The devboards have headers for the ESP8266, an on-board ATmega328 for Arduino Uno compatibility, and a USB to serial converter to make interfacing easy.

Someone has invented a way to add Wi-Fi to a standard Arduino Uno, by proposing a module that drops into the DIL socket normally reserved for the ATmega328 – it will not work with Unos that have a ...

Arduino introduces its new module »Uno R4«. It is the successor of the R3 module and contains a Wi-Fi module in the extended version. It is also the first Arduino module with 32-bit microcontroller.

It’s a dollar more than the ESP8266. The datasheet for the module goes over all the gritty details. While this chip has 3.6V I/Os, there are some 5V tolerant pins – a boon for the Arduino crowd.

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.

Details of Arduino UNO R4 32-bit board revealed, including the 12x8 RED LED matrix on board and connectivity for IoT applications.