Temperature Monitor Using 4 Digit 7 Segment Display

/*
  Showing number 0-9 on a Common Anode 7-segment LED display
  Displays the numbers 0-9 on the display, with one second inbetween.
    A
   ---
  F |   | B
  | G |
   ---
  E |   | C
  |   |
   ---
    D
  This example code is in the public domain.
*/
#include <stdio.h> // other rules that are needed by the code that are being allowed by this statement
#include <dht.h> // the rules and values that the dht (digital-output, relative humidity, and temperature) sensor need
#define dht_apin A0 // the pin that Analog Pin sensor is connected to

dht DHT;

// Pin 2-8 is connected to the 7 segments of the display.

int SegA = 2;
int SegB = 3;
int SegC = 4;
int SegD = 5;
int SegE = 6;
int SegF = 7;
int SegG = 8;
int D1 = 13;
int D2 = 10;
int D3 = 11;
int D4 = 12;

// the setup routine runs once when you press reset:
void setup() {
  // initialize the digital pins as outputs.
  pinMode(SegA, OUTPUT);
  pinMode(SegB, OUTPUT);
  pinMode(SegC, OUTPUT);
  pinMode(SegD, OUTPUT);
  pinMode(SegE, OUTPUT);
  pinMode(SegF, OUTPUT);
  pinMode(SegG, OUTPUT);
  pinMode(D1, OUTPUT);
  pinMode(D2, OUTPUT);
  pinMode(D3, OUTPUT);
  pinMode(D4, OUTPUT);

  Serial.begin(9600);
  delay(500);//Delay to let system boot
  Serial.println("DHT11 Humidity & Temperature Sensor\n\n");
  delay(1000);//Wait before accessing Sensor
}//end "setup()"

// the loop routine runs over and over again perpetually:
void loop() {
  //Start of Program

  delay(100);
  DHT.read11(dht_apin);
  Serial.print("%  ");
  Serial.print("temperature = ");
  Serial.print(DHT.temperature);
  Serial.println("º Celcius  \n\n");

  int tempd1 = (int)((int)DHT.temperature / 10) % 10;
  int tempd2 = (int)DHT.temperature % 10;
  //Serial.print("t1 =");
  //Serial.println(tempd1);
  //Serial.println(tempd2);
  //disp_off();
  for(int i = 0; i<2000; i++){
  digitalWrite(D1, LOW);
  digitalWrite(D2, HIGH);
  digitalWrite(D3, HIGH);
  digitalWrite(D4, HIGH);  // turn on digit 1
  disp(tempd1);   //display digit 1 (most left)
  delay(1);
  digitalWrite(D1, HIGH);
  digitalWrite(D2, LOW);
  digitalWrite(D3, HIGH);
  digitalWrite(D4, HIGH);  // turn on digit 2
  disp(tempd2);   // display digit 2 (second most left)
  delay(1);
  
  digitalWrite(D1, HIGH);
  digitalWrite(D2, HIGH);
  digitalWrite(D3, HIGH);
  digitalWrite(D4, LOW);
  disp(10);   // display digit 2 (second most left)
  delay(1);
  }
  disp_off();

  //Wait 3 seconds before accessing sensor again.
  //This value can be changed but fastest should be once every two seconds.
}//end "loop()"
void disp(byte number) {
  //Serial.print("switch=");
  //Serial.println(number);
  switch (number) {
    case 0:  // print 0
      digitalWrite(SegA, HIGH);
      digitalWrite(SegB, HIGH);
      digitalWrite(SegC, HIGH);
      digitalWrite(SegD, HIGH);
      digitalWrite(SegE, HIGH);
      digitalWrite(SegF, HIGH);
      digitalWrite(SegG, LOW);
      break;

    case 1:  // print 1
      digitalWrite(SegA, LOW);
      digitalWrite(SegB, HIGH);
      digitalWrite(SegC, HIGH);
      digitalWrite(SegD, LOW);
      digitalWrite(SegE, LOW);
      digitalWrite(SegF, LOW);
      digitalWrite(SegG, LOW);
      break;

    case 2:  // print 2
      //Serial.println("printed 2");
      digitalWrite(SegA, HIGH);
      digitalWrite(SegB, HIGH);
      digitalWrite(SegC, LOW);
      digitalWrite(SegD, HIGH);
      digitalWrite(SegE, HIGH);
      digitalWrite(SegF, LOW);
      digitalWrite(SegG, HIGH);
      break;

    case 3:  // print 3
      digitalWrite(SegA, HIGH);
      digitalWrite(SegB, HIGH);
      digitalWrite(SegC, HIGH);
      digitalWrite(SegD, HIGH);
      digitalWrite(SegE, LOW);
      digitalWrite(SegF, LOW);
      digitalWrite(SegG, HIGH);
      break;

    case 4:  // print 4
      digitalWrite(SegA, LOW);
      digitalWrite(SegB, HIGH);
      digitalWrite(SegC, HIGH);
      digitalWrite(SegD, LOW);
      digitalWrite(SegE, LOW);
      digitalWrite(SegF, HIGH);
      digitalWrite(SegG, HIGH);
      break;

    case 5:  // print 5
      digitalWrite(SegA, HIGH);
      digitalWrite(SegB, LOW);
      digitalWrite(SegC, HIGH);
      digitalWrite(SegD, HIGH);
      digitalWrite(SegE, LOW);
      digitalWrite(SegF, HIGH);
      digitalWrite(SegG, HIGH);
      break;

    case 6:  // print 6
      digitalWrite(SegA, HIGH);
      digitalWrite(SegB, LOW);
      digitalWrite(SegC, HIGH);
      digitalWrite(SegD, HIGH);
      digitalWrite(SegE, HIGH);
      digitalWrite(SegF, HIGH);
      digitalWrite(SegG, HIGH);
      break;

    case 7:  // print 7
      digitalWrite(SegA, HIGH);
      digitalWrite(SegB, HIGH);
      digitalWrite(SegC, HIGH);
      digitalWrite(SegD, LOW);
      digitalWrite(SegE, LOW);
      digitalWrite(SegF, LOW);
      digitalWrite(SegG, LOW);
      break;

    case 8:  // print 8
      //Serial.println("printed 8");
      digitalWrite(SegA, HIGH);
      digitalWrite(SegB, HIGH);
      digitalWrite(SegC, HIGH);
      digitalWrite(SegD, HIGH);
      digitalWrite(SegE, HIGH);
      digitalWrite(SegF, HIGH);
      digitalWrite(SegG, HIGH);
      break;

    case 9:  // print 9
      digitalWrite(SegA, HIGH);
      digitalWrite(SegB, HIGH);
      digitalWrite(SegC, HIGH);
      digitalWrite(SegD, HIGH);
      digitalWrite(SegE, LOW);
      digitalWrite(SegF, HIGH);
      digitalWrite(SegG, HIGH);
      break;
    
    case 10:  // print 3
      digitalWrite(SegA, HIGH);
      digitalWrite(SegB, LOW);
      digitalWrite(SegC, LOW);
      digitalWrite(SegD, HIGH);
      digitalWrite(SegE, HIGH);
      digitalWrite(SegF, HIGH);
      digitalWrite(SegG, LOW);
      break;
  }
}
  void disp_off() {
    digitalWrite(D1, HIGH);
    digitalWrite(D2, HIGH);
    digitalWrite(D3, HIGH);
    digitalWrite(D4, HIGH);
}