serial_monitor.cpp

#include <M5StickC.h>
#define LGFX_AUTODETECT
#include <LovyanGFX.hpp>

static LGFX gfx;

void setup() {
  M5.begin();

  gfx.init();
  gfx.setRotation(1);
  gfx.fillScreen(TFT_BLACK);
  gfx.setTextColor(TFT_WHITE, TFT_BLACK);
  gfx.setFont(&fonts::lgfxJapanGothic_16);
  gfx.setBrightness(100);
  gfx.setTextSize(1);
  gfx.setCursor(0, 0);
  gfx.setTextScroll(true);
  gfx.setScrollRect(0, 0, gfx.width(), gfx.height());

  Serial.begin(9600);
}

void loop() {
  M5.update();
  if (Serial.available()) {
    int inByte = Serial.read();

    if (inByte == '\r')
      gfx.print("\n");
    else
      gfx.printf("%c", inByte);
  }
}