However, there are two standout options you should consider, especially if you're looking for a beginner-friendly board: the Uno Rev3 and the Uno R4 WiFi ... original and Rev2 boards, the Rev3 ...

Connector to add external battery to real-time clock (RTC) inside Renesas MCU (MCU RTC power pad held to 5V rail on Minima) Secondary (wireless) processor: 240MHz 3.3V dual core 32bit Espressif ...