RGB LED Fading with Arduino

In this tutorial an RGB LED is interfaced with Arduino Uno and then it is used to fade the LEDs of different colors one by one.

In fact there are two different types of RGB LEDs - common cathode type (common negative) and common anode type (common positive). In CC (Common Cathode or Common Negative), there will be three positive terminals each terminal representing a color and one negative terminal representing all three colors. The internal circuit of a CC RGB LED can be represented as below.

Here you can see the demonstration video of fading RGB LEDs:

See here the full project: Arduino RGB LED Tutorial

Emergency Light Circuit

In this emergency light circuit, when the Power goes OFF, the emergency light activates automatically. We have used four bright white LEDs, more LEDs can be added to produce more light considering that total current consumption should not exceed the supply current. Ultra bright white LED consumes 3v and 20mA current.

See here the full article with circuit diagram: emergency light circuit

Latest Electronics Projects and Circuits

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  RFID Based Attendance System using 8051

  In this RFID based Attendance System project, we will explain you how can we count attendance automatically by using RFID cards. RFID Tecnology (Radio Frequency Identification and Detection) is commonly used in schools, colleges, office and stations for various purposes to automatically keep a track of people.  Here we will count the attendance of an authorised person by using RFID.

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  Fire Alarm System using AVR

  In this project, we are going to make a Fire Alert System using ATMEGA8 microcontroller and fire sensor. Fire sensor can be of any type, however we are using IR (Infrared) based Fire Sensor. Although IR based Fire Sensors have some disadvantages mostly of inaccuracy, it is the cheapest and easiest way to detect fire.
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  Digital Code Lock using Arduino

  Security is a major concern in our day to day life, and digital locks have became an important part of these security systems. One such digital code lock is imitated in this project using arduino board and a matrix keypad. 
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  Remote Controlled Light Switch

  IR LED emits infrared light, and used in TV remotes. This Infrared is received by the receiver TSOP17XX (TSOP 1738used in TV). TSOP17XX receives the modulated Infrared waves and changes its output. TSOP is available in many frequency ranges like TSOP1730, TSOP1738, TSOP1740 etc. Last two digits represent the frequency (in Khz) of modulated IR rays, on which TSOP responds. Like for example TSOP1738 reacts when it receives the IR radiation modulated at 38Khz. TSOP output is active low, means it becomes LOW when IR is detected.
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  Color Detector using Arduino

  In this project we are going to interface TCS320 color sensor with Arduino UNO. TCS320 is a color sensor which can detect any number of colors with right programming. TCS230 contains RGB (Red Green Blue) arrays. As shown in figure on microscopic level one can see the square boxes inside the eye on sensor. These square boxes are arrays of RGB matrix. Each of these boxes contain Three sensors, One is for sensing RED light intensity, One is for sensing GREEN light intensity and the last in for sensing BLUE light intensity.
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  Arduino Based Digital Clock with Alarm

  This Arduino based Real time clock is a digital clock to display real time using a RTC IC DS1307which works on I2C protocol. Real time clock means it runs even after power failure. When power is reconnected, it displays the real time inrespective to the time and duration it was in off state. In this project we have used a 16x2 LCD module to display the time in - (hour, minute, seconds, date, month and year) format.
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  Light Intensity Measurement using LDR and AVR Microcontroller

  In this project we are going to interface LDR with ATMEGA8 microcontroller, and with this we can measure LIGHT INTENSITY in the area. In ATMEGA8, we are going to use 10bit ADC (Analog to Digital Conversion) feature to measure the light intensity.
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  100mA Ammeter using AVR Microcontroller

  In this project we are going to make a low range ammeter using ATMEGA8 microcontroller. In ATMEGA8, we are going use 10bit ADC (Analog to Digital Conversion) feature to do this. Although we have few other ways to get the current parameter from a circuit, we are going to use resistive drop method, because it’s the easiest and simplest way to get current parameter.
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  UART Communication Between Two ATmega8 Microcontrollers

  In this tutorial we are going to establish a serial communication between two ATMEGA8 microcontrollers. The communication established here is UART (Universal Asynchronous Receiver Transmitter) type. By this serial communication data can be shared between two microcontrollers, which is required in various embedded systems.
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  Line Follower Robot using 8051 Microcontroller

  Line follower Robot is a machine which follows a line, it may be a black line or a white line. Basically two types of line follower robots are: one is black line follower which follows black line and second one is white line follower which follows white line. Line follower actually senses the line and run over it. In our previous projects, we have made a black line follower robot using arduino but this time we are going to make white line follower using 8051 microcontroller. In this tutorial, we will also cover how to make a printed circuit board for line follower robot at home in low price. 

Check more interesting projects and circuits here: Electronics Projects

DIY RGB Bulb

We are building here a RGB bulb using Red, Green and Blue LEDs, we just need to add a mechanism to control the brightness or intensity of these light individually. To control the brightness, we are using PWM (Pulse width Modulation) method with 555 time IC. 555 timer IC can generate a pulse of variable width, and width of Pulse can control the Duty cycle. Duty cycle is nothing but the Ratio of High time to the total time.

Duty Cycle %= Turn ON time/ (Turn ON time + Turn OFF time) *100

See here the circuit diagram and detailed explanation

Check out the demonstration video here:

Find here more Electronic Circuits 

Arduino LED Chaser using Rotary Encoder

In this project we have interfaced a ROTARY ENCODER with ARDUINO Uno and developed a LED chaser circuit which is controlled by the rotary encoder. 

A ROTARY ENCODER is used to know the position of movement and angular movement of a motor or axis. It’s a three terminal device usually, with power and ground pins there are total 5 terminals.

Check out the demonstration video on youtube:  

For the complete project with circuit diagram and code, visit: Arduino LED Chaser Project

Explore more such interesting arduino projects here

Simple Audio Amplifier Circuit using IC LM386

Simple Mic audio amplifier can amplify sound that is given from Microphone. This circuit can be used as “Small mic and loudspeaker system” for a small space like a room. This circuit can also be used in many applications like portable music players, intercoms, radio amplifiers, TV sound systems, Ultrasonic drivers etc. It can also be used as sound sensor for microcontrollers. It is inexpensive, low power operated and only need few components to work. This circuit is based on LM386 IC to amplify sound.

Here is the demonstration video:

Find here the circuit diagram and explanation of this simple LM386 audio amplifier circuit

For more electronic circuits, visit Circuit Digest

Easy Electronic Circuits and Projects

Laser Based Security Alarm Circuit

In this laser security alarm circuit , [Saddam] has used LM358 Dual Comparator IC for comparing voltages coming from LDR. Comparator is configured as Non-inverting mode and one 10K potentiometer is connected at its non-inverting terminal. An LDR is used for detecting light or laser light with respect to ground through a 10K resistor. And the midpoint of LDR and resistor is directly connected to inverting terminal of comparator.  A red LED is connected at output pin of comparator for indicating intruder detection. A mono-stable multi-vibrator is also used for activating buzzer and LED for a time period

Day and Night Indicator

In this day and night indicator project, [Saddam] has made a circuit which will indicate if there is a dark or light in the surroundings. Some applications of this circuit, are street light controlling, home/office light controlling, day and night indicators, etc. Check out the complete post on above link.

Dancing LED Circuit

This Dancing LED circuit is used for decorative purpose and looks very good when these LEDs glow in sequential manner. We can create many kind of Dancing LEDs patterns for decoration. In this particular circuit, we have created a pattern in which 6 LEDs are illuminating in forward and reverse order. To create this circuit we have mainly used 555 timer IC and 4017 IC.

LED Chaser Circuit

You may have seen different kinds of decoration lighting patterns. In this LED chaser circuit, [Saddam] have created an interesting LED blinking pattern by using a 555 timer IC and Decade Counter IC CD 4017.

Remote Controlled Light Switch

In this remote controlled switch circuit, [Jayant] have used a TV remote to ON/OFF the AC light by pressing any button of remote, and using the TSOP1738 at receiver end. Receiver circuit is connected to AC appliance via Relay, so that we can control the light remotely. We have used IC 4017 to convert it into a push ON, push OFF switch.

Demonstration of Logic Gates

NOT Gate

NOT gates are simply inverters. They simply invert the input logic for the output. Here we are going to use 74LS04 IC for demonstration. This IC has 6 NOT gates in it. These SIX gate are connected internally.

Here is the breadboard image of a NOT gate circuit.

You can find the explanation of this circuit: NOT Gate Circuit

NAND Gate

This gate is mainly used in applications where there is a need for mathematical calculations. So calculators, computers and many digital applications use this gate. 

Here you can find the circuit diagram and detailed explanation of this Circuit: NAND Gate

XOR Gate

This gate is mainly used in applications where there is a need for mathematical calculations. So in calculators, computers and many digital applications use this gate.

Here we are going to use 74LS86 IC for demonstration, this chip has 4 EX-OR gates in it.

Here is the detailed explanation of XOR Gate Circuit

Reverse Car Parking Aid - Circuit Diagram

This reverse car parking assistant can protect your car from any damage while reverse parking. Though modern cars incorporate various reverse car parking sensors and cameras, this hobby circuit could be interesting and handy for many of us. It indicates the distance of car from any object and raise an alarm when it reaches close to the wall or the object and needs to be stopped. .

Here are the quick easy steps and a detailed explanation to understand the concepts and working of this circuit.

Go: Reverse car parking circuit

Battery Monitor Circuit Diagram

Sometimes we face a common problem when making any project related to battery or power supply - we don’t know about battery is charged or discharged. To test battery there is one common method which is using voltmeter that is available in the Multimeters. But here we have developed this battery monitor circuit to test the battery charging status. In this circuit we can easily test batteries by connecting it with the circuit. Here some LEDs are used for showing battery status.

Check out more details here: Battery Monitor Circuit

Basic tutorials to get started with arduino

Here are few basic arduino tutorials to learn working with the board.
1. How to blink an LED with Arduino:

ARDUINO UNO is an ATMEGA controller based board designed for electronic engineers and hobbyists. Arduino based program development environment is an easy way to write the program when compared to other environment development programs. Check out the tutorial to learn how to blink an LED with arduino uno board.

2. How to Use ADC in Arduino:  

In this tutorial we are introducing concept of ADC (Analog to Digital Conversion) in ARDUINO UNO. Arduino board has six ADC channels, as show in figure below. Among those any one or all of them can be used as inputs for analog voltage. The Arduino Uno ADC is of 10 bit resolution (so the integer values from (0-(2^10) 1023)). This means that it will map input voltages between 0 and 5 volts into integer values between 0 and 1023. So for every (5/1024= 4.9mV) per unit.

3.  7 Segment Display Interfacing with Arduino:

In this tutorial we are going to interface a seven segment display to ARDUINO UNO. The display counts from 0-9 and resets itself to zero.

4. Interfacing 16x2 LCD with Arduino Uno:

In this tutorial we are going to interface a 16x2 LCD with ARDUINO UNO. Unlike normal development boards interfacing a LCD to a ARDUINO is quite easy. Here we don’t have to worry about data sending and receiving. We just have to define the pin numbers and it will be ready to display data on LCD.

5. Using Shift Register with Arduino:

Now for some applications we need more than 30 pins, say if we want to design a 5x5x5 LED CUBE, so for this we need 5x5+5=30pins. For such cases we use serial to parallel converter chips or shift register. A shift register chip takes data from UNO board serially and gives output in 8 bit parallel configuration.

6. Understanding PWM Concept in Arduino Uno:

Arduino UNO has 6PWM channels, so we can get PWM (variable voltage) at any of these six pins. In this chapter we are going to use PIN3 as PWM output.

7. How to Interface a DC Motor with Arduino Uno: 

Here we are going to interface a DC motor to Arduino UNO and its speed is controlled. This is done by PWM (Pulse Width Modulation). This feature is enabled in UNO to get variable voltage over constant voltage.

For more such basic arduino tutorials and interesting projects, visit circuitdigest.com

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Automatic Fan Speed Control according to Temperature

In this arduino based project, we are going to control DC fan speed according to the room temperature and show these parameter changes on a 16x2 LCD display. It is accomplished by the data communications between Arduino, LCD, DHT11 sensor Module and DC fan that is controlled by using PWM.

Video:

See the complete project here: http://circuitdigest.com/microcontroller-projects/automatic-temperature-controlled-fan-project 

Accelerometer Based Gesture Controlled Robot

Robots are playing an important role in automation across all the sectors like construction, military, medical, manufacturing, etc. After making some basic robots like line follower robot, computer controlled robot, etc, we have developed this accelerometer based gesture controlled robot by using arduino uno. In this project we have used hand motion to drive the robot. For this purpose we have used accelerometer which works on acceleration.

Find here the complete project: Accelerometer Based Gesture Controlled Robot 

Getting Started with Arduino - Blink An LED with Arduino Uno Board

Arduino is an open-source hardware and software development board based on AVR series of microcontrollers. The project is based on a family of microcontroller board designs manufactured primarily by Smart Projects in Italy, and also by several other vendors, using various 8-bit Atmel AVR microcontrollers or 32-bit Atmel ARM processors. These systems provide sets of digital and analog I/O pins that can be interfaced to various expansion boards ("shields") and other circuits. The boards feature serial communications interfaces, including USB on some models, for loading programs from personal computers. For programming the microcontrollers, the Arduino platform provides an integrated development environment (IDE) based on the Processing project, which includes support for C and C++ programming languages.


Arduino Uno is one of the easiest to work among several arduino development boards. Here is a tutorial to get started and blink an LED with Arduino.

Here is an awesome video to get started with arduino:


You can find the simple code required to blink an external LED with Arduino Uno here.

Check Your Reaction Time By This DIY Game Circuit

Reaction timer is a game to test how fast you reacts. This game which we have developed using 555 IC is for two players where first player starts the game by pressing start button. As soon as the START button is pressed, 7 segment display starts displaying 0 to 9 numbers in a high speed. Then other player stops the counting by pressing the STOP button. As the frequency of displaying numbers is very high, it is difficult and needs full attention to react on the correct time.  Watch the video below to see demonstration of this reaction timer game.

A Johnson Counter IC 4026 is used along with 555 IC. If you are well aware of 555 timer IC and its working, you can easily understand it and build it by yourself. Here is the detailed tutorial with circuit diagram:
http://circuitdigest.com/electronic-circuits/reaction-timer-game-using-ic-555

Latest Arduino Based Mini Projects

Here are some interesting and easy arduino based projects:

1. Digital Thermometer
Thermometers are useful apparatus being used since long time for temperature measurement. In this project we have made an Arduino based digital thermometer to display the current ambient temperature and temperature changes on a LCD unit in real time.


2. Line Follower Robot
Line follower Robot is a machine which follows a line, either a black line or white line. Basically there are two types of line follower robots: one is black line follower which follows black line and second is white line follower which follows white line. Line follower actually senses the line and run over it.


3. Digital Alarm Clock
This Arduino based Real time clock is a digital clock to display real time using a RTC IC DS1307 which works on I2C protocol. Real time clock means it runs even after power failure. When power is reconnected, it displays the real time inrespective to the time and duration it was in off state.

4. Digital Tachometer
Tachometer is a RPM counter which counts the no. of rotation per minute. There are two types of tachometer one mechanical and other one is digital. Here we are going to design an Arduino based digital tachometer using IR sensor module to detect object for count rotation of any rotating body.

5. Distance Measurement
Ultrasonic sensors are great tools to measure distance without actual contact and used at several places like water level measurement, distance measurement etc. This is an efficient way to measure small distances precisely. In this project we have used an Ultrasonic Sensor to determine the distance of an obstacle from the sensor.

6. LPG Leakage Detector
While LPG is an essential need of every household, its leakage could lead to a disaster. To alert on LPG leakage and prevent any mishappening there are various products to detect the leakage. Here we have developed an Arduino based LPG gas detector alarm. If gas leakage occurs, this system detects it and makes an alert by buzing the buzzer attached with the circuit. This system is easy to build and anyone who have some knowledge of electronics and programing, can build it.

7. Digital Dice
We all are familiar with dice and often played LUDO or SANP SIDI (Snake & Ladders) game by using dice. Dice is a squire type solid box which contains 6 different numbers on all of its sides. We throw dice on a surface to get a random number while playing the games. In this project we have tried to replicate it with a digital dice using arduino uno board. In place of throwing the dice, here we need to press a button to get a random number between 0 to 6.

Hope you like the above projects. Find here more such arduino based projects here: http://circuitdigest.com/arduino-projects

Timer Circuits

Sometimes we need to create timer circuits in our product and application designs. 555 timer is one of the popular and efficient IC to provide accurate time delays in the circuits. Here is a tutorial which guides you to create different time delays in the circuit using IC 555.

Here 555 IC is configured in monostable mode and by changing different resistor values, different time delay is achieved.

Check out the complete circuit here: 1 minute timer circuit

For more such circuits, check our 555 Circuits section.