After setup function my code doesn't execute and the loop() don't start 
. Thanks In Advance.
Here is my code with which i have tried:
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
//#include <Fonts/FreeMonoBoldOblique12pt7b.h>
//#include <Fonts/FreeSerif9pt7b.h>
#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);
#define NUMFLAKES 10
#define XPOS 0
#define YPOS 1
#define DELTAY 2
#define LOGO16_GLCD_HEIGHT 16
#define LOGO16_GLCD_WIDTH 16
static const unsigned char PROGMEM logo16_glcd_bmp[] =
{ B00000000, B11000000,
B00000001, B11000000,
B00000001, B11000000,
B00000011, B11100000,
B11110011, B11100000,
B11111110, B11111000,
B01111110, B11111111,
B00110011, B10011111,
B00011111, B11111100,
B00001101, B01110000,
B00011011, B10100000,
B00111111, B11100000,
B00111111, B11110000,
B01111100, B11110000,
B01110000, B01110000,
B00000000, B00110000
};
#if (SSD1306_LCDHEIGHT != 64)
#error("Height incorrect, please fix Adafruit_SSD1306.h!");
#endif
void setup() {
Serial.begin(9600);
// by default, we'll generate the high voltage from the 3.3v line internally! (neat!)
display.begin(SSD1306_SWITCHCAPVCC, 0x3C); // initialize with the I2C addr 0x3D (for the 128x64)
// init done
// Show image buffer on the display hardware.
// Since the buffer is intialized with an Adafruit splashscreen
// internally, this will display the splashscreen.
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(10, 0);
display.clearDisplay();
display.println("Welcome TO Access Control System");
display.display();
delay(2000);
display.clearDisplay();
// invert the display
display.invertDisplay(true);
delay(1000);
display.invertDisplay(false);
delay(1000);
display.clearDisplay();
// draw a bitmap icon and 'animate' movement
}
void loop() {
while (1) {
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(10, 0);
display.clearDisplay();
display.println("Welcome To Access Control System");
printText();
}
}
void printText(void) {
String s, p1, pc;
if (Serial.available())
{
display.println("Input Your Password:");
s = Serial.readString(); //getting string input in variable "s"
display.println("Type Again:");
pc = Serial.readString();
p1 = s;
if (p1 == pc) {
display.println("Password Matched...");
display.println("\n");
display.println("Confirm?");
display.println("Continue?");
char ch;
display.println("Confirm?");
ch = Serial.read();
if (ch == 'y') {
display.println("Input Your Password:");
s = Serial.readString(); //getting string input in variable "s"
p1 = s;
if (p1 == s) {
display.println("Accesses Granted Please Poceed");
while (1) {
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(10, 0);
display.clearDisplay();
display.println("input:");
printText();
}
if(ch == 'n') {
display.println("TRY AGAIN!!! THANK YOU");
}
// display.println(s);
}
display.display();
}
delay(1);
}
}
}