🛠 Blink on the UNO R4 Minima: your first 32-bit UNO

Goal

Flash the onboard LED of the UNO R4 Minima (Arduino AG, released June 2023, board P/N ABX00080) and understand why this is the first 32-bit UNO: a Renesas RA4M1 Cortex-M4 running at 48 MHz with 256 KB of flash and 32 KB of SRAM, against 16 MHz / 32 KB / 2 KB on the AVR Uno R3.

Hardware

• 1 UNO R4 Minima + a USB-C data cable (first UNO with USB-C)
• PC with Arduino IDE or arduino-cli

Code

const uint8_t LED = 13;   // onboard LED marked "L"

void setup { pinMode(LED, OUTPUT); }

void loop {
  digitalWrite(LED, HIGH);
  delay(500);
  digitalWrite(LED, LOW);
  delay(500);
}

In the IDE, install the "Arduino Renesas Uno Boards" platform, select board Arduino UNO R4 Minima, pick the COM port and upload.

Expected result

The L LED blinks every 0.5 s and keeps running on barrel-jack power alone (6-24 V accepted): the sketch lives in flash.

Common mistakes

• Wrong board selected: UNO R4 WiFi is a different target ; the plain Minima has no ESP32-S3 radio.
• Charge-only USB-C cable: no data, no port.
• Forgetting the 8 mA per-pin current limit before attaching external LEDs or sensors.