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.

The UNO R4 maintains the same form factor, shield compatibility, and 5V operating voltage as its predecessor with software compatibility also a priority, with most existing libraries and examples ...

Retaining the Arduino UNO form factor shield compatibility and 5V operating voltage yet powered by a 32-bit Cortex-M4 and a 3-to-16x increase in clock speed, memory and flash storage.

This partly obscured photo is the only one Arduino has allowed out so far “Designed for maximum compatibility, the Uno R4 maintains the same form factor, shield compatibility, and 5V operating voltage ...

Arduino Uno R4 WiFi comes with built-in Wi-Fi and Bluetooth capabilities, along with additional pins and a new, faster processor.

Arduino collaborated closely with partners Renesas and Espressif to create the ‘most compatible and powerful maker board on the market’.

The module requires both a USB interface and level shifter to interface the 2.8V levels of the module to the 5V Arduino Uno.