Low-level manipulation of LED matrix on UNO R4 WiFi

[ptillisch]

Hi @grb.

@grb

how to manipulate the mode and value of the pins P002...P213?

You can use pinMode and digitalWrite if you like. The pins on the RA4M1 connected to the matrix are mapped to Arduino pins:

variants/UNOWIFIR4/variant.cpp

Here is a simple sketch to blink LED 1 in the matrix:

void setup() {}
void loop() {
  pinMode(35, OUTPUT);
  pinMode(31, OUTPUT);
  digitalWrite(35, HIGH);
  digitalWrite(31, LOW);
  delay(1000);

  pinMode(35, INPUT);
  pinMode(31, INPUT);
  delay(1000);
}

Or you can use use the lower level API from the Renesas FSP (which the "Arduino UNO R4 Boards" core is based on) if you prefer:

https://forum.digikey.com/t/theory-behind-the-arduino-uno-r4-wifi-12-x-8-led-display-matrix/43827#p-85635-how-can-i-directly-access-an-led-from-the-arduino-uno-r4-led-matrix-7