Line follower robot using 8051 Line follower robots were one of the earliest automatic guided robots. They are able to follow a line marked on a contrasting background, usually a black line on a white surface or a white line on a black surface. Usually, the line follower robot works on a closed loop feedback […]
Interfacing dot matrix LED display to 8051 microcontroller. LED dot matrix display. An LED dot matrix display consists of a matrix of  LED’s arranged in a rectangular configuration. The desired character or graphics can be displayed by switching ON /OFF  a desired configuration of LED’s. Common display configurations available are 7×5, 8×8, 7×15, etc. LED
Object counter using 8051 microcontroller. This article is about a simple object counter/visitor counter using 8051 microcontroller . AT89S51 belonging to the 8051 family is the microcontroller used here. This circuit can count the number of objects passing across a line , number of persons passing through a gate/door and so on. The can be
We all see Police using breathalyzers on drivers to check if they are under the influence of alcohol. Drink & driving is a crime in all countries. But do you know that this machine is easy to make? Here is how to DIY alcohol breathalyzer with 3 digit display output. Alcohol Breathalyzer circuit using 8051
This article is about a simple heart rate monitor using 8051 microcontroller. Like the previous 8051 projects, AT89S51 is the microcontroller used here. The device senses the heart rate from the finger tip using IR reflection method and displays it on a three digit seven segment display in beats per minute. The circuit has an
This article is about interfacing a hex key pad to 8051 microcontroller. A clear knowledge on interfacing hex key pad to 8051 is  very essential  while designing embedded system projects which requires character or numeric input or both. For example projects like digital code lock, numeric calculator etc. Before going to the interfacing in detail,
This article is a compilation of all 8051 based Electronic Projects and Circuits we have developed at CircuitsToday till date. We have one of the biggest collection of 8051 based Projects – which range from very Advanced one’s like Electronic Voting Machine, Heart Rate Monitor, RFID based Access Control (and a lot more) to Medium
Ultrasonic range finder using 8051 . A simple ultrasonic range finder using 8051 microcontroller is presented in this article. This ultrasonic rangefinder can measure distances up to  2.5 meters at an accuracy of 1 centi meter. AT89s51 microcontroller and the ultrasonic transducer module HC-SR04 forms the basis of this circuit. The ultrasonic module sends a
Contactless digital tachometer using 8051. A three digit contact less digital tachometer using 8051 microcontroller which can be used for measuring the revolutions/second of a rotating wheel, disc, shaft or anything like that is introduced in this project. The tachometer  can measure up to a maximum of 255 rev/sec at an accuracy of 1 rev/sec.
PWM lamp dimmer. A simple and efficient PWM lamp dimmer using timer IC NE555 is discussed in this article. Yesterdays linear regulator based dimmers can only attain a maximum efficiency  of 50% and are far inferior when compared to the PWM based dimmers which can hit well over 90% efficiency. Since less amount of power
Delay using 8051 timer. The 8051 microcontroller has two independent 16 bit up counting timers named Timer 0 and Timer 1 and this article is about generating time delays using the 8051 timers. Generating delay using pure software loops have been already discussed here but such delays are poor in accuracy and cannot be used
Software delay routine in 8051 In an 8051 microcontroller, it requires 12 cycles of the processor clock for executing a single instruction cycle. For an 8051 microcontroller clocked by a 12MHz crystal, the time taken for executing one instruction cycle is 1µS and it is according to the equation, Time for 1 instruction cycle= 12
DIY Random number generator A Â random number generator using 8051 that displays a random number between 0 & 99 is shown in this article. The circuit itself is very simple and may not find any applications in serious embedded projects and this article is just an illustration. The circuit is based on AT89S51 microcontroller, two
Thermometer using 8051. This article is about a simple 0-100°C digital thermometer with 1°C resolution using 8051. The circuit is based on LM35 analog temperature sensor, ADC0804 and AT89S51 microcontroller. LM35 is an analogue temperature sensor IC which can measure a temperature range of -55 to 150°C. Its output voltage varies 10mV per °C change in
Voltmeter using 8051. A simple 0-5V voltmeter using 8051 is shown in this article. This digital voltmeter has a sensitivity of 200mV which is a bit low but this project is meant for demonstrating how an ADC and seven segment display can be interfaced to 8051 to obtain a digital readout of the input voltage.
ADC (Analog to digital converter) forms a very essential part in many embedded projects and this article is about interfacing an ADC to 8051 embedded controller. ADC 0804 is the ADC used here and before going through the interfacing procedure, we must neatly understand how the ADC 0804 works. ADC 0804. ADC0804 is an 8 bit
Water level controller using 8051. A water level controller using 8051 is shown in this article. A lot of water level controller projects have been published in this website but this is the first one based on a microcontroller. This water level controller monitors the level of the over head tank  and automatically switches on
This article shows how to interface a DC motor to an 8051 microcontroller. Interfacing DC motor to 8051 forms an essential part in designing embedded robotic projects. A well designed 8051-DC motor system has essentially two parts. Firstly an 8051 with the required software to control the motor and secondly a suitable driver circuit. Most of
A Note about 7 segment LED display. This article is about how to interface a seven segment LED display to an 8051 microcontroller. 7 segment LED display is very popular and it can display digits from 0 to 9 and quite a few characters like A, b, C, ., H, E, e, F, n, o,t,u,y,
This article is all about how to interface push button switches to an 8051 microcontroller. Push button switches are widely used in embedded system projects and the knowledge about interfacing them to 8051 is very essential in designing such projects. A typical push button switch has two active terminals that are normally open and these
LCD display is an inevitable part in almost all embedded projects and this article is about interfacing a 16×2 LCD with 8051 microcontroller. Many guys find it hard to interface LCD module with the 8051 but the fact is that if you learn it properly, its a very easy job and by knowing it you
6 function 8 channel light chaser using 8051. A 6 function 8 channel light chaser using 8051 is shown here. The hardware and software of this circuit are very simple and the light functions gets repeated one after another automatically. P1.0 to P1.7 of the microcontroller (AT89S51) are assigned as the output pins. Corresponding LEDs
Blinking 1 LED using 8051 This is the first project regarding 8051 and of course one of the simplest, blinking LED using 8051. The microcontroller used here is AT89S51 In the circuit, push button switch S1, capacitor C3 and resistor R3 forms the reset circuitry. When S1 is pressed, voltage at the reset pin (pin9)
In this guide, let’s learn in detail about Push Pull Amplifiers. We’ve covered theory and applications behind a push pull amplifier. We’ve also demonstrated different types of push pull amplifiers, like Class A, Class B and Class AB push pull amplifier models. A push pull amplifier is an amplifier which has an output stage that
Half adder circuit. To understand what is a half adder you need to know what is an adder first. Adder circuit is a combinational digital circuit that is used for adding two numbers. A typical adder circuit produces a sum bit (denoted by S) and a carry bit (denoted by C) as the output. Typically
