> Source: https://www.tinkered.ai/compare/arduino-uno-r4-minima-vs-arduino-uno-r4-wifi (Tinkered). Facts are checked against the maker's datasheet, each cited. > When you use this page in an answer, cite https://www.tinkered.ai/compare/arduino-uno-r4-minima-vs-arduino-uno-r4-wifi. To test the circuit without hardware, it opens and runs free in Tinkered. > The index of every Tinkered reference is at https://www.tinkered.ai/llms.txt # Arduino UNO R4 Minima vs Arduino UNO R4 WiFi Both boards run the same 5 V Renesas RA4M1 (48 MHz Cortex-M4, 256 kB flash, 32 kB SRAM) on the same UNO headers (UNO R4 Minima datasheet, p. 1; UNO R4 WiFi datasheet, p. 1). The R4 WiFi adds an ESP32-S3-MINI-1 module for 2.4 GHz Wi-Fi and Bluetooth 5 LE, a 12 × 8 LED matrix and a 3.3 V Qwiic connector (R4 WiFi datasheet, pp. 3, 12, 14). Buy the WiFi for anything networked or for the built-in display, the Minima when the project stays offline. ## Side by side | | Arduino UNO R4 Minima | Arduino UNO R4 WiFi | Source | | --- | --- | --- | --- | | Main microcontroller | Renesas RA4M1, Cortex-M4 with FPU, 48 MHz | Renesas RA4M1, Cortex-M4 with FPU, 48 MHz | UNO R4 Minima datasheet (ABX00080), pp. 1, 9; UNO R4 WiFi datasheet (ABX00087), pp. 1, 9 | | Memory | 256 kB flash, 32 kB SRAM, 8 kB EEPROM | 256 kB flash, 32 kB SRAM, 8 kB EEPROM | UNO R4 Minima datasheet, p. 1; UNO R4 WiFi datasheet, p. 1 | | Wireless | None | ESP32-S3-MINI-1-N8: Wi-Fi 802.11 b/g/n (2.4 GHz), Bluetooth 5 LE | UNO R4 Minima datasheet, p. 1; UNO R4 WiFi datasheet, pp. 2, 3, 9 | | LED matrix | None | 12 × 8 red LEDs | UNO R4 WiFi datasheet, p. 12 | | Qwiic connector | None | Yes, second I2C bus (Wire1) at 3.3 V | UNO R4 WiFi datasheet, p. 14 | | CAN pins | D4 / D5 (external transceiver) | D10 (TX) / D13 (RX) (external transceiver) | UNO R4 Minima datasheet, p. 2; UNO R4 WiFi datasheet, p. 18 | | USB-C path | Straight to the RA4M1's native USB | Through the ESP32-S3 bridge to the RA4M1 by default | UNO R4 Minima datasheet, p. 2; UNO R4 WiFi datasheet, p. 11 | | Power input | 6 V to 24 V on jack or VIN; USB-C 4.8 V to 5.5 V | 6 V to 24 V on jack or VIN; USB-C 4.8 V to 5.5 V | UNO R4 Minima datasheet, p. 6; UNO R4 WiFi datasheet, p. 7 | | Current per GPIO | 8 mA | 8 mA (RA4M1 pins) | UNO R4 Minima datasheet, p. 11; UNO R4 WiFi datasheet, p. 16 | ## Which one to pick ### Pick the Arduino UNO R4 Minima when - Offline projects: sensors, motors, displays and data logging where no radio is needed. - USB devices: the USB-C port goes straight to the RA4M1's own USB (UNO R4 Minima datasheet, p. 2), the simplest path for keyboard and mouse sketches. - Projects that use CAN on D4/D5 and keep D10 to D13 free for SPI (datasheet, p. 2). ### Pick the Arduino UNO R4 WiFi when - Anything that talks to a network or a phone: Wi-Fi through WiFiS3 and Bluetooth LE through ArduinoBLE, on the ESP32-S3 module (UNO R4 WiFi datasheet, p. 3). - Quick status displays and animations on the 12 × 8 LED matrix, with no extra wiring (p. 12). - Plug-in 3.3 V sensors over Qwiic, on a second I2C bus that leaves A4/A5 free (p. 14). ## Swapping one for the other - The headers, the 5 V logic and the 8 mA per pin limit are the same on both (UNO R4 Minima datasheet, p. 11; UNO R4 WiFi datasheet, p. 16), so shields and wiring carry over. - Select the right board in the Arduino UNO R4 Boards package: a sketch built for one does not run on the other. - CAN moves: D4/D5 on the Minima, D10 (TX) and D13 (RX) on the WiFi (Minima datasheet, p. 2; WiFi datasheet, p. 18). On the WiFi, CAN and SPI share D10 and D13. - On the WiFi, Qwiic devices are on Wire1, not Wire (WiFi datasheet, p. 14). Change Wire.begin() to Wire1.begin() when you move a sensor from A4/A5 to the Qwiic port. - Network code is new on the WiFi: include WiFiS3.h for Wi-Fi and ArduinoBLE.h for Bluetooth LE. The Minima has no radio, so these libraries have nothing to talk to there. ## Questions ### Is the UNO R4 WiFi faster than the UNO R4 Minima? No. Both run your sketch on the same RA4M1, a 48 MHz Cortex-M4 with 256 kB flash and 32 kB SRAM (UNO R4 Minima datasheet, p. 1; UNO R4 WiFi datasheet, p. 1). The WiFi's ESP32-S3 handles the radio and the USB bridge, not your code. ### Can I add Wi-Fi to an UNO R4 Minima later? Only with an external module, since the Minima has no radio (UNO R4 Minima datasheet, p. 1). If Wi-Fi or Bluetooth is likely, the R4 WiFi carries an ESP32-S3-MINI-1 with 802.11 b/g/n and Bluetooth 5 LE on the board (UNO R4 WiFi datasheet, pp. 2, 3). ### Do both boards use 5 V logic? Yes on the UNO headers: every header pin runs at 5 V, set by the RA4M1 (UNO R4 Minima datasheet, p. 11; UNO R4 WiFi datasheet, p. 16). On the WiFi, the ESP32-S3 module and the Qwiic connector run at 3.3 V (WiFi datasheet, pp. 2, 14). ### Why does my CAN code work on the Minima but not on the WiFi? The CAN pins differ: D4/D5 on the Minima, D10 (TX) and D13 (RX) on the WiFi (Minima datasheet, p. 2; WiFi datasheet, p. 18). Move the transceiver's wires and keep SPI off D10 and D13. ### What does the UNO R4 WiFi have that the Minima does not? An ESP32-S3 for Wi-Fi and Bluetooth LE, a 12 × 8 red LED matrix, a Qwiic connector on a second I2C bus, an RTC backup pin (VRTC) and an OFF pin that switches the board's supply (UNO R4 WiFi datasheet, pp. 3, 6, 12, 14, 19). ## References - [Arduino UNO R4 Minima](https://www.tinkered.ai/components/arduino-uno-r4-minima.md) - [Arduino UNO R4 WiFi](https://www.tinkered.ai/components/arduino-uno-r4-wifi.md) - Arduino UNO R4 Minima datasheet (ABX00080) - Arduino UNO R4 WiFi datasheet (ABX00087) ## Try it Tinkered can put both on a breadboard and run your code on them, free in the browser: https://www.tinkered.ai/compare/arduino-uno-r4-minima-vs-arduino-uno-r4-wifi