#define test_width 16
#define test_height 7
const unsigned char test_bits[] PROGMEM = { // https://en.wikipedia.org/wiki/X_BitMap
  0x13, 0x00, 0x15, 0x00, 0x93, 0xcd, 0x55, 0xa5, 0x93, 0xc5, 0x00, 0x80, 0x00, 0x60
};

#include <U8g2lib.h> // https://github.com/olikraus/u8g2/wiki
U8G2_SSD1306_72X40_ER_F_HW_I2C u8g2(U8G2_R0, U8X8_PIN_NONE);  // https://github.com/olikraus/u8g2/wiki/u8g2setupcpp

void setup() {
  u8g2.begin();
  u8g2.clear();
}

void loop() {
  u8g2.clearBuffer();
  u8g2.drawXBMP(random(72 - (5 * 5)), random(40 - 8), test_width, test_height, test_bits);
  u8g2.sendBuffer();
  delay(100);
}