Introduction to AVR Microcontroller

Hello readers I hope you all are doing great and enjoying your life. In today’s post, we will have a detailed look at the Introduction to AVR Microcontroller. The AVR is a group of microcontrollers in 1996 the first time it was created by Atmel. which was the first time created in 1996 and after that it was obtained by the American company Microchip Technology in 2016. It is based on Harvard architecture and eight-bit RISC (reduced instruction set computer) having a single chip.

This is the first microcontroller that uses flash memory for data storage while other controllers use older types of memory for data storage such as ROM, EPROM, and EEPROM. There is numerous common applications such as embedded systems in which it is used. In today’s post, we will have a detailed look at its working, pinout, features, and some other related parameters. So let’s get started with an Introduction to the AVR Microcontroller.

Introduction to AVR Microcontroller

• The AVR is a type of MCU which is created by Atmel this controller provides numerous features that are lacking in other types of MCUs.
• This microcontroller is like our personal computer which has different types of elements such as EEPROM, RAM, and microprocessor, all these and some other components exist on this board.

• These modules are available in different types of arrangements such as surface mounting and hole mounting.
• This controller comes with eight to one hundred pinout configurations the type of AVR which has sixty-four pinouts is available in surface mount.
• In 2006 microcontroller of thirty-two-bit had an AVR32 structure. This module has a different structure than the eight-bit AVR controller and was a competitor of the processor based on ARM.
• This module comprises of thirty-two-bit data buses and uses SIMD and DSP commands with some other factors.
• This controller comprises of flash memory, EEPROM, and static random access memory all these memories are assembled on a single board.
• At some controllers, there is a port for a parallel exterior bus which used to connect some extra memory if required.
• In all types of AVRs except TinyAVR there is serial interfacing exists which helps to connect EEPROM having large space.

Features of AVR Microcontroller

• These are some main features of the AVR microcontroller which are described here with the details.
• This module performs numerous functions that have two-directional inputs and output ports which can be configured with the pull-up resistances.
• There are numerous inner oscillators, consisting of RC oscillators also exits on this board.
• There is a flash memory of two fifty-kilobyte storage spaces on this board.

• The EEPROM having a space of four-kilo byte is assembled on this board.
• The static random access memory having a space of sixteen kilobytes exists on this board.
• There are 2 timers of eight-bit and sixteen-bit exits on this board.
• The pulse width modulation output exists on this board.
• There is an analog comparator also assembled on this module.
• There is a twelve-bit analog-to-digital converter with the multiplex having sixteen channels on this board.
• There is a twelve-bit digital-to-analog converter that exists on this board.
• It uses I2C and TWI interfacing for communication.
• Its operating voltage is 1.8 volts.

Pinouts of AVR Microcontroller

• The pinout of this board is described here with the details.

Port A

• This port comprises of PA0 to PA7 pinouts.
• These pinouts of this port operate as analog inputs for analog to digital converters.
• This port can also be used as an eight-bit two-directional input and output port in the absence of analog to digital converter.

Port B

• In this port, there are pinouts from PB0 to PB7 exist. It is an eight-bit two-dimensional input and output which comprises of pull-up resistance.

Port C

• In this port PC0 to PC7 pinouts exist. It is also an eight-bit two-dimension input and output having inner pull-up resistance.

Port D

• In this port the pinouts from PD0 to PD7 exist, This port is also an eight-bit two-dimension input and output port having inner pull-up resistance

RESET

• This pinout is used to reset the controller.

XTAL1

• It is used as input to the inverting oscillator amplifier and also used as input pinout to the inner clock circuitry.

AVcc

• This pin is used to provide voltage to port A and analog to digital converter.

AREF

• This pinout is used as a reference pinout for analog to digital converters.

Types of AVR Microcontroller

Atmega8 AVR Microcontroller

• The type of AVR controller comes with 28 pinouts with some other components such as a static RAM of one kilobyte, flash memory of 8 KB, and 2 external interrupts.
• RISC architecture of that controller, and it is a product of Microchip. It also comes in 3 packages: PDIP, MLF, and TQFP.
• For PDIF, it comes with 28 pinouts, and other packages have 32 pins for making connections with external devices.
• It stores programs and other data in an 8KB flash memory unit.

Atmega32 AVR Microcontroller

• This controller is also an RISC-based controller and uses less power with high performance. Its working voltage range is 1.8 to 5.5 volts.
• Its main features are ISP flash memory of 32 KB, 2 KB static RAM, and general-purpose input and output lines.
• It also comes with 32 registers and JTAG interfacing for connection.
• It is also configured with the serial communication protocol USART, SPI, and inner and external interrupts.
• It also has a programmable watchdog timer with an internal oscillator, a 10-bit 8-channel A/D converter, etc.
• It is also used in motor control circuits, temperature control circuits, and also part of coffee machines and vending machines.

Atmega16 AVR Microcontroller

• This type of controller comes as part of Atmel’s Mega AVR group of controllers, and it is an 8-bit configuration. It comes with 40 pins with configuration of RISC architecture and also has 131 instructions.
•  Its other features are static RAM of 1 KB, a 16 KB memory unit, and 512 byte EEPROM.
• It also comes with 32 general-purpose registers and an instruction set connected with ALU.
• It comes with a 10K flash memory unit and 100K EEPROM.
• Its mostly instruction comes with a single machine cycle and is operated with 16 MHz of maximum frequency.
• Its basic use is for duty cycle and frequency measuring of different components.

Atmega328 AVR Microcontroller

• The Atmega328 AVR microcontroller is a low-power user controller with an 8-bit RISC-based microchip that comes with 32 KB of ISP flash memory and also has read and write features.
• Its working voltage is in the range of 1.8 to 5.5 volts.
• Its main features are
  • EEPROM-1 KB
  • 23-general purpose I/O lines
  • 32 general-purpose registers,
  • serial programmable  USART
  • SRAM-2 KB,
  • SPI serial port ,
  • flexible timer or counters-3, including compare modes,
  • 2-wire serial interface,
  • 10-bit 6-channel A/D converter,
• This controller is part of electronic projects that need low power and low-cost assembly. It is used in Arduino developments such as Arduino Nano, Arduino Uno, and Arduino Pro Mini models.

AVR Microcontroller Architecture

I/O Ports

• There are four 8-bit I.O. ports configured on the AVR controller that are
  • PORT-A
  • PORT-B
  • PORT-C
  • PORT-D.

Inner-calibrated oscillator

• This controller comes with inner oscillators whose main function is to operate the clock or CLK signals. The controller is confused for one megahertz inner calibrated oscillator; the result is that the is that the highest inner oscillator frequency is about 8 MHz.

ADC Interface

• There are 8-channel ADCs with 10-bit resolution connected on this board. Their main operation is to read analog input signals.

Timers

• It has two 8-bit and a single 16-bit counter or timer. The basic work of the timer is to produce accurate results, such as time delay for two operations.

Watchdog Timer

• This timer is connected to the inner oscillator. Its main function is to monitor and reset the controller if the code is not working after applications.

Byte Addressable EEPROM

• There is EEPROM-512 bytes configured on it, and nonvolatile memory is used for data storage and best to store door lock coding.

SRAM

• There is one KB of inner STatic RAM in this controller, and it is also a volatile memory unit. It has some parts used for general-purpose registers and parts used by the CPU, etc.

ISP

• This memory is programmed without the use of a detaching chip in the circuit and helps to reprogram the controller if connected in the circuit.

SPI

• SPI is used as a serial communication protocol for different devices with the help of CLK. The data transmission speed of SPI is higher as compared to USART.

TWI

• It is a two-wire interface that is used for the connection of different devices in the network. That helps to transmit data to different devices at one time.

DAC

• The DAC is controlled and used for performing the reverse process of ADC. It is sued for digital to analog conversion applications.

Interrupts

• 21 interrupts are configured, and out of that, 16 are inner and others are external. Inner interrupts control USART, ADC, Timers, etc.

USART

• USART used for the connection of external communication devices in a serial fashion

General Purpose Registers

• It has 32 registers connected with ALU to the CPU.

Flash EEPROM

• It stores data provided by users in the AVR controller. That program can easily be removed with a single unit electrically. This memory unit is non-volatile, and if power is not connected, the program will be removed. This controller has a 16KB programmable Flash EEPROM.

Applications of AVR Microcontroller

• These are some important applications of AVR microcontrollers.
• It is used in different types of embedded systems.
• It is used in electronic devices,
• It used in industries for the control of different machines

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So friends that is a detailed post about AVR microcontroller if you have any further questions ask in comments. Thanks for reading. Have a good day