Random Number Generator using 8051

Expert Engineer September 25, 2021

0 87 3 minutes read

In this project, I will demonstrate how to generate a random number using an 8051 microcontroller by explaining the circuit and operation of a Random Number Generator.

When a push button is pressed, this project creates a random number between 0 and 100. This is a simple project, and embedded projects may not have any meaningful applications. The project work is merely an example.ran

Outline

Circuit Principle of Random Number using 8051
Circuit Diagram Random Number using 8051 Microcontroller
Components Required
Circuit Design of Random Number using 8051
How to Write the Program?
CODE
Random Number Generator using 8051 – Circuit Simulation Video
How to Operate Random Number Circuit using 8051?
Random Number Generator using 8051 Circuit Applications
Random Number Generator using 8051 Project Output Video

Circuit Principle of Random Number Generator using 8051

When a button is pressed, a random number generator creates a number at random within a specified range. When the push button (which is attached to P3.0) is pressed, the LCD (liquid crystal display) displays the number at random.

The counter is rapidly advanced from 0 to 99 in this method. The LCD displays the current count value when you press the button. When the button is pressed, the 8051 Microcontroller selects a random number because the count is incrementing at a high rate.

Circuit Diagram Random Number Generator using 8051 Microcontroller

Components Required

AT89C51 (8051 Microcontroller)
8051 Programmer
Programming cable
5V Power Supply
16×2 Alphanumeric LCD
2 Ceramic Capacitors – 33pF
11.0592 MHz Crystal
Push Button – 3
Electrolytic Capacitor – 10μF, 16V
10KΩ Resistor (1/4 watt) – 2
330Ω Resistor (1/4 watt) – 2
POT – 10KΩ
1KΩ X 8 Resistor Pack
Connecting Wires

Circuit Design of Random Number Generator using 8051

The 8051 microprocessor, 162 alphanumeric LCD display, push buttons, and a few passive components are used in the circuit. The AT89C51 Microcontroller is the circuit’s key component.

Two push buttons are connected to P3.0 and P3.1 in the above circuit, with one push button (Random – P3.0) generating a random number and the second push button (RST – P3.1) resetting the count.

The LCD data pins are connected to the microcontroller’s PORT2, while the control pins RS, RW, and En are connected to P2.0, GND, and P2.1. Because the LCD is wired in 8-bit mode, we must use all of the LCD’s data pins.

The reset circuit for the 8051 microcontroller is made up of a 10K resistor, a 10F capacitor, and a push button. The oscillator for the 8051 microcontroller is provided by two 33pF capacitors and an 11.0592 MHz Quarts Crystal.

The contrast of the LCD is controlled using a 10K potentiometer linked to the VEE pin of the LCD. We can change the contrast or brightness by increasing the pot’s resistance.

NOTE: If you want to reduce the data lines of LCD, you can use 4 bit mode.

How to Write the Program?

Now let’s look at how to programme an 8051 microcontroller to generate random numbers. To begin, create a count variable of type integer and set the LCD to 8 bits. To make the programme run indefinitely, use an unlimited while loop. In this endless WHILE loop, take the value of the integer and increment it till the button is pressed (by using another while loop).

Count up to 99, then back down to 0 and repeat the process until the count reaches 100 (the upper limit). Change the value in the loop to increase the upper limit of the random number generator. The count stops when the button is pressed, and the current count value is displayed on the LCD.

If you want to increase the top limit of the random number generator in this software, you can make minor changes. Because we’re using LCD, we can boost the top limit of the random number generator, which isn’t possible if you’re using two seven-segment panels (you have to increase the number of 7-Segment displays as well).

CODE

	#include<reg51.h>
	#define lcd P0

	sbit rs=P2^0;
	sbit e=P2^1;
	sbit sw=P3^0;
	sbit rst=P3^1;

	unsigned int i=0;

	void delay (int);
	void display (unsigned char);
	void cmd (unsigned char);
	void string (char *);
	void init (void);
	void int_lcd(unsigned int);


	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(5);
	e=0;
	}

	void display (unsigned char c)
	{
	lcd=c;
	rs=1;
	e=1;
	delay(5);
	e=0;
	}
	void string (char *p)
	{
	while(*p)
	{
	display(*p++);
	}
	}

	void init (void)
	{
	cmd(0x38);
	cmd(0x0c);
	cmd(0x01);
	cmd(0x80);
	}

	void int_lcd(unsigned int n)
	{
	char a[4]={0},i=0;
	if(n==0)
	{
	display(‘0’);
	return;
	}
	else
	{
	while(n>0)
	{
	a[i++]=(n%10)+48;
	n/=10;
	}
	for(–i;i>=0;i–)
	{
	display(a[i]);
	}
	}
	}

	void main()
	{
	sw=1;
	rst=1;
	init();
	cmd(0x80);
	string(” Random Number “);
	cmd(0xc0);
	string(” Generator “);
	delay(2000);
	cmd(0x01);
	while(1)
	{
	cmd(0x80);
	string(“Press the button”);
	while(sw!=0)
	{
	i=++i;
	if(i==100)
	i=0;
	}
	cmd(0x80);
	string(“RAND NUM: “);
	cmd(0x8a);
	int_lcd(i);
	while(rst!=0);
	//cmd(0x01);
	}
	}