Arduino UNO R4 Minima and WiFi boards powered by a Renesas RA4M1 32-bit Arm Cortex-M4F microcontroller and equipped with an optional ESP32-S3 WiFI & BLE module are now available for respectively $20 (18 Euros) and $27.50 (25 Euros) on the Arduino store.
The Arduino UNO R4 Renesas RA4M1 board was initially unveiled during Arduino Day with most details, but not everything as the company had hidden one part of the board which we now know is for a 12×8 LED matrix and a Qwiic connector for expansion present on the UNO R4 WiFi only.
Arduino UNO R4 specifications:
- Microcontroller – Renesas RA4M1 Arm Cortex-M4F MCU @ 48 MHz with 32KB SRAM, 256KB flash
- Wireless (Arduino UNO R4 WiFi only) – ESP32-S3-MINI-1 module based on ESP32-S3 dual-core Xtensa LX7 microcontroller with 512KB SRAM, 384KB ROM, WiFi 4 and Bluetooth 5.0 connectivity, PCB antenna
- Display (UNO R4 WiFi only) – 12×8 LED matrix
- USB – 1 x USB Type-C port for power and programming
- Expansions
- Arduino UNO headers with Pins
- 14x digital I/Os
- 13x LED pins
- Analog – 6x analog input pin, 12-bit analog DAC
- 6x PWM
- 1x UART, 1x I2C, 1x SPI
- CAN Bus support
- I/O Voltage – 5V
- DC Current per I/O pin – 8 mA
- Arduino UNO R4 WiFi only
- Qwiic I2C connector for expansion modules.
- 3-pin header with an “OFF” pin to turn off the board and a “VRTC” pin to keep the internal Real-Time Clock powered and running.
- Arduino UNO headers with Pins
- Debugging and programming – 6-pin ICSP header; Arduino UNO R4 Minima only: 10-pin SWD header
- Misc – Reset button, Power LED
- Input voltage – 6 to 24V via a power barrel jack or Vin, 5V via USB-C port
- Dimensions – 68.6 x 53.4mm
Both Arduino UNO R4 boards retain hardware compatibility with the UNO form factor and 5V operating voltage meaning you can keep using existing shields. They also add HID support to emulate a mouse and/or keyboard, and the WiFi model also implements an error-catching mechanism that detects runtime crashes – such as a division by zero – and provides detailed explanations and hints about the code line causing the crash.
Arduino has already been ported to the Renesas RA4M1 microcontroller, and you’ll find detailed hardware and software documentation and example projects for both the Arduino UNO R4 WiFi and Minima on the documentation website, including for the use of new features such as WiFi and USB HID.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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Another detuned PCB antenna … They should read the ESPxx Design Guidelines, and have a look at the Olimex relais board.
Is there an issue here only if there is a ground plane below the antenna, or is it a problem even if the antenna is only located above the PCB material itself, with no metal traces below it?
The guidance allows for it to be above PCB material, though that’s not ideal. Having ground below it is horrible. Having the power and other connectors to the sides is also an issue–as is the assiciated ground plane those connections bring.
The minima variant looks okay. I don’t know much about the chip they picked, but I have aquired a relatively negative view of that manufacturer. The specs look okay, though.
The Wifi variant looks stupid. Bad RF module placement (and the RF module itself is a vastly better chip to program), stupid LED array, strange choice of layout….
If we see some decently cheap clones of the minima, this might catch on. If we’re at the $60/board range that the Arduino.cc people seem to expect, this board is DOA.
Maybe I did not clearly understand the last part of your comment, but with regard to price, it’s $20 for the Minima, $27.50 for the WiFi version.
Sorry, other sites were reporting much higher prices.
Renesas is pretty nice, I have used their S7G2 and it is very nice stuff but for this price, they are certainly skimping on the MCU, for me it speaks a lot of how they can add an ESP32, LED array and a lot of stuff for barely $7 while the bare minimum with the Renesas MCU is $20.
The RA4M1 seems just well, the low end of what Renesas offer and they should have chosen something a bit better for that price. As an example, I got a TM4C129 board for $30 and well, it just offers much more, there are some that are a bit cheaper too.
Kinda funny how the faster MCU is basically just a coprocessor for the Wifi board. ESP do suffer from drawbacks like high power consumption and bad peripherals but this one has a ESP and another MCU so the power consumption won’t be good while the Renesas peripherals aren’t even that good(unlike the more expensive ones from them).
So it takes an ESP32 and just use it as a wifi. WTF?
Exactly. Why do you need the lower processor? Just use a single dual core ESP32. Durant make any sense.