Atmega8 AVR microcontroller engineering 


The acronym for AVR Microcontroller is "Advanced Virtual RISC" and MCU is a short term for Microcontroller. A microcontroller is a small computer on a single chip that is also called a microcontroller. Similar to a computer, a microcontroller consists of a variety of peripheral devices such as input and output units, memory, timers, serial, and programmable data communications. Microcontroller applications include embedded applications and automatically controlled devices such as medical devices, remote controls, control systems, office machines, electrical tools, electronic devices, etc. There are various types of microcontrollers available in the market such as 8051 microcontroller, PIC and AVR. . This article provides brief information about the AVR Atmega8 microcontroller.

What is an AVR Atmega8 microcontroller?

In 1996, the AVR Microcontroller was produced by the Atmel Corporation. The microcontroller incorporates Harvard architecture that works quickly with RISC. The features of this microcontroller include different features compared to other modes such as -6 sleep modes, inbuilt ADC (analog to digital converter), internal oscillator and serial data communication, which executes instructions in a single execution cycle. These microcontrollers were very fast and used low power to operate in various power saving modes. Various configurations of AVR microcontrollers are available to perform different operations such as 8-bit, 16-bit and 32-bit. Please refer to the link below for; AVR microcontroller types

Atmega8 microcontroller

AVR microcontrollers are available in three different classes such as TinyAVR, MegaAVR and XmegaAVR

Tiny AVR microcontroller is small in size and used in many simple applications

Mega AVR microcontroller is very popular due to a large number of built-in components, good memory, and is used in modern to multi-purpose applications

Xmega AVR microcontroller is applied in demanding applications, which require high speed and huge program memory.

Description of the Atmega8 microcontroller pin

The main feature of the Atmega8 Microcontroller is that all but the 5 pins of the microcontroller support 2 signals. The Atmega8 microcontroller consists of 28 pins where pins 9,10,14,15,16,17,18,19 are used for port B, pins 23,24,25,26,27,28 and 1 are used for port C and pins 2 are used ,3,4,5,6,11,12 for port D.

Atmega8 microcontroller pin configuration



Pin -1 is the RST (reset) pin and applying a low level signal for longer than the minimum pulse length will result in a reset.

Pin-2 and pin-3 are used in USART for serial communication

Pin-4 and pin-5 are used as an external interrupt. One will be activated when an interrupt-aware portion of the case log is set and the other will be activated as long as the intrusion case is successful.

Pin-9 and pin-10 are used as timer oscillators as well as an external oscillator where the crystal is directly connected to the two pins. Pin-10 is used for a low frequency crystal oscillator or crystal oscillator. If the internal RC oscillator is used as the CLK source and an asynchronous timer is allowed, these pins can be used as a temporary oscillator pin.

Pin-19 is used as Master CLK o/p, and Slave CLK i/p for SPI channel.

Pin-18 is used as Master CLK i/p, dependent CLK o/p.

Pin-17 is used as o/p master data, i/p dependent data for the SPI channel. It is used as i/p when it is enabled by the slave and is bi-directional when the master allows it. This pin can also be used as an o/p comparator with an o/p match, which helps as an external output for the counter/counter.

Pin-16 is used as an i/p dependent option. It can also be used as a timer or a relatively 1 counter by arranging the PB2 pin as an o/p.

The Pin-15 can be used as an external o/p for a timer or a counter comparison match.

Pin-23 to Pins28 was used for ADC (Analog Input Digital Value) channels. Pin-27 can also be used as serial interface CLK & pin-28 can also be used as serial interface data

Pin-12 and pin-13 are used as an analog i/ps comparator.

Pin-6 and pin-11 are used as timer/counter sources.

Atmega8 AVR microcontroller architecture

The architecture of the Atmega AVR Microcontroller includes the following blocks.

Atmega8 microcontroller architecture

Memory: Contains 1KB of internal SRAM, 8KB of flash program memory and 512 bytes of EEPROM.

I/O Ports: It has three ports, port B, port-C and port-D and 23 I/O lines can be accessed from these ports.

Interrupts: The two external interrupt sources are located on port D. Nineteen vectors of dissimilar interrupts support nineteen events produced by the internal peripherals.

Timer/Counter: There are 3 internal accessible timers, 8-bit-2, 16-bit-1, offering several operating modes and supporting internal/external timing.

Serial Peripheral Interface (SPI): The ATmega8 microcontroller contains three integrated communication devices. One of them is SPI, 4 pins are allocated to the microcontroller to implement this communication scheme.

USART: USART is one of the most powerful communications solutions. The ATmega8 microcontroller supports both synchronous and asynchronous data transfer schemes. It has three pins dedicated to it. In many communication projects, the USART module is widely used to communicate with PC-Microcontroller.

Two-wire interface (TWI): TWI is another communication device found in the ATmega8 microcontroller. It allows designers to set up the b/n connection of two devices using two wires with a mutual GND connection, since the o/p of TWI is made using an open collector, so external pull-up resistors are mandatory. Circle.

Analog comparator: This module is integrated into an integrated circuit that provides a means of contrasting two voltages connected to the two comparator inputs through external pins linked to the microcontroller.

ADC: The built-in ADC (analog to digital converter) can change the analog i/p signal into digital data with 10-bit precision. To get the maximum out of a low-end application, this resolution is sufficient.

Atmega8 microcontroller applications

Atmega8 microcontroller is used to build many electrical and electronic projects. Some AVR atmega8 Microcontroller projects are listed below.

Project based on Atmega8

Project based on Atmega8

AVR Microcontroller LED Matrix Interfacing

UART communication between Arduino Uno and ATmega8

Communication between Optocoupler with ATmega8 microcontroller

AVR Controller Based Fire Alarm System

Light intensity measurement using AVR and LDR . microcontroller

AVR microcontroller based on 100mA Ammeter

Anti-theft alarm system based on ATmega8 microcontroller

AVR Microcontroller Interfacing for Joystick

AVR Microcontroller Interfacing for Flex Sensor

Stepper control using an AVR microcontroller

So, this is all about the Atmega8 microcontroller tutorial that includes, what is an Atmega8 microcontroller, architecture, pin configuration, and its applications. We hope you have a better understanding of this concept. Moreover, any doubts regarding this concept or to implement projects based on AVR microcontroller, please provide your feedback by commenting in the comments section below. What is the difference between Atmega8 and Atmega 32 microcontroller?