Interactive chip reference
ATmega328P DIP-28 pinout
ATmega328P 28-pin DIP-28 pinout. Atmel 8-bit AVR microcontroller — 32KB flash, 2KB SRAM, multi-package pinout set
Pin reference
| Pin | Name | Function | Group |
|---|---|---|---|
| 1 | PC6 | RESET — or PCINT14 | control |
| 2 | PD0 | RXD — USART receive | bidir |
| 3 | PD1 | TXD — USART transmit | bidir |
| 4 | PD2 | INT0 — external interrupt 0 | bidir |
| 5 | PD3 | INT1 / OC2B / PWM | bidir |
| 6 | PD4 | T0 / XCK / PCINT20 | bidir |
| 7 | VCC | Digital supply voltage | power |
| 8 | GND | Ground | ground |
| 9 | PB6 | XTAL1 — crystal oscillator input | clock |
| 10 | PB7 | XTAL2 — crystal oscillator output | clock |
| 11 | PD5 | T1 / OC0B / PWM | bidir |
| 12 | PD6 | AIN0 / OC0A / PWM | bidir |
| 13 | PD7 | AIN1 / PCINT23 | bidir |
| 14 | PB0 | ICP1 / CLKO / PCINT0 | bidir |
| 15 | PB1 | OC1A / PWM / PCINT1 | bidir |
| 16 | PB2 | /SS / OC1B / PCINT2 | bidir |
| 17 | PB3 | MOSI / OC2A / PCINT3 | bidir |
| 18 | PB4 | MISO / PCINT4 | bidir |
| 19 | PB5 | SCK / PCINT5 | clock |
| 20 | AVCC | Analog supply voltage — ADC | power |
| 21 | AREF | Analog voltage reference for ADC | control |
| 22 | GND | Ground | ground |
| 23 | PC0 | ADC0 / PCINT8 — analog channel 0 | bidir |
| 24 | PC1 | ADC1 / PCINT9 — analog channel 1 | bidir |
| 25 | PC2 | ADC2 / PCINT10 — analog channel 2 | bidir |
| 26 | PC3 | ADC3 / PCINT11 — analog channel 3 | bidir |
| 27 | PC4 | ADC4 / SDA / PCINT12 — I2C data | bidir |
| 28 | PC5 | ADC5 / SCL / PCINT13 — I2C clock | bidir |
View the interactive ATmega328P package diagram and labeled pin details on WhichPin.