The Arduino UNO R4 WiFi is a powerful evolution of the classic UNO line, merging dual microcontrollers to offer robust processing and wireless capabilities—all while maintaining full UNO R3 compatibility. It skillfully combines robust hardware, wireless capabilities, interactive peripherals, and full compatibility with existing ecosystems—all in a compact and familiar form factor.

Features :

• Dual-core architecture: Combines a Renesas RA4M1 (ARM Cortex-M4) microcontroller with an Espressif ESP32-S3 Wi-Fi/Bluetooth co-processor.
• UNO form factor: Same pinout, shield compatibility, and 5 V operating logic as Arduino UNO R3.
• Extended I/O & hardware peripherals: On-board 12×8 LED matrix, Qwiic I²C connector, onboard DAC, CAN bus support, OP-AMP, RTC with battery support, and HID over USB.
• Renesas RA4M1 (primary MCU): 32-bit Cortex-M4 with FPU, featuring RTC, DAC, CAN, OP-AMP, MPU, CTIS, high-resolution ADC, DMA, and more. Operates at 5 V, enabling full UNO shield compatibility.
• ESP32-S3 (secondary MCU): Provides Wi-Fi and Bluetooth LE, operating at 3.3 V. Communicates with RA4M1 via a TXB0108 level shifter. Also accessible via a dedicated ESP header for advanced uses.
• LED Matrix: Build dynamic displays and animations directly on-board.
• Qwiic Connector: Easy plug-and-play I²C connectivity within the SparkFun Qwiic ecosystem.
• RTC with Battery Backup (VRTC) and Remote-OFF Pin: Enable autonomous timekeeping and power control.
• Diagnostics and HID: Built-in mechanisms to catch crashes, plus USB-based keyboard/mouse emulation.

Specifications :

• Microcontrollers:
  • Renesas RA4M1 (Cortex-M4F, 48 MHz)
  • ESP32-S3-MINI-1-N8 (dual-core Xtensa LX7, up to 240 MHz)
• Memory:
  • RA4M1- 256 kB Flash, 32 kB SRAM, 8 kB EEPROM (data flash)
  • ESP32-S3: 384 kB ROM, 512 kB SRAM
• Connectivity:
  • Wi-Fi: 802.11 b/g/n (Wi-Fi 4), up to 150 Mbps
  • Bluetooth: Bluetooth 5 LE
• I/O Capabilities:
  • 14 Digital I/O
  • 6 Analog Inputs
  • PWM: 6 pins
  • 1 DAC (12-bit)
  • UART, SPI, I²C, CAN (external transceiver needed)
• Power & Voltage:
  • Operating voltage: 5 V for RA4M1; ESP32-S3 runs at 3.3 V
  • Input (VIN or barrel jack): 6–24 V
  • I/O pins max DC current: 8 mA
• Physical Dimensions: 68.85 mm × 53.34 mm