Thirteen years later, they finally released an upgraded model — Arduino UNO R4. Compared to the old version, the new model has made significant improvements in computing power, memory, and network connectivity.

Arduino UNO R4 has a design and appearance similar to R3. However, the UNO R4 no longer uses the ATmega328P chip but has switched to an ARM Cortex-M4, with a working frequency of 48 MHz, 32 KB of RAM, and 256 KB of flash memory. It can be powered by a 5V power supply.

Comparison of parameters between UNO R4 and UNO R3

This model comes in two versions: Minima and Wi-Fi. Both versions use the ARM Cortex-M4 chip, with the main differences being:

Wireless Connectivity: The Arduino UNO R4 WiFi integrates an ESP32-S3 module, supporting both Wi-Fi and Bluetooth connections. The Arduino UNO R4 Minima does not have wireless connectivity but can connect to other wireless modules via the Qwiic connector.

LED Matrix: The Arduino UNO R4 WiFi has a built-in 12×8 LED matrix that can be used to display graphics or text. The Arduino UNO R4 Minima does not have an LED matrix.

VRTC and OFF Pins: The Arduino UNO R4 WiFi has a VRTC pin that can power the ESP32-S3 module to maintain Wi-Fi connectivity in low-power mode. It also has an OFF pin to turn off the ESP32-S3 module to save power. The Arduino UNO R4 Minima does not have these two pins.

Appearance of the Wi-Fi version

Price of the Wi-Fi version

Appearance of the Minima version

Price of the Minima version

Due to its powerful design and reliable performance, the Arduino UNO R4 is a development board that IoT beginners should not miss, and it is also suitable for experienced users to upgrade their Arduino projects.