Atmel 8-bit AVR microcontroller with 16KB ISP flash memory, 1KB SRAM, 512B EEPROM, an 8-channel/10-bit A/D converter. The device supports a throughput of 20 MIPS at 20 MHz and operates between 2.7-5.5 volts.
Comes in 28 pin DIP package. 23 I/O lines.