AVR Projects Collection | 20 ATmega MCU Projects


AVR is a family of microcontrollers developed by Atmel beginning in 1996. These are modified Harvard architecture 8-bit RISC single-chip microcontrollers. ATmega series are one of the types of AVR microcontrollers with features like 4–256 KB program memory, 28–100-pin package, extended instruction set, and extensive peripheral set. These special features help students, hobbyists and engineers make innovative AVR projects. Let’s take a look at few interesting AVR projects.

AVR Projects: Digital Soil Moisture Meter

A soil moisture meter is used for indicating the water content of a given soil sample. As crop production requires water at different stages and in different amounts, it is important to measure soil moisture from time to time. This project monitors soil moisture content in irrigation farms by measuring the resistance to the flow of electric current between two metallic probes. These probes act as sensor elements that register moisture and change it into an electric value. This value is further processed into information by an electronic display.

Details about the project are available at: digital soil moisture meter.

Ultrasonic Radar Mode Using Microcontroller ATmega128

A radar system consists of a transmitter, transmitting a beam towards a target, which is reflected by the target as an echo signal. The receiver receives and processes the reflected signal to provide such information like the presence of a target, distance, position (moving or stationary) or speed, which is displayed on a display unit. Radar systems have a number of defense as well as civil applications. Air traffic control uses radars to track aircraft on the ground, in the air and to guide planes for smooth landings.

More details about this project are available at: ultrasonic radar model.

RFID Based Attendance System

This system can be used to take attendance for a student in school, college, and university. It also can be used to take attendance for workers in working places. Its ability to uniquely identify each person based on their RFID tag type of ID card make the process of taking attendance easier, faster and secure as compared to conventional method. The system can be connected to the computer through RS232 or Universal Serial Bus (USB) port and store the attendance in a database. An alternative way of viewing the recorded attendance is by using HyperTerminal software. A prototype of the system has been successfully fabricated. Radio frequency technology is used in many applications.

More details about this project is available at: RFID based attendance system.

Fingerprint Door Unlock System

This simple fingerprint sensor project using Arduino is very useful in door security, forensics, crime investigation, personal identification, attendance system and much more. In the future, there could be many more applications like fingerprint based driving license, bank accounts operation and so on. The whole system works on a simple matching algorithm. It compares previously-stored templates of fingerprints against users’ fingerprints for authentication purposes. In this project, only when an authorised person places a finger on the sensor, the door unlocks and the LCD displays a welcome message along with that person’s name.

More details about this project are available at: fingerprint door unlock system.

Sonar Water-Level Meter

A water-level indicator has two units: transmitter unit and receiver unit. The transmitter unit in the project is built around ATmega328P microcontroller (MCU) (IC1) with Arduino Uno bootloader, sonar sensor HC-SR04 connected at CON1, 433MHz transmitter (TX1), voltage regulator 7805 (IC2) and a few other components. A long spiral antenna is used for enhancement of its range. The contactless sonar sensor is placed at a strategic location on the tank so that it always gets the reflected signal from the water surface. The best place would be at the centre of a circular tank’s lid on top, or at the intersection of the diagonals of a rectangular tank’s top. The calculated tank level is transmitted with a coded authorisation to the receiver unit.

More details about this project are available at: sonar water-level meter.

AVR Projects: Android Phone-Controlled Robot

This is one of the interesting projects among AVR Projects because of the use of Android. The circuit is built around an Arduino UNO board (BOARD1), ultrasonic transceiver module HC-SR04, Bluetooth module JY MCU BT, motor driver L293D (IC1), DC motors M1 and M2, and a few common components. The circuit uses two 9V batteries—one to power the Arduino board and the other to power the motors. Regulated 5V supply for rest of the circuit is provided by the Arduino board itself. LED on the board indicates a presence of power supply.

More details about this project are available at: android phone-controlled robot

Temperature Controlled DC Fan

The main purpose of the circuit is to switch on the fan connected to DC motor when the temperature is greater than a threshold value. The microcontroller continuously reads the temperature from its surroundings. The temperature sensor acts as a transducer and converts the sensed temperature to electrical values. This is an analog value which is applied to the ADC pin of the microcontroller. The ATmega8 microcontroller has six multiplexed ADC channels with 10-bit resolution. The analog value is applied to one of the input ADC pins. Thus conversion occurs internally using successive approximation method.

More details about this project are available at: temperature controlled DC fan

Hydrogen Gas Monitoring and Alarm System 

This next project explains the making of a hydrogen gas monitoring and alarm system with AVR ATmega16 Microcontroller and 7-Segment Display using Analog MQ-8 Sensor. An Analog MQ-8 Hydrogen gas sensor is interfaced with the ATmega16 microcontroller and displays the Analog MQ-8 Hydrogen gas sensor value in 4 multiplexed common anode 7-Segment Displays. The output of Analog MQ-8 Hydrogen gas sensor value is compared with a threshold value continuously. If the Analog MQ-8 Hydrogen gas sensor output value is greater than the threshold value, the buzzer starts beeping.

More details about this project are available at: hydrogen gas monitoring and alarm system.

Anti-theft Alert System

In this next project, the ATMEGA works on internal 1MHz resistor-capacitor oscillator by default. Only when the accuracy of a clock is needed, as an application of high precision counting, an external crystal is attached. On sensing vibrations, the sensor sends a high pulse to ATMEGA8. At high pulse the controller sends an alert by turning the buzzer ON which makes noise. After that, only an authorized person can turn off the alarm. There will be 5 keys interfaced to ATMEGA, resulting in 4999 possible combinations. The correct combination will be programmed in the controller. So only the person with the correct code can turn OFF the alarm which was set by the vibration.

More details about this are available at: anti-theft alert system.

Line Follower Robot

This circuit consists of an ATmega8 microcontroller, two IR sensors, motors and motor driver IC. The line follower robot needs the mechanical arrangement of the chassis. Assume a two wheeled robotic vehicle with a castor wheel. The two IR sensors are mounted on the robot facing the Earth. When a robot is placed on the fixed path, it follows the path by detecting a line. The robot direction of motion depends on the two sensors outputs. When the two sensors are on the line of a path, the robot moves forward. If the left sensor moves away from the line, robot moves towards the right. Similarly, if right sensor moves away from the path, the robot moves towards its left. Whenever robot moves away from its path it is detected by the IR sensor.

More about this project are available at: line follower robot

AVR Projects: Home Automation System

This system consists of closely-networked Atmel’s ATmega8, which is an AVR based microcontroller with 512 bytes EEPROM on a 28-pin DIP package, 1024 bytes internal SRAM and 8kB internal flash memory. The complete system is assembled in a small, portable central processing unit (CPU) chassis for an aesthetic look and uninterrupted 24×7 usage. The circuit has four sections: main module, relay module, touch-control module and keyboard interface module. The system is housed in the CPU chassis of a desktop computer and is powered by 400W ATX power supply for error-free operation and proper power delivery to the system. The system has a standby mode indicator.

More about this project is available at: home automation system.

Digital Thermometer

A high precision digital thermometer is designed in this project. It is constructed with simple components like Arduino, LM35 temperature sensor and a LCD display. Working of the circuit is very simple. The temperature sensor i.e. LM35 continuously monitors room temperature and gives an analogue equivalent voltage which is directly proportional to the temperature. This analogue data is given to Arduino. The Arduino converts this analogue voltage value to digital temperature readings. This value is displayed on the LCD. The rate of change of temperature capture can be programmed in the code. The output displayed on the LCD is an accurate reading of room temperature in celsius.

More about this project is available at: digital thermometer.

Shadow Alarm System

Shadow alarms are usually used for protection against theft. A shadow alarm is a device that sounds an alarm when a shadow falls on it. Described here is a simple circuit of an Arduino-based shadow alarm. This compact shadow alarm unit is capable of sensing a moving shadow in a restricted area and is easily install-able on a wall, window or door to protect your valuables from theft. Constant lighting is required in the confined area to detect a moving shadow. It consists of an Arduino board, power supply, light-dependent resistor (LDR) sensor, buzzer, relay driver and a few other components. Arduino Uno board is the heart of this circuit.

More detail about this project is available at: shadow alarm system.

Density Based Traffic Signal System

Nowadays, controlling traffic is a major issue because of the rapid increase in automobiles and large time delays between traffic lights. In order to rectify this problem, we will go for density based traffic lights system. This project explains how to control the traffic based on density. This circuit uses IR sensors to measure traffic density. We have to arrange one IR sensor for each road; these sensors always sense the traffic on that particular road. All these sensors are interfaced to the microcontroller. Based on these sensors, the controller detects the traffic and manages the traffic system.

More details about this project are available at: density based traffic signal system.

Distance Measurement

We know that sound vibrations cannot penetrate through solids. So what happens is, when a source of sound generates vibrations they travel through the air at a speed of 220 meters per second. These vibrations when they meet our ear we describe them as sound. These vibrations cannot go through solid, so when they strike with a surface like a wall, they are reflected back at the same speed to the source, also known as an echo. This project uses ATMEGA32, Power supply (5v), AVR-ISP PROGRAMMER, JHD_16x2ALCD (16x2LCD) and HC-SR04 sensor.

More details about this project are available at: distance measurement.

AVR Projects: GSM Based Messaging

The brain of the circuit is Arduino Uno MCU board (BOARD1). A 16×2 LCD display (LCD1) is used for receiving and displaying the messages. When you want to show some information or message, you send an SMS to the GSM modem. The Arduino’s MCU reads the GSM modem and sends it to the LCD. This project uses the LCD in 4-bit mode, which means only four data lines are required to display the data. GSM modem SIM900A (connected with CON2 and CON3) sends the commands in text mode to Arduino Uno using an RS232 interface. 

More about this is available at: GSM based messaging.

Smart Remote Control

This project uses the Arduino Yun, (ATmega32u4), which is a special Arduino that is perfect for network-connected devices. The Yun has two processors, one of which runs the Linux operating system and can connect to wired or wireless networks. The second processor is the same as the one used in Arduino Leonardo. It has great compatibility with Arduino libraries and hardware. This project uses an infrared LED and receiver to send and receive remote control signals.

More about this is available at: smart remote control.

Vehicle Tracking System

Circuit connections of this vehicle tracking system project are simple. By using Software Serial Library here, serial communication is allowed and the Rx pin of GPS module is left open. By default Pin 0 and 1 of Arduino are used for serial communication but by using the Software Serial library, we can allow serial communication on other digital pins of the Arduino. 12 Volt supply is used to power the GPS Module.

More about this is available at: vehicle tracking system.

Tilt Detector

One of the interesting projects among AVR projects is Arduino based tilt detector. An accelerometer, which is an electro-mechanical device, can be used for various applications like tilt detection, obstacle detection, motion inputs, earthquake sensing, etc. Tilt detection is a simple application of an accelerometer where a change in angular position of the system in any direction is detected and indicated through four LEDs. An Arduino Uno board is used to process the data received from the accelerometer and switch on the corresponding LED to indicate the direction of tilt. 

More about this is available at: tilt detector.

Electronic Voting System

One of the useful projects among AVR projects is electronic voting machine; this helps in privacy and prevents malpractice during voting. This project designs a simple voting machine using ATmega32A microcontroller. To keep everything simple the voting machine has been minimized to four people. There are four buttons for four people and whenever a button is pressed, a vote goes for the corresponding person and the number of votes each person gets  will be shown on a LCD.

More about this can be found on electronic voting system

Let us know if you liked this list of 20 AVR projects. If you have some of your own, you would like to add to this list of AVR projects, let us know in the comments below.


  1. Can you provide me with circuit and source code for a project on ‘library automation using barcode reader’. We plan to use a barcode reader with usb port so would need to connect a usb port on the pcb thus eliminating the use of voltage convertor like max232 had we used a barcode with rs232 port. We are using pic16f877. So please see if u could help…

  2. pls i need materials in chapter on digital based microcontoller atmega 328p. am writting my project on the topic.


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