Pinout

ATtiny85 (DIP-8) pinout

Pins

Core	8-bit AVR
Supply voltage	ATtiny85: 2.7–5.5 V; ATtiny85V: 1.8–5.5 V
Clock speed	Up to 10 MHz at 2.7–5.5 V, 20 MHz at 4.5–5.5 V; internal 8 MHz RC oscillator
Flash memory	8 KB
SRAM	512 bytes
EEPROM	512 bytes
I/O pins	6 (5 + RESET, usable as I/O if reset is disabled)
ADC	10-bit, 4 channels
Timers / PWM	Two 8-bit timers (Timer1 can run from a 64 MHz PLL); up to 3 PWM outputs in Arduino cores
Serial interfaces	USI (used for I2C or SPI in software); no hardware UART
DC current per I/O pin	40 mA absolute max; 200 mA total through VCC/GND
Operating temperature	−40–85 °C (industrial grade)
Package	DIP-8, SOIC-8, QFN-20

555 timer (DIP-8)Supply voltage: NE555: 4.5–16 V; CMOS TLC555: 2–15 V; ICM7555: 2–18 V; Supply current (no load): NE555: ≈ 3 mA typ at 5 V, ≈ 10 mA at 15 V; CMOS…
74HC14 hex Schmitt-trigger inverter (DIP-14)Logic family: 74HC (high-speed CMOS); Gates: 6 Schmitt-trigger inverters; Supply voltage: 2–6 V
MAX232 RS-232 line driver (DIP-16)Supply voltage: 4.5–5.5 V (single 5 V supply); Supply current: ≈ 8 mA typ (no load); Channels: 2 drivers + 2 receivers
DS3231 RTC module (ZS-042, I2C)Supply voltage: Chip: 2.3–5.5 V; module typically used at 3.3–5 V; Interface: I2C, up to 400 kHz; I2C address: 0x68 (RTC); 0x57 for the on-board AT24C32…
74HC595 shift register (DIP-16)Logic family: 74HC (high-speed CMOS); Function: 8-bit serial-in, parallel-out with output latch and 3-state outputs; Supply voltage: 2–6 V
74HC165 parallel-in shift register (DIP-16)Logic family: 74HC (high-speed CMOS); Function: 8-bit parallel-in, serial-out (QH plus inverted QH output); Supply voltage: 2–6 V
ATmega328P (DIP-28)Core: 8-bit AVR; Supply voltage: 1.8–5.5 V; Clock speed: Up to 4 MHz at 1.8 V, 10 MHz at 2.7 V, 20 MHz at 4.5–5.5 V; internal 8 MHz RC oscillator
PCF8574 I2C port expander (DIP-16)Supply voltage: 2.5–6 V; Interface: I2C, 100 kHz (standard mode); I2C address: PCF8574: 0x20–0x27; PCF8574A: 0x38–0x3F (set by A0–A2)