AVR - INTRODUCTION & TYPES

If you are new to AVR micro controllers, just go through the page and successive pages.  Just have a glance on the differences in the AVR micro controllers.  Initially, it is not possible to have full idea about all micro controllers.  Just read on . . .

AVR is a brand name for micro controllers of MICROCHIP Corporation Inc (earlier Atmel Corporation Inc). Variety of microcontrollers are available from Atmel.  Although, there is no certain full form for AVR, but normally it is known as Alf and Vegard's RISC (Reduced Instruction Set Computer Architecture) processor. 

Now (for the time being), our discussion is made limited to Make-at-Home projects.  We are explaining about the micro-controllers, which are easily available and easily used for our projects.  Normally, an AVR micro-controller operates between 1.8VDC to 5.5VDC and the clock frequency is dependent on the Supply voltage, i.e., higher voltage is required for higher clock frequencies.  Almost all AVR micro-controllers used in our project uses 5VDC supply for the projects

The basic data about the AVR micro-controllers, which are frequently used in our projects, is listed below for quick reference.  The Power supply pins (red and blue) and programming pins (pink) are marked in pinouts for easy understaing.  All the AVR micro-controllers discussed here are available with pre-calibrated internal clock frequency (1MHz by default).  A crystal may be used externally to pins marked as XTAL1 and XTAL2 (or square frequency at CLK pin) and registers must be programmed accordingly. 

ATTINY 13:

ATTINY13 micro-controller is available in 8 pin PDIP

(and other) package. 

It has following main features:

1KB Flash memory (ROM) to hold the program

64 Bytes of SRAM and 64 Bytes of EEPROM

6 Digital Input/Ouput pins, maximum

10 bit ADC, 4 channels

8 bit timer/counter, 1 number

PWM channels, 2 channels

Datasheet link (courtesy Microchip):  http://ww1.microchip.com/downloads/en/DeviceDoc/doc2535.pdf

ATTINY13 PHOTO.jpg
ATTINY13 PINOUTS.jpg

ATTINY 25/45/85:

ATTINY 25/45/85 micro-controller is available in 8 pin PDIP

(and other) package. 

It has following main features:

2/4/8 KB Flash memory (ROM) to hold the program

128/256/512 Bytes of SRAM

128/256/512 Bytes of EEPROM

6 Digital Input/Ouput pins, maximum

10 bit ADC, 4 channels and more

8 bit timer/counter, 2 numbers

PWM channels, 2 channels

TWI communication

USI communication

Datasheet link (courtesy Microchip):  https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-2586-AVR-8-bit-Microcontroller-ATtiny25-ATtiny45-ATtiny85_Datasheet.pdf

ATTINY13 PHOTO.jpg
ATTINY85 PINOUTS.jpg

ATTINY 24/44/84:

ATTINY 24/44/84 micro-controller is available

in 14 pin PDIP (and other) package. 

It has following main features:

2/4/8 KB Flash memory (ROM) to hold the program

128/256/512 Bytes of SRAM

128/256/512 Bytes of EEPROM

12 Digital Input/Ouput pins, maximum

10 bit ADC, 8 channels and more

8 bit timer/counter, 1 number

16 bit timer/counter, 1 number

PWM channels, 2 channels

TWI communication

USI communication

Datasheet link (courtesy Microchip):  http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-7701_Automotive-Microcontrollers-ATtiny24-44-84_Datasheet.pdf

attiny84_photo.jpg
ATTINY84 PINOUTS.jpg

ATTINY 2313/4313:

ATTINY 2313/4313 micro-controller is available

in 20 pin PDIP (and other) package. 

It has following main features:

2/4 KB Flash memory (ROM) to hold the program

128/256 Bytes of SRAM

128/256 Bytes of EEPROM

18 Digital Input/Ouput pins, maximum

8 bit timer/counter, 1 number

16 bit timer/counter, 1 number

PWM channels, 4 channels

TWI communication

USI communication

USART communication, Full Duplex

Datasheet link (courtesy Microchip):  http://ww1.microchip.com/downloads/en/DeviceDoc/doc8246.pdf

http://ww1.microchip.com/downloads/en/devicedoc/atmel-2543-avr-attiny2313_summary.pdf

ATTINY 2313 PINOUTS.jpg
ATTINY2313-PHOTO.png

ATMEGA 8:

ATMEGA 8 micro-controller is available

in 28 pin PDIP (and other) package. 

It has following main features:

8 KB Flash memory (ROM) to hold the program

1 KB of SRAM

512 Bytes of EEPROM

23 Digital Input/Ouput pins, maximum

10 bit ADC, 6 channels in PDIP(8 in TQFP)

8 bit timer/counter, 2 number

16 bit timer/counter, 1 number

PWM channels, 3 channels

TWI communication

SPI communication

USART communication, Programmable

Datasheet link (courtesy Microchip):  http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-2486-8-bit-AVR-microcontroller-ATmega8_L_datasheet.pdf

ATMEGA8 PHOTO.png
ATMEGA8 PINOUTS.jpg

ATMEGA 48/88/168/328:

ATMEGA 48/88/168/328 micro-controller is available

in 28 pin PDIP (and other) package. 

It has following main features:

4/8/16/32 KB Flash memory (ROM) to hold the program

512/1024/1024//2048 Bytes of SRAM

256/512/512/1024 Bytes of EEPROM

23 Digital Input/Ouput pins, maximum

10 bit ADC, 6 channels in PDIP (8 in TQFP)

8 bit timer/counter, 2 number

16 bit timer/counter, 1 number

PWM channels, 4 channels

TWI communication

SPI communication

USART communication, Programmable

Datasheet link (courtesy Mouser):  https://www.mouser.com/pdfdocs/gravitech_atmega328_datasheet.pdf

ATMEGA328 PINOUTS.jpg
ATMEGA8 PHOTO.png

ATMEGA 16/32:

ATMEGA 16/32 micro-controller is available

in 40 pin PDIP (and other) package. 

It has following main features:

16/32 KB Flash memory (ROM) to hold the program

1/2 KB of SRAM

512/1024 Bytes of EEPROM

32 Digital Input/Ouput pins, maximum

10 bit ADC, 8 channels 

8 bit timer/counter, 2 number

16 bit timer/counter, 1 number

PWM channels, 4 channels

TWI communication

SPI communication

USART communication, Programmable

Datasheet link (courtesy Microchip): 

http://ww1.microchip.com/downloads/en/devicedoc/atmel-8154-8-bit-avr-atmega16a_datasheet.pdf

http://ww1.microchip.com/downloads/en/DeviceDoc/doc2466.pdf

http://ww1.microchip.com/downloads/en/devicedoc/doc2503.pdf

ATMEGA16 PINOUTS.png
ATMEGA16 PHOTO.png

SUMMARY:

Handling of packages other tan PDIP is difficult and need PCB with SMT.  So, the pinouts are shown for PDIP only.  Other package details and pinouts may be obtained from datasheets (link is provided at the end) .

Selection of a micro-controller depends on the memory requirement, communication system requirement, space availability, number of Input/Outputs, cost of the micro-controller etc.

1) The AVR PDIP micro controllers generally available in 5 packages

     8pin, 14pin, 20pin, 28pin and 40pin. 

2) All 28 pin micro-controllers have almost same pinouts, except memory capacity and communication methods.

3) ARDUINO UNO uses ATMEGA328 with bootloader.