4 Digit 7 Segment Thermometer Help

Hi Guys,

So I decided I was going to start learning how to use 7 Segment Displays and shift registers. I am using a 74HC595 to control the anodes of a 4 digit 7 segment display. And 2N3904s for the Cathodes. and a Dallas DS18B20 temperature sensor.

However, I am having extreme flicker/timing issues with the display. here is the code I am using. Instead of the display normally updating it cycles through each Digit with a about one second delay before displaying the next digit. So it displays one digit at a time. I have read that DallasTemp library causes delays. But the display shouldn't have large delays in between numbers? So I am slightly confused. Can anyone help me out?

Thanks,

Austin

/*
* created by Rui Santos, http://randomnerdtutorials.com
* Temperature Sensor Displayed on 4 Digit 7 segment common anode
* 2013
*
* Modified by Austin Pauley for use with DS18B20
* 2015
*/


#include <OneWire.h>
#include <DallasTemperature.h>


#define ONE_WIRE_BUS A0
OneWire ds(ONE_WIRE_BUS);
DallasTemperature sensors(&ds);
DeviceAddress insideThermometer;


const int digitPins[4] = {
  5,4,3,2};                 //4 common anode pins of the display
const int clockPin = 11;    //74HC595 Pin 11 
const int latchPin = 12;    //74HC595 Pin 12
const int dataPin = 13;     //74HC595 Pin 14
const byte digit[10] =      //seven segment digits in bits
{
  B11000000, //0
  B11111001, //4
  B10100100, //2
  B10110000, //3
  B10011001, //4
  B10010010, //5
  B10000010, //6
  B11111000, //7
  B10000000, //8
  B10010000  //9
};
int digitBuffer[4] = {
  0,0,0,0};
int digitScan = 0, flag = 0, soft_scaler = 0;
;
float  tempC, tempF;


void setup(){
  for (int i = 0; i<4; i++)
  {
  pinMode(digitPins[i], OUTPUT);
  }
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
  sensors.begin();
  sensors.getAddress(insideThermometer, 0);
  Serial.begin(9600);
  sensors.setResolution(9);

}




void updateDisp(){
  for (byte j = 0; j < 4; j++)
  digitalWrite(digitPins[j], LOW);
  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, MSBFIRST, B11111111);
  digitalWrite(latchPin, HIGH);


  delayMicroseconds(100);
  digitalWrite(digitPins[digitScan], HIGH);


  digitalWrite(latchPin, LOW);


  shiftOut(dataPin, clockPin, MSBFIRST, digit[digitBuffer[digitScan]]);


  digitalWrite(latchPin, HIGH);
  digitScan++;
  if (digitScan>3) digitScan = 0;



}


float getTemp()
{
sensors.requestTemperatures();
tempF = sensors.getTempF(insideThermometer);
}
void loop(){
  int temp = (int)getTemp();


  digitBuffer[3] = int(temp) / 1000;
  digitBuffer[2] = (int(temp) % 1000) / 100;
  digitBuffer[1] = (int(temp) % 100) / 10;
  digitBuffer[0] = (int(temp) % 100) % 10;
  updateDisp();

}