Digital DC voltmeter using
Microcontroller or microprocessor is a project in which basically voltage of
the system or circuit is measure and 7-segment or display on 16x2 Alpha numeric
LCD(Liquid crystal display) This project is best suited for learning of voltage
measurement and microcontroller or microprocessor based system from electronics
or electrical field person or engineering or diploma student. In this project
we are using digital measurement method in which we are uses ADC (Analog to
digital convertor) to measure digital form of voltage and then processes this
digital value using microprocessor or microcontroller 8051 from Atmel(89s52)
then display this digital value on 7-segment or 16x2 Alpha numeric LCD. we can
also use other microcontroller or microprocessor manufactures by NXP ARM,
Microchip’s PIC18f,PIC12F,PIC16F series…etc.,
STM series from STMicrotronics , freescale ,AVR etc. instated of Atmel 8051.Some
of Microcontroller have inbuilt ADC Analog to digital converter .We are also
provided or tested on computer simulation using simulation software Proteus.
 |
| Proteus Simulation-Digital DC voltmeter Using Microcontroller 8051(Atmel 89x52) |
Aim:
Design Digital
voltmeter using microcontroller or microprocessor and display on 7-segment or
16x2 LCD(Liquid crystal display)we are using 7-segment in this simulation in
Proteus.
Theory:
This introduction makes the link with analog voltage
measurement. The digital voltmeters are simply compute digital values from ADC
then processed and display on 7 segment.
A key element in processing digital signals is
microcontroller. Microcontroller perform direct Manipulations signals. To
completely describe digital voltmeter, three basic elements (or building
blocks) are needed: an ADC(analog to digital converter 0808), a
microcontroller, and a display device. The ADC 0808 has 10 inputs channels and
8-bit digital output
Software:
Keil uvision 3 3.30a
C51 8051 Compiler
Proteus 7.10 Labcenter Electronics
Component and Hardware:
AT89S52 Microcontroller from Atmel
ADC0808 Analog to Digital Converter
8-channel 8-bit Texas Instruments
7-segment Multiples Display
C Code(C Programme):
//*******************************************************
// *******
DC voltmeter ********
//*******************************************************
//Company : www.beprojectidea.blogspot.com
//Controller:
8051 Microcontroller ATMEL
// Compiler
: C51 Keil uvision 3 3.30a
//Version
: 1.0
//*******************************************************
#include
<AT89X52.H>
#define
data_point P0 //data bus port
/*
ADC0809 control pins */
sbit
EOC =P2^0;
sbit
ADDA =P2^1;
sbit
ADDB =P2^2;
sbit
ADDC =P2^3;
sbit
OE =P2^5;
sbit
START=P2^6;
sbit
CLK =P2^7;
/*
Global variables */
unsigned
char disp[3]={0,0,0};
unsigned
char t0count=0;
/*
Display function */
void
display()
{
unsigned char i,j,k=0x80;
for(i=0;i<3;i++)
{
P1=~0;
P3=disp[i];
P1=~k;
k>>=1;
for(j=200;j>0;j--);
}
P1=~0;
}
/*Function
to Read ADC*/
unsigned
char ADC0809()
{
unsigned char d;
ADDC=0;
ADDB=0;
ADDA=0;
TR1=1;//enable
timer
START=1; START=0; //start ADC
while(EOC==0); //check for EOC to go high
OE=1; //enable output data
d=data_point; //read data
OE=0; //disable adc
TR1=1;//stop timer
return
d; //return data
}
void
covert(unsigned char x)
{
char
code dispcode[]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F};
disp[0]=dispcode[x/50];
disp[0]=disp[0]+0x80;
x=(x%50)*2;
disp[1]=dispcode[x/10]; //first decimal
disp[2]=dispcode[x%10]; // second decimal
}
void
main()
{
TMOD=0X21; //Enable timer 0 in mode 1 and
timer 1 in momde 2
TH0=(65536-10000)/256; //T0 for 10ms
TL0=(65536-10000)%256;
TH1=256-2; // T1 for 2us
ET0=1;
ET1=1;
EA=1;
TR0=1;
OE=0;
//Initilize ADC
START=0;
EOC=1;
while(1)
{
display();
//display data
}
}
void
time0() interrupt 1
{
TH0=(65536-10000)/256;
TL0=(65536-10000)%256;
t0count++;
if (t0count==10) //check for
1sec
{
t0count=0;
covert(ADC0809()); //´convert data
from adc
}
}
void
time1() interrupt 3
{
CLK=~CLK; //ADC clock pulse
}
CONCLUSION
We can
measure voltage using digital voltmeter Using Microcontroller 8051(Atmel 89x52) and compare with the analog voltmeter reading
which almost accurate and we can further develop other meter in future such as ohmmeter,
ammeter etc.we can
also use other microcontroller or microprocessor manufactures by NXP ARM,
Microchip’s PIC18f,PIC12F,PIC16F series…etc.,
STM series from STMicrotronics , freescale ,AVR etc. instated of Atmel 8051.Some
of Microcontroller have inbuilt ADC Analog to digital converter.
( Full Report)DOWNLOAD
(C Code and Computer Simulation) DOWNLOAD
