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

Arduino has shrunk the UNO R4 with the Arduino Nano R4 board equipped with the same 48 MHz Renesas RA4M1 32-bit Arm ...

The Uno is such a popular board that it's most folks' first pick when they need of a microcontroller platform for their projects, especially if they're just getting started with Arduino.

Another pin you can use on the Nano to power it up is the 5V pin (located on Pin 27, close to the VIN pin at the end of the board). This pin mostly serves as a power output pin that supplies power ...

Arduino has launched its next generation of UNO boards, introducing a 32-bit Renesas microcontroller and Espressif ESP32-S3 module, one-click cloud connectivity and plenty of I/O plus a 12×8 red LED ...