The Arduino Uno-compatible board has an MCS-51 (often called 8051 instead) instead of the usual ATmega328P/ATmega168. Specifically, [ElectroBoy] uses the AT89S52 .

The Zero is a 32-bit extension of Arduino’s flagship Uno board, developed jointly by the Arduino team and Atmel, targeted at helping developers prototype smart devices.

Arduino, the world's leading open-source hardware and software platform, today announced the launch of its next-generation UNO board, a significant re ...

The Arduino UNO R4, featuring the Renesas RA4M1 (Arm Cortex-M4) running at 48MHz, boasts a 3x performance increase over the UNO R3. Additionally, SRAM has been upgraded from 2kB to 32kB, and flash ...