This document contains details of 11 practical experiments conducted using an AT90S8535 microcontroller. Each experiment is summarized in 3 sentences or less: 1. Toggle the state of LEDs connected to two ports by alternately setting the ports high and low with a 0.5 second delay. 2. Simulate an 8-bit binary counter by incrementing the port value and lighting LEDs one by one with a 0.2 second delay. 3. Generate a 1 second delay by toggling an LED connected to one port using a timer overflow interrupt that increments a counter.

1. INDEX
Sr.No. Name of Practical Date Remark Sign
1. Toggle Port LED 07/01/2015
2. Simulate Binary Counter at
Port
07/01/2015
3. Generate delay using TIMER_0 14/01/2015
4. Stepper
Motor(clockwise/Anticlockwise)
14/01/2015
5. Generating square wave at port
pin
21/01/2015
6. Generating Triangular wave at
port pin
21/01/2015
7. Sine wave generation using
look-up table
21/01/2015
8. Microcontrollers
communicating over a serial
link
28/01/2015
9. Read switch-status from i/p
port and
display at o/p port
04/02/2015
10. using Input Capture Pin (ICP),
measure pulse width & display
at o/p port
11/02/2015
11. Working of Interrupt_0 on
falling
edge
18/02/2015

2. Practical No: 1 –“Toggle Port LED”
Aim:
Write a program in Assembly/C programming language to alternately ON/OFF LEDs connected to
two different ports. Draw appropriate circuit diagram to demonstrate the above problem. Write
description of the above program and explain hardware and software part of above program. Draw
o/p waveform if necessary.
Softwares used:
CodeVisionAVR Software.
WAVRASM Software.
Proteus Professional 6.5 SP5 Software.
Components used:
AT90S8535 Microcontroller.
LED’s
Logic:
1. Setting a logic-high on the LSB of PORTA and logic-low on PORTB.
2. Setting a delay of 0.5 sec.

3. Circuit Diagram:

4. Program:
#include <90s8535.h>
#include <delay.h>
// Declare your global variables here
void main(void)
{
PORTA=0xff;
DDRA=0xff;
PORTB=0xff;
DDRB=0xff;
while (1)
{
PORTA=PORTA^PORTB;
PORTB=PORTB^PORTA;
};
}
Conclusion:
By using the delay function provided by the program we can turn off and on the leds on any ports of
our choice.

5. Practical No.2- “Simulate Binary Counter at Port”
Aim:
Write a program in Assembly/C programming language to simulate binary counter (8 bit) on LEDs
use one of the four ports of Mc of output interface to 8 LEDs (LEDs should glow one – by – one) .
Explain hardware and software part of above program.
Draw o/p waveform if necessary.
Softwares used:
CodeVisionAVR Software.
WAVRASM Software.
Proteus Professional 6.5 SP5 Software.
Components used:
AT90S8535 Microcontroller.
LED’s
Logic:
Setting a delay of 0.5 sec.

6. Circuit Diagram:

7. Program :
#include <90s8535.h> #include
<delay.h>
void main(void)
{
PORTA=0x00;
DDRA=0xff;
while (1)
{
//PORTA=0x01;
DDRA=0x00;
PORTA=PORTA+PORTA;
DDRA=PORTA;
if(PORTA==0x00)
{
PORTA=0x01;
}
delay_ms(200);
};
}

8. Practical No: 3 -“Generate delay using TIMER_0”
Aim:
Write a program in Assembly/C programming language to alternately ON/OFF LEDs connected to
two different ports. Draw appropriate circuit diagram to demonstrate the above problem. Write
description of the above program and explain hardware and software part of above program. Draw
o/p waveform if necessary.
Softwares used:
CodeVisionAVR Software.
WAVRASM Software.
Proteus Professional 6.5 SP5 Software.
Components used:
AT90S8535 Microcontroller.
LED’s
Logic:
3. Setting a logic-high on the LSB of PORTA and logic-low on PORTB.
4. Setting a delay of 1 sec.

9. Circuit Diagram:

10. Program:
#include <90s8535.h>
unsigned int timecount=0;
interrupt [TIM0_OVF] void time0_ovf_isr(void)
{
TCNT0=6;
if(++timecount==2)
{
PORTA=PORTA^0x80;
timecount=0;
}
}
void main(void)
{
DDRA=0x80;
TCCR0=0x02;
TCNT0=0x00;
TIMSK=0x01;
#asm("sei");
while (1)
{
};
}

11. Practical No: 4 “Stepper Motor” (clockwise/Anticlockwise)
Aim:
Write a program in Assembly/C programming language to alternately ON/OFF LEDs connected to
two different ports. Draw appropriate circuit diagram to demonstrate the above problem. Write
description of the above program and explain hardware and software part of above program. Draw
o/p waveform if necessary.
Softwares used:
CodeVisionAVR Software.
WAVRASM Software.
Proteus Professional 6.5 SP5 Software.
Components used:
AT90S8535 Microcontroller.
LED’s
Logic:
5. Setting a logic-high on the LSB of PORTA and logic-low on PORTB.
6. Setting a delay of 1 sec.

12. Circuit Diagram:

13. Program:
#include <90s8535.h> #include
<delay.h>
int count1, count2 ;
void main(void)
{
PORTA=0x01;
DDRA=0xFF;
PORTB=0x01;
DDRB=0xFF;
count1 = 0 ; count2
= 0 ;
while (1)
{
delay_ms(200) ;
PORTA = PORTA + PORTA ;
count1++ ;
if(count1 == 7)
{
count1 = 0 ;
delay_ms(200) ; PORTA
= 0x01 ;
}
delay_ms(200) ;
PORTB = PORTB + PORTB ;
count2++ ;
if(count2 == 7)
{
count2 = 0 ;
delay_ms(200) ; PORTB
= 0x01 ;
}
}
}

14. Practical No: 5 “Generating square wave at port pin”
Aim:
Write a program in Assembly/C programming language to alternately ON/OFF LEDs connected to
two different ports. Draw appropriate circuit diagram to demonstrate the above problem. Write
description of the above program and explain hardware and software part of above program. Draw
o/p waveform if necessary.
Softwares used:
CodeVisionAVR Software.
WAVRASM Software.
Proteus Professional 6.5 SP5 Software.
Components used:
AT90S8535 Microcontroller.
LED’s
Logic:
7. Setting a logic-high on the LSB of PORTA and logic-low on PORTB.
8. Setting a delay of 1 sec.

15. Circuit Diagram:

16. Program:
#include <90s8535.h>
unsigned int timecount=0;
interrupt[TIM0_OVF] void timeo_ovf_isr(void)
{
TCNT0 = 6;
if(++timecount==2)
{
PORTA=PORTA^0x80;
timecount=0;
}
}
void main(void)
{
DDRA = 0x80;
TCCR0 = 0x02;
TCNT0 = 0x00;
TIMSK = 0x01;
#asm("sei");
while (1)
{
};
}

17. Practical No: 6 “/2015”
Aim:
Write a program in Assembly/C programming language to alternately ON/OFF LEDs connected to
two different ports. Draw appropriate circuit diagram to demonstrate the above problem. Write
description of the above program and explain hardware and software part of above program. Draw
o/p waveform if necessary.
Softwares used:
CodeVisionAVR Software.
WAVRASM Software.
Proteus Professional 6.5 SP5 Software.
Components used:
AT90S8535 Microcontroller.
LED’s
Logic:
9. Setting a logic-high on the LSB of PORTA and logic-low on PORTB.
10. Setting a delay of 1 sec.

18. Circuit Diagram:

20. Program:
#include <90s8535.h>
int count = 0 ;
void main(void)
{
PORTA=0xFF;
DDRA=0xFF;
#asm("sei") ;
while (1)
{
if(count == 0)
{
for(count=0 ; count!=255 ; count++)
{
PORTA = count ;
}
}
if(count == 255)
{
for(count=255 ; count!=0 ; count--)
{
PORTA = count ;
}
}
};
}

21. Practical No: 7 “Sine wave generation using look-up table”
Aim:
Write a program in Assembly/C programming language to alternately ON/OFF LEDs connected to
two different ports. Draw appropriate circuit diagram to demonstrate the above problem. Write
description of the above program and explain hardware and software part of above program. Draw
o/p waveform if necessary.
Softwares used:
CodeVisionAVR Software.
WAVRASM Software.
Proteus Professional 6.5 SP5 Software.
Components used:
AT90S8535 Microcontroller.
LED’s
Logic:
11. Setting a logic-high on the LSB of PORTA and logic-low on PORTB.
12. Setting a delay of 1 sec.

22. Circuit Diagram:

23. Program:
#include <90s8535.h>
int count = 9, i ;
int arrValuesHigh[] = {245, 245, 246, 246, 247, 247, 248, 248, 249, 249, 250, 250, 251, 251,
252, 252, 253, 253, 254, 254, 255, 255} ;
int arrValuesLow[] = {0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9} ;
void main(void)
{
PORTA=0xFF;
DDRA=0xFF;
while (1)
{
if(count == 9)
{
for(i=0 ; i<22 ; i++)
{
PORTA = arrValuesLow[i] ;
}
for(count=9 ; count!=245 ; count++)
{
PORTA = count ;
}
for(i=0 ; i<22 ; i++)
{
PORTA = arrValuesHigh[i] ;
}
}
if(count == 245)
{
for(i=21 ; i>=0 ; i--)
{
PORTA = arrValuesHigh[i] ;
}
for(count=245 ; count!=9 ; count--)
{
PORTA = count ;
}
for(i=21 ; i>=0 ; i--)
{
PORTA = arrValuesLow[i] ;
}
}
};}

24. Practical No: 8 - “Microcontrollers communicating over a serial link”
Aim:
Write a program in Assembly/C programming language to alternately ON/OFF LEDs connected to
two different ports. Draw appropriate circuit diagram to demonstrate the above problem. Write
description of the above program and explain hardware and software part of above program. Draw
o/p waveform if necessary.
Software’s used:
CodeVisionAVR Software.
WAVRASM Software.
Proteus Professional 6.5 SP5 Software.
Components used:
AT90S8535 Microcontroller.
LED’s
Logic:
13. Setting a logic-high on the LSB of PORTA and logic-low on PORTB.
14. Setting a delay of 1 sec.

25. Circuit Diagram:

27. Program:
//SENDER
#include <90s8535.h>
#include<delay.h>
unsigned int chout = 0x00;
void main(void)
{
PORTA=0x00;
DDRA=0xFF;
UBRR=0x33;
UCR=0x58;
while (1)
{
UDR = chout;
chout++;
if(chout==0xff)
chout=0x00;
delay_ms(100);
};
}
//RECEIVER
#include <90s8535.h>
#include<delay.h>
void main(void)
{

28. PORTA=0x00;
DDRA=0xff;
UCR=0x58;
UBRR=0x33;
while (1)
{
PORTA=UDR;
delay_ms(100);
};
}

29. Practical No: 9 “Read switch-status from i/p port and
display at o/p port”
Aim:
Write a program in Assembly/C programming language to alternately ON/OFF LEDs connected to
two different ports. Draw appropriate circuit diagram to demonstrate the above problem. Write
description of the above program and explain hardware and software part of above program. Draw
o/p waveform if necessary.
Software’s used:
CodeVisionAVR Software.
WAVRASM Software.
Proteus Professional 6.5 SP5 Software.
Components used:
AT90S8535 Microcontroller.
LED’s
Logic:
15. Setting a logic-high on the LSB of PORTA and logic-low on PORTB.
16. Setting a delay of 1 sec.

30. Circuit Diagram:

31. Program:
#include <90s8535.h>
#include<delay.h>
void main(void)
{
PORTA=0x00;
DDRA=0xff;
PORTD=0x00;
DDRD=0xff;
PORTB=0x00;
DDRB=0x00;
while (1)
{
PORTD = 0xff;
PORTA=PINB;
};
}

32. Practical No: 10 “using Input Capture Pin (ICP), measure pulse
width & display at o/p port”
Aim:
Write a program in Assembly/C programming language to alternately ON/OFF LEDs connected to
two different ports. Draw appropriate circuit diagram to demonstrate the above problem. Write
description of the above program and explain hardware and software part of above program. Draw
o/p waveform if necessary.
Software’s used:
CodeVisionAVR Software.
WAVRASM Software.
Proteus Professional 6.5 SP5 Software.
Components used:
AT90S8535 Microcontroller.
LED’s
Logic:
17. Setting a logic-high on the LSB of PORTA and logic-low on PORTB.
18. Setting a delay of 1 sec.

33. Circuit Diagram:

34. Program:
#include <90s8535.h>
#define pulse_out PORTC
#define ICP PIND.6
unsigned char ov_counter;
unsigned int rising_edge,falling_edge;
unsigned long pulse_clocks;
interrupt [TIM1_OVF]timer1_ovf_isr(void)
{
ov_counter++;
}
interrupt [TIM1_CAPT] void timer1_capt_isr(void)
{
if(ICP)
{
rising_edge=ICR1;
TCCR1B=TCCR1B &
0xBF; ov_counter=0;
}
else
{
falling_edge=ICR1;
TCCR1B=TCCR1B | 0x40;
pulse_clocks=(unsigned long)falling_edge-(unsigned
long)rising_edge+(unsigned long)ov_counter *100000;
pulse_out=pulse_clocks;
}
}
void main(void)
{
PORTA=0x00;
DDRA=0x00;
PORTB=0x00;
DDRB=0x00;
DDRC=0xff;
TCCR1B=0xc2;

35. TIMSK=0x24;
#asm("sei");
while (1)
{
};
}

36. Practical No: 11 “Working of Interrupt_0 on falling
edge”
Aim:
Write a program in Assembly/C programming language to alternately ON/OFF LEDs connected to
two different ports. Draw appropriate circuit diagram to demonstrate the above problem. Write
description of the above program and explain hardware and software part of above program. Draw
o/p waveform if necessary.
Software’s used:
CodeVisionAVR Software.
WAVRASM Software.
Proteus Professional 6.5 SP5 Software.
Components used:
AT90S8535 Microcontroller.
LED’s
Logic:
19. Setting a logic-high on the LSB of PORTA and logic-low on PORTB.
20. Setting a delay of 1 sec.

37. Circuit Diagram:

38. Program:
#include <90s8535.h>
interrupt [EXT_INT0] void ext_int0_isr(void)
{
PORTA=PORTA ^ 0x01;
}
void main(void)
{
PORTB=0x01;
DDRB=0x01;
DDRA=0x01;
GIMSK=0x40;
MCUCR=0x02;
#asm("sei");
while (1)
{
};
}