AVR Introduction

AVR Introduction

ATmega8 microcontroller

• 8-bit microcontroller
• Advanced RISC Architecture
• 512 Bytes EEPROM
• In-system programming by On-chip boot program
• 23 programmable I/O lines
• 28 lead PDIP
• 3 PWM channel
• 6 channel ADC in PDIP package
• 4.5V-5.5V operating voltages

ATmega8 microcontroller

Pin diagram

ATmega8 microcontroller

Pin configuration

• PORT B, PORT C and PORT D each port have 8 pins.
• PIN 2 : RXD, Usart serial communication interface
• PIN 3 : TXD, Usart serial communication interface 
• PIN 4 : INT0, I/O pin, External interrupt
• PIN 5 : INT1, I/O pin, External interrupt
• PIN 6 : XCK, Timer external counter input, Usart external clock I/O
• PIN 7 : VCC
• PIN 8 : GND
• PIN 9 : XTAL1
• PIN 10 : XTAL2
• PIN 11 : T1, Timer external counter input
• PIN 12 : AIN0, Analog comparator positive input
• PIN 13 : AIN1, Analog comparator negative input
• PIN 14 : ICP1, Timer/ Counter1 input capture pin
• PIN 15 : OC1A, I/O pin, PWM channel output
• PIN 16 : OC1B, I/O pin, PWM channel output
• PIN 17 : OC2, I/O pin, Timer/ counter output compare match output
• PIN 18 : MISO, Master input and slave output
• PIN 19 : SCK, Serial clock
• PIN 20 : AVCC, For analog to digital converter
• PIN 21 : AREF, For referance voltage
• PIN 22 : GND, For ADC 
• PIN 23 : ADC0
• PIN 24 : ADC1
• PIN 25 : ADC2
• PIN 26 : ADC3
• PIN 27 : SDA, TWI interface
• PIN 28 : SCL, TWI interface

👉  PIN 23-PIN 28 : ADC channel, input pins.