a brief description of 8051 microcontroller
DESCRIPTION
“Heaven’s Light is our Guide” Rajshahi University of Engineering and Technology Department of Electrical and Electronic Engineering. A brief description of 8051 Microcontroller. By MD. MOSHIUL ALAM (JONY) ROLL NO. 041016 EEE - 4/7, RUET . Mobile No. +8801710998670 - PowerPoint PPT PresentationTRANSCRIPT
“HEAVEN’S LIGHT IS OUR GUIDE”
RAJSHAHI UNIVERSITY OF ENGINEERING AND TECHNOLOGY DEPARTMENT OF ELECTRICAL AND ELECTRONIC ENGINEERING
A BRIEF DESCRIPTION OF
8051 MICROCONTROLLE
R
By MD. MOSHIUL ALAM (JONY)ROLL NO. 041016EEE - 4/7, RUET.Mobile No. +8801710998670E-mail:[email protected]
WHAT IS A MICROCONTROLLER?
Simply say, it is a small computer.We know that a
computer is a machine which is
used for mathematical and logical operation.
It consists of various components such as a
microprocessor, a RAM, ROM, Hard disk, various peripheral devices. All
the devices are set up in a broad named as
motherboard.
Where as a microcontroller is a single chip which
include all the things of a
computer but limited number of
capacity.
IS THEIR ANY SIMILARITY BETWEEN A MICROPROCESSOR AND A MICROCONTROLLER
No there is not.A microprocessor is a part of the microcontroller.
A microprocessor can’t operate without RAM, ROM and other peripheral devices.
CONSIDER A MICROCONTROLLER OF ATMEL, AT89C51ED2
Features Compatible with MCS-51 Products4K Bytes of In-System Reprogrammable Flash MemoryFully Static Operation: 0 Hz to 24 MHzThree-level Program Memory Lock128 x 8-bit Internal RAM32 Programmable I/O LinesTwo 16-bit Timer/CountersSix Interrupt SourcesProgrammable Serial ChannelLow-power Idle and Power-down Modes40-pin DIP
Pin Description1 – 8 P1.0 – P1.7 – Port 1
9 RST – Reset10 – 17
P3.0 – P3.7 – Port 3
18 XTAL2 – Crystal19 XTAL1 – Crystal20 GND - Ground
21 – 28
P2.0 – P2.7 – Port 2
29 PSEN – Program Store Enable
30 ALE – Address Latch Enable31 EA – External Access Enable
32 – 39
P0.7 – P0.0 – Port 0
40 Vcc - Positive Power Supply
NOW TO OPERATE THE CHIP AS A MICROCONTROLLER WE HAVE TO WRITE A C++ PROGRAM. VARIOUS COMPANY RELEASE THEIR OWN C COMPILLER.
In our project we used the
Keil Compiler.First we write the program and run it on
Keil and check that any error is
their. Keil converts the C program to Hex file
because MC recognize only
Machine Language.If there is no error then we burn it to the
Chip via RS232 Connector.
TO PERFORM THE TASK, THE MC NEED A SPECIFIC FREQUENCY
The frequency is generally high such as
12MHZ
This frequency is applied to the 18 & 19
pins.
The MC divides the supply frequency by
12.
For various mathematical and logical operation MC needs
certain no. of execution cycle.
It always operate on 5V. Only recognizes 0 (0V)
and 1 (5V).
NOW CONSIDER A PRACTICAL PROBLEM FOR THE USE OF OUR MICROCONTROLLER
Suppose we want to automate the light of our house. If the natural light is reduces then the microcontroller switch on the light.The light sensor can be done by using the LDR (Light dependent resistor)
HERE IS THE A SIMPLE CIRCUIT FOR THE LIGHT SENSOR:
The above circuit is a light sensor. When light intensity is low then LDR provide about 10K resistance thus the voltage at pin 2 is low ( 4.7*5/(10+4.7)=1.6 and the voltage at the pin 3 (2.5V) is high since the
constant voltage is supplied to the two voltage dividing path. Thus we get 5V at the output. Similarly
when there is sufficient light then the LDR provide about 3K resistance and the voltage at pin 2 is high
then the pin 3. Thus output is 0V. (5*4.7/(3+4.7))=3.05
NOW IF WE CONNECT THE PREVIOUS CIRCUIT OUTPUT TO P1.1 PORT AND THE LIGHT SWITCH IS CONTROLLED BY THE MOSFET WHOSE GATE IS CONNECTED TO THE P2.1 AND WRITING THE FOLLOWING PROGRAM :
#include <reg51.h> //Header file declaration for 8051 mcsbit sensor=P1.2; //single bit declaration of P1 portsbit light=P2.1; //single bit declaration of P2 portVoid main(void){
while(1) //infinite loop declaration{if(sensor==1)light=1;elselight=0;}
}
Here is the actual circuit
8051 MC
N.B . To operate the above circuit, ISP(in system programming) board is requied.
MY BELIEFS
Always thought positive. Never, never and never take
negative as a reference.A Candle don’t loose its light by spreading
its light farther.A man always learn through
mistakes.Every man should believe in his region and the life which comes
after the death.How you can believe that a tiny electron pass through a wire if you don’t believe your creator.
Because both are not seen.
THANKS YOU