The Arduino UNO R4 Minima and the Arduino UNO R4 WiFi. ... the UNO R4 WiFi introduces a built-in 12×8 LED matrix, a Qwiic connector, and a VRTC and OFF pin. ...

Here is ‘blink’ modified to work TXLED and RXLED as well as LED-BUILTIN. int RXLED = 17; // The RX LED has a defined Arduino pin int TXLED = 30; // The TX LED has a defined Arduino pin // the setup ...