#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define CHAR_WIDTH 6
#define CHAR_HEIGHT 7
#define NUM_COLUMNS (SCREEN_WIDTH / CHAR_WIDTH)

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

int rainDrops[NUM_COLUMNS]; // Store rain drop positions

void setup() {
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.print("Hello");
  display.display();

  randomSeed(analogRead(0));
  for (int i = 0; i < NUM_COLUMNS; i++) {
    rainDrops[i] = random(SCREEN_HEIGHT);
  }
}

void loop() {
  display.clearDisplay();

  for (int i = 0; i < NUM_COLUMNS; i++) {
    // Update rain drop position
    if (rainDrops[i] < SCREEN_HEIGHT) {
      display.setCursor(i * CHAR_WIDTH, rainDrops[i]);
      display.write(random(33, 123)); // ASCII characters from '0' ('48') to 'Z' ('90')
      rainDrops[i] += CHAR_HEIGHT; // Move down by one character
    } else {
      rainDrops[i] = 0; // Reset to top
    }
  }

  display.display();
  delay(50); // Adjust speed of falling effect
}