Improve LCD1602 demo animations

sketches/arduino-uno-r4-wifi/lcd1602_i2c_demo/README.md

@@ -5,8 +5,10 @@ PCF8574/PCF8574A I²C-backpack. Demoen viser:
 
 - animeret opstart og blink med baggrundsbelysningen;
 - brugerdefinerede hjerte-, smiley- og rakettegn;
-- vandret løbetekst;
+- tekstkort, der skifter på stedet uden vandret scrolling;
 - en animeret 16-kanals "BYTE BEATS"-equalizer;
+- en hoppende pixel, der udnytter displayets 80×16 individuelle pixelpositioner;
+- animeret digital "PIXEL RAIN" med dynamiske brugerdefinerede tegn;
 - oppetid og spinner.
 
 Sketchen bruger kun `Wire`, som følger med Arduino-kernen. Den scanner selv

sketches/arduino-uno-r4-wifi/lcd1602_i2c_demo/lcd1602_i2c_demo.ino

@@ -144,22 +144,24 @@ void bootSequence() {
   }
 }
 
-void marqueeDemo() {
+void messageCardsDemo() {
-  const char message[] = "   Arduino UNO R4 WiFi + LCD1602 = AWESOME!   ";
+  const char *cards[][2] = {
-  const int length = sizeof(message) - 1;
+    {" ARDUINO UNO R4", "  WIFI POWERED"},
+    {"  LCD1602+I2C", " PIXELS AT WORK"},
+    {"   CODE. MAKE.", "    REPEAT!"}
+  };
 
   lcdClear();
   lcdSetCursor(0, 0);
-  lcdWrite(0);
+  printPadded(" MAKER MODE");
-  lcdPrint(" MAKER MODE ");
+  delay(900);
-  lcdWrite(0);
 
-  for (int offset = 0; offset <= length - LCD_COLUMNS; ++offset) {
+  for (const auto &card : cards) {
+    lcdSetCursor(0, 0);
+    printPadded(card[0]);
     lcdSetCursor(0, 1);
-    for (uint8_t column = 0; column < LCD_COLUMNS; ++column) {
+    printPadded(card[1]);
-      lcdWrite(message[offset + column]);
+    delay(1350);
-    }
-    delay(145);
   }
 }
 
@@ -192,6 +194,89 @@ void equalizerDemo() {
   lcdCreateChar(2, rocket);
 }
 
+void bouncingPixelDemo() {
+  lcdClear();
+  lcdSetCursor(0, 0);
+  printPadded(" BOUNCING PIXEL");
+  lcdSetCursor(0, 1);
+  printPadded("     80x16");
+  delay(900);
+  lcdClear();
+
+  int x = 2;
+  int y = 2;
+  int dx = 2;
+  int dy = 1;
+  int previousColumn = -1;
+  int previousRow = -1;
+
+  for (uint8_t frame = 0; frame < 150; ++frame) {
+    if (previousColumn >= 0) {
+      lcdSetCursor(previousColumn, previousRow);
+      lcdWrite(' ');
+    }
+
+    byte pixel[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+    pixel[y % 8] = 1 << (4 - (x % 5));
+    lcdCreateChar(4, pixel);
+
+    int column = x / 5;
+    int row = y / 8;
+    lcdSetCursor(column, row);
+    lcdWrite(4);
+    previousColumn = column;
+    previousRow = row;
+
+    x += dx;
+    y += dy;
+    if (x <= 0 || x >= 79) {
+      x = constrain(x, 0, 79);
+      dx = -dx;
+    }
+    if (y <= 0 || y >= 15) {
+      y = constrain(y, 0, 15);
+      dy = -dy;
+    }
+    delay(35);
+  }
+}
+
+void pixelRainDemo() {
+  lcdClear();
+  lcdSetCursor(0, 0);
+  printPadded("   PIXEL RAIN");
+  lcdSetCursor(0, 1);
+  printPadded("  //////\\\\\\");
+  delay(900);
+
+  lcdClear();
+  for (uint8_t row = 0; row < LCD_ROWS; ++row) {
+    lcdSetCursor(0, row);
+    for (uint8_t column = 0; column < LCD_COLUMNS; ++column) {
+      lcdWrite((column + row * 3) % 8);
+    }
+  }
+
+  for (uint8_t frame = 0; frame < 55; ++frame) {
+    for (uint8_t slot = 0; slot < 8; ++slot) {
+      byte rain[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+      for (uint8_t pixelColumn = 0; pixelColumn < 5; ++pixelColumn) {
+        uint8_t head = (frame + slot * 3 + pixelColumn * 5) % 13;
+        if (head < 8) rain[head] |= 1 << (4 - pixelColumn);
+        if (head > 0 && head - 1 < 8 && ((slot + pixelColumn) & 1)) {
+          rain[head - 1] |= 1 << (4 - pixelColumn);
+        }
+      }
+      lcdCreateChar(slot, rain);
+    }
+    delay(80);
+  }
+
+  lcdCreateChar(0, heart);
+  lcdCreateChar(1, smile);
+  lcdCreateChar(2, rocket);
+}
+
 void uptimeDemo() {
   lcdClear();
   lcdSetCursor(0, 0);
@@ -239,7 +324,9 @@ void loop() {
     return;
   }
 
-  marqueeDemo();
+  messageCardsDemo();
   equalizerDemo();
+  bouncingPixelDemo();
+  pixelRainDemo();
   uptimeDemo();
 }