Display Switch
writeCmd(0x06); // Input Set
writeCmd(0x01); // Clear Screen
writeCmd(0x02); // Cursor Home
}

18. ADC RoutinesADC Routines
Write a Number
unsigned char readADC (unsigned char a,b)
{
unsigned int adc;
TR0 = 1;
P1 = 0xff; // Make Port # 1 as Input
AdrsB = a;
AdrsA = b;
SC = 1; // High Low transition at Start Conversion
SC = 0; // Low High transition at Start Conversion
while (EOC == 0); // Wait for data conversion
adc = P1;
TR0 = 0;
return adc;
}

19. Serial Communication RoutinesSerial Communication Routines
Initialization of Serial Port , Timer 0 & Interrupt Configuration
void init_Ser (void)
{
TMOD = 0X22; // Use Timer 1, & Timer 0, 8-bit, Auto Re-load
TH1 = 0xFD; // 9600 Baud Rate
SCON = 0x50; // REN = 1, Mode 1 i.e. 8-bit UART
TR1 = 1; // Start Timer 1
IE = 0x92; // Global Interrupt, Serial Interrupt, Timer 0 Interrupt Enable
TH0 = 0x01; // Initial value of Timer 0 High byte
}

20. Serial CommSerial Comm
Transmitt Character & String
void SerTx (unsigned char x)
{
SBUF = x;
while (TI == 0);
TI = 0;
}
void TX_String(unsigned char msg [])
{
char z;
for (z = 0; msg[z]!='0'; z++)
{
SBUF = msg [z];
while (TI == 0);
TI = 0;
}}
Transmitt a Number
void TX_number (unsigned int x)
{
unsigned int a;
unsigned char e,f;
e = (a/10) + 0x30;
f = (a%10) + 0x30;
SBUF = e;
while (TI == 0);
TI = 0;
SBUF = f;
while (TI == 0);
TI = 0;
}}

21. MAINMAIN
MAIN Function
void main (void)
{
Alarm = 0;
Heater1 = 0; Heater2 = 0;
Heater3 = 0; Heater4 = 0;
init_Ser ();
lcd_int ();
introduction ();
send_temp ();
while (1)
{
senddata ();
alarm ();
}}
Alarm & Clock Function
void alarm (void)
{
if (alarm_bit == 1)
Alarm = 1;
msdelay (20);
Alarm = 0;
}
void clk () interrupt 1 using 1
{
clk = ~clk;
}

22. MAINMAIN
Serial Interrupt
void Ser_int (void) interrupt 4
{
unsigned char i;
if (RI == 1)
{
i = SBUF;
switch (i)
{
case ('a'):
Heater1 = 1;
break;
case ('b'):
Heater2 = 1;
break;
case ('c'):
Heater3 = 1;
break;
case ('d'):
Heater4 = 1;
break;
case ('w'):
Heater1 = 0;
break;
case ('x'):
Heater2 = 0;
break;
case ('y'):
Heater3 = 0;
break;
case ('z'):
Heater4 = 0;
break;
case ('m'):
alarm_bit = 1;
break;
case ('n'):
alarm_bit = 0;
break;
case ('r'):
send_temp2 ();
break;
}}
else {}
RI = 0;
}

23. ADC RoutinesADC Routines
void senddata (void)
{
Temp1 = readADC (0,0);
Temp2 = readADC (0,1);
Temp3 = readADC (1,0);
Temp4 = readADC (1,1);
if (Temp1 != T1_temp || Temp2 != T2_temp || Temp3 != T3_temp || Temp4 != T4_temp)
{
T1_temp = Temp1;
T2_temp = Temp2;
T3_temp = Temp3;
T4_temp = Temp4;

24. MAINMAIN
SerTx ('N');
SerTx (',');
TX_number (Temp1);
SerTx (',');
TX_number (Temp2);
SerTx (',');
TX_number (Temp3);
SerTx (',');
TX_number (Temp4);
SerTx (',');
TX_number (Heater1);
SerTx (',');
TX_number (Heater2);
SerTx (',');
TX_number (Heater3);
SerTx (',');
TX_number (Heater4);
SerTx (',');
TX_number (alarm_bit);
SerTx (',');
SerTx ('@');

25. MAINMAIN
clr ();
writeStr (txt1);
writeNumber (Temp1);
gotoXY (1,9);
writeStr (txt2);
writeNumber (Temp2);
gotoXY (2,0);
writeStr (txt3);
writeNumber (Temp3);
gotoXY (2,9);
writeStr (txt4);
writeNumber (Temp4);
msdelay (100);
clr ();
writeStr (txt10);
writeNumber (Heater1);
gotoXY (1,9);
writeStr (txt11);
writeNumber (Heater2);
gotoXY (2,0);
writeStr (txt12);
writeNumber (Heater3);
gotoXY (2,9);
writeStr (txt13);
writeNumber (Heater4);
msdelay (30);
}
else {}
}

26. Application SoftwareApplication Software
Development Plate formDevelopment Plate form
Visual Basic 6Visual Basic 6

27. Application Software CodeApplication Software Code
Data Receive Event
Private Sub MSComm1_OnComm()
If (MSComm1.CommEvent = comEvReceive) Then
Text3.Text = MSComm1.Input
Dim strSerial As String
Dim arr As Variant
If (Text3.Text Like "N") Then
c = 1
End If
If c = 1 Then
Text2.Text = Text2.Text + (Text3.Text)

28. If (Text3.Text Like "@") Then
strSerial = Text2.Text
arr = Split(strSerial, ",")
Label1(0).Caption = " " & arr(1)
Label1(1).Caption = " " & arr(2)
Label1(2).Caption = " " & arr(3)
Label1(3).Caption = " " & arr(4)
c = 0
Text2.Text = ""
Text3.Text = ""
Application Software CodeApplication Software Code

29. ' Gric Sec
fg.TextMatrix(fg.Rows - 1, 0) = CStr(fg.Rows - 1)
fg.TextMatrix(fg.Rows - 1, 1) = CStr(Now)
fg.TextMatrix(fg.Rows - 1, 2) = arr(1)
fg.TextMatrix(fg.Rows - 1, 3) = arr(2)
fg.TextMatrix(fg.Rows - 1, 4) = arr(3)
fg.TextMatrix(fg.Rows - 1, 5) = arr(4)
fg.TextMatrix(fg.Rows - 1, 6) = arr(5)
fg.TextMatrix(fg.Rows - 1, 7) = arr(6)
fg.TextMatrix(fg.Rows - 1, 8) = arr(7)
fg.TextMatrix(fg.Rows - 1, 9) = arr(8)
fg.TextMatrix(fg.Rows - 1, 10) = arr(9)
totalrec.Caption = "Total Records:" + CStr(fg.Rows - 1)
Application Software CodeApplication Software Code

30. ' DB Sec
totalrec.Caption = "Total Records: " + CStr(fg.Rows - 1)
rs.AddNew
rs.Fields("Sr No").Value = CStr(fg.Rows - 1)
rs.Fields("Date").Value = Now
rs.Fields("Temp1").Value = Val(fg.TextMatrix(fg.Rows - 1, 2))
rs.Fields("Temp2").Value = Val(fg.TextMatrix(fg.Rows - 1, 3))
rs.Fields("Temp3").Value = Val(fg.TextMatrix(fg.Rows - 1, 4))
rs.Fields("Temp4").Value = Val(fg.TextMatrix(fg.Rows - 1, 5))
rs.Fields("Heater1").Value = Val(fg.TextMatrix(fg.Rows - 1, 6))
rs.Fields("Heater2").Value = Val(fg.TextMatrix(fg.Rows - 1, 7))
rs.Fields("Heater3").Value = Val(fg.TextMatrix(fg.Rows - 1, 8))
rs.Fields("Heater4").Value = Val(fg.TextMatrix(fg.Rows - 1, 9))
rs.Fields("Alarm").Value = Val(fg.TextMatrix(fg.Rows - 1, 10))
rs.Update
fg.Rows = fg.Rows + 1
Application Software CodeApplication Software Code

31. If Option2.Value = False Then
j = 0
k = 0
For i = 0 To 3
j = i * 2
k = j + 1
If ((Val(Label1(i).Caption) < (VScroll1(j).Value))) Then
a1(i).FillColor = &HFF&
Image1(i) = hon
MSComm1.Output = Chr(97 + i) ' Heater ON
MSComm1.Output = Chr(110) ' Alarm ON
Application Software CodeApplication Software Code

32. Else
If (Val(Label1(i).Caption) > (VScroll1(k).Value)) Then
a1(i).FillColor = &H8000000F&
Image1(i) = hof
MSComm1.Output = Chr(119 + i) ' Heater OFF
MSComm1.Output = Chr(110) ' Alarm OFF
Application Software CodeApplication Software Code

33. Else
If ((Val(Label1(i).Caption) > (VScroll1(j).Value))) Then
a1(i).FillColor = &H8000000F
MSComm1.Output = Chr(110) ' Alarm OFF
End If
End If
End If
Next i
End Sub
Application Software CodeApplication Software Code