This is the SB116, an 8-bit programmer’s calculator powered by an Arduino Nano. It features a 128 x 64 pixel monochrome OLED display and can be powered by either a USB port or three AAA batteries.

The Arduino Nano is powered by an Atmel ATmega328. It's an 8-bit AVR microcontroller that operates at a clock speed of 16 MHz and comes with 2 KB SRAM, 1 KB EEPROM, and 32 KB flash memory.