โวลต์มิเตอร์แบบดิจิตอลที่ใช้ 8051 Microcontroller
โวลต์มิเตอร์แบบดิจิตอลที่ใช้ 8051 Microcontroller
ส่วนประกอบวงจร- AT89C51 micro controller
- ADC0804 IC
- 25V Voltage Sensor
- AT89C51 programming board
- Variable resistor (to demonstrate the program)
- DC Adapter or Battery
Code
#include<reg51.h>
#define lcd P3
#define dat P2
sbit rs=P1^6;
sbit e=P1^7;
void delay (int);
void display (unsigned char);
void cmd (unsigned char);
void init (void);
void string (char *);
void intro (void);
char i=0;
void delay (int d)
{
unsigned char i=0;
for(;d>0;d--)
{
for(i=250;i>0;i--);
for(i=248;i>0;i--);
}
}
void cmd (unsigned char c)
{
lcd=c;
rs=0;
e=1;
delay(10);
e=0;
}
void display (unsigned char c)
{
lcd=c;
rs=0;
e=1;
delay(10);
e=0;
}
void display (unsigned char c)
{
lcd=c;
rs=1;
e=1;
delay(10);
e=0;
}
void string (char *c)
{
while(*c)
{
display(*c++);
}
}
void init (void)
{
cmd(0x38);
cmd(0x01);
cmd(0x0c);
cmd(0x80);
}
void intro (void)
{
string(" Electronics ");
cmd(0xc0);
string(" Hub ");
delay(2000);
cmd(0x01);
string(" Digital ");
cmd(0xc0);
string(" Voltmeter ");
delay(2000);
cmd(0x01);
cmd(0x80);
}
void main()
{
unsigned int temp=0;
unsigned int temp1=0;
float val=0.0;
init();
intro();
dat=0xff;
while(1)
{
if(i==0)
{
string(" Volts - ");
i++;
}
val=dat*0.02; // 0.02 is resolution of adc
val=val/0.2; // 0.2 is nothing but (R2/(R1+R2)) resistor values in the voltage sensor
cmd(0x89);
if((val>=1.0) && (val<10.0))
{
display(' ');
temp=val*1000;
temp1=((temp/1000)+48);
display(temp1);
display('.');
temp1=(((temp/100)%10)+48);
display(temp1);
}
else if((val>=10.0) && (val<100.0))
{
temp=val*100;
temp1=((temp/1000)+48);
display(temp1);
temp1=(((temp/100)%10)+48);
display(temp1);
display('.');
temp1=(((temp/10)%10)+48);
display(temp1);
}
else
{
display(' ');
string("0.0");
}
delay(1000);
}
while(1);
}
