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 Arduino UNO R4 boasts a 3x performance increase over the UNO R3 and , in addition, SRAM has been upgraded from 2kB to 32kB, and flash memory from 32kB to 256kB to support more complex projects.

This second version – Rev2 – of the Arduino Uno WiFi board is functionally the same as the Arduino Uno Rev3, but also comes with built-in WiFi, enabling easy connection to the Internet, plus the ...

Arduino has announced the new UNO R4 board family for prototyping and learning. The new models feature a faster microcontroller, a USB-C connector, improved power, Wi-Fi and Bluetooth LE, and more.

Massimo Banzi, co-founder and chairman of Arduino, announced the UNO R4 during Arduino Day 2023. He believes the UNO R4 is a new chapter in the UNO story and the perfect way to move forward, ...

Features common to Arduino R4 – ‘WiFi’ (€25, below) and ‘Minima’ (€18, right) IO connections are in physically similar positions to Uno R3, and IO remains 5V. USB connector changed to Type-C. 6 – ...

Scheduled to appear in late May, Uno R4 will come in two versions: the plain ‘Uno R4 Minima’, and ‘Uno R4 WiFi’ with an Espressif S3 WiFi module that also gives it Bluetooth Low Energy. “We ...