This is the famous Atmel ATtiny85 microcontroller, specifically the 20MHz Attiny85-20PU. This is a popular AVR microcontroller based on RISC architecture, and packs a decent set of functions despite its size and low number of pins. Check out the SparkFun Tiny AVR Programmer for using with this IC. Features * Atmel 8-bit AVR RISC-based microcontroller * 8KB ISP flash memory * 512B EEPROM * 512-Byte SRAM * 6x general-purpose I/O lines * 32x general purpose working registers * 1x 8-bit timer/counter with compare modes * 1x 8-bit high speed timer/counter * USI * Internal and external Interrupts * 4-channel 10-bit A/D converter * Programmable watchdog timer with internal oscillator * 3x Software selectable power saving modes * DebugWIRE for on-chip debugging * Achieves a throughput of 20 MIPS at 20 MHz and operates between 2.7-5.5 volts. Resources * Datasheet https://elecena.pl/product/22721334/atmel-attiny85-20mhz 2023-03-07 https://elecena.pl/product/22721334/atmel-attiny85-20mhz 2023-05-04 https://elecena.pl/product/22721334/atmel-attiny85-20mhz 2023-05-24 https://elecena.pl/product/22721334/atmel-attiny85-20mhz 2023-12-27 https://elecena.pl/product/22721334/atmel-attiny85-20mhz 2024-09-19 https://elecena.pl/product/22721334/atmel-attiny85-20mhz 2024-11-29 https://elecena.pl/product/22721334/atmel-attiny85-20mhz 2024-11-30 https://elecena.pl/product/22721334/atmel-attiny85-20mhz 2025-11-28 https://elecena.pl/product/22721334/atmel-attiny85-20mhz 2025-11-29