Innovative Projects with the 8051 Microcontroller

Posted on May 6, 2025 in Computers

Time Delay Generation with 8051 Microcontroller

#include 
sbit FREQ = P2^3;

void timerDelay() {
    TH1 = 0xDC; // Load the timer value
    TL1 = 0x00;
    TR1 = 1; // Turn ON Timer zero
    while (TF1 == 0); // Wait for Timer Overflow
    TF1 = 0; // Clear the timer overflow flag
    TR1 = 0;
}

void main() {
    TMOD = 0x10; // Timer0 mode 1
    while (1) {
        FREQ = 1;
        timerDelay();
        FREQ = 0;
        timerDelay();
    }
}

Relay Interfacing with 8051 Microcontroller

#include 
sbit relay_pin = P2^0;
sbit SW = P1^0;

void Delay(int k) {
    int j;
    int i;
    for (i = 0; i < k; i++) {
        for (j = 0; j < 100; j++);
    }
}

void main() {
    SW = 1;
    while (1) {
        if (SW == 0) {
            relay_pin = 0; // Relay OFF
            Delay(1000); // 1 sec delay
        }
        if (SW == 1) {
            relay_pin = 1; // Relay ON
            Delay(1000); // 1 sec delay
        }
    }
}

LED Interfacing with 8051 Microcontroller

#include // Special function register declarations
// for the intended 8051 derivative
sbit LED = P1^0; // Defining LED pin

void Delay(void); // Function prototype declaration

void main(void) {
    while (1) { // Infinite loop
        LED = 0; // LED ON
        Delay();
        LED = 1; // LED OFF
        Delay();
    }
}

void Delay(void) {
    int j;
    int i;
    for (i = 0; i < 10; i++) {
        for (j = 0; j < 10000; j++);
    }
}

Seven Segment Display Interfacing with 8051 Microcontroller

#include 
void DELAY_ms(unsigned int ms_Count);

void main() {
    char Display[] = {0x3F, 0x06, 0x5B, 0x4F, 0x66, 0x6D, 0x7D, 0x07, 0x7F, 0x6F};
    int i;
    while (1) {
        for (i = 0; i <= 9; i++) { // Loop to display 0-9
            P2 = Display[i];
            DELAY_ms(1000);
        }
    }
}

void DELAY_ms(unsigned int ms_Count) {
    unsigned int i, j;
    for (i = 0; i < ms_Count; i++) {
        for (j = 0; j < 100; j++);
    }
}

LCD Interfacing with 8051 Microcontroller

#include 
sbit rs = P2^0; // RS pin connected to pin 2 of port 3
sbit rw = P2^1; // RW pin connected to pin 3 of port 3
sbit e = P2^2; // E pin connected to pin 4 of port 3

void msdelay(unsigned int time) { // Function for creating delay in milliseconds.
    unsigned i, j;
    for (i = 0; i < time; i++)
        for (j = 0; j < 1275; j++);
}

void lcd_cmd(unsigned char command) { // Function to send command instruction to LCD
    P1 = command;
    rs = 0;
    rw = 0;
    e = 1;
    msdelay(1);
}

void lcd_data(unsigned char disp_data) { // Function to display data on LCD
    P1 = disp_data;
    rs = 1;
    rw = 0;
    e = 1;
    msdelay(1);
}

ADC Interface

#include 
#define input P1 // Input port (read values of ADC)
#define output P3 // Output port (connected to LEDs)

void delay(unsigned int msec);
void adc();
sbit rd = P2^5; // Write pin.
sbit wr = P2^6; // Read pin.
sbit intr = P2^7; // Interrupt pin.

void main() {
    input = 0xFF; // Declare port 1 as input port.
    output = 0x00; // Declare port 0 as output port.
    while (1) {
        adc();
    }
}

void delay(unsigned int msec) { // Delay function
    int i, j;
    for (i = 0; i < msec; i++)
        for (j = 0; j < 1275; j++);
}

void adc() { // Reading values from ADC and display on the LEDs
    rd = 1;
    wr = 0;
    delay(10);
    wr = 1;
    while (intr == 1);
    rd = 0;
    output = input;
    delay(10);
    intr = 1;
}

Stepper Motor Interfacing with 8051 Microcontroller

#include 
void delay(void);

void main() {
    while (1) {
        P1 = 0x06;
        delay();
        P1 = 0x03;
        delay();
        P1 = 0x09;
        delay();
        P1 = 0x0C;
        delay();
    }
}

void delay(void) {
    unsigned char cnt, cnt1;
    for (cnt = 0; cnt <= 254; cnt++)
        for (cnt1 = 0; cnt1 < 254; cnt1++);
}

DC Motor Interfacing with 8051 Microcontroller

#include 
sbit in1 = P2^0;
sbit in2 = P2^1;
sbit en1 = P2^2;
sbit en2 = P2^3;
sbit in3 = P2^4;
sbit in4 = P2^5;

void forward();
void reverse();

void main() {
    en1 = 1;
    en2 = 1;
    while (1) {
        forward();
        reverse();
    }
}

void forward() {
    in1 = 1;
    in2 = 0;
}

void reverse() {
    in4 = 1;
    in3 = 0;
}