Final - Bathroom fan relay

#include <TM1637.h> // include TM1637 libary "DigitalTube"
#include "DHT.h" // include dht libary
const int SO = 9; // setting pin 9 for trouble shooting
const int CLK = 2; // pin CLK is connected to
const int DIO = 3; // pin DIO is connected to
const int DHTpin = 5; // pin dht is connected to
#define DHTTYPE DHT11 // the type of DHT sensor
TM1637 tm1637(CLK,DIO); // initalize TM1637 to pin
DHT dht(DHTpin, DHTTYPE); // initalize dht to pin and type
const int relay = 4; // pin relay is on
void setup() {
  dht.begin(); // initalize dht
  tm1637.init(); // initalize tm1637
  tm1637.set(2); // set brightness of tm1637
  pinMode(relay, OUTPUT); // set relay pin as output
  pinMode(SO, INPUT_PULLUP); // setting TS pin as a input
  Serial.begin(9600); // start serial at 9600 baud
}
void loop() {
  int humidity = dht.readHumidity(); // set humidity to the sensor humidity reading
  int temp = dht.readTemperature(true); // set temp to temperature reading from sensor - true is added for Fahrenheit setting
  int d1t = temp / 10; // set d1t to first digit of temp
  int d2t = temp % 10; // set d2t to second digit of temp
  int d1h = humidity / 10; // set d1h to first digit of humidity
  int d2h = humidity % 10; // set d2h to second digit of humidity
  if (humidity >= 55) digitalWrite(relay, HIGH); // if humidity is at or over 55 turn on relay
  if (humidity <= 50) digitalWrite(relay, LOW); // if humidity is at or less than 50 turn off relay
  tm1637.display(0,d1t); // display first temp digit on segment 0
  tm1637.display(1,d2t); // display second temp digit on segment 1
  tm1637.display(2,d1h); // display first humidity digit on segment 2
  tm1637.display(3,d2h); // display second humidity digit on segment 3
  if (temp == 00 || humidity == 00) { // if sensor is showing 00 prints EEEE
    tm1637.display(0,14);
    tm1637.display(1,14);
    tm1637.display(2,14);
    tm1637.display(3,14);
  }
  if (digitalRead(SO) == LOW) { // if SO is high we will start a serial display
    Serial.println(" START DIAG SCREEN ");
    Serial.print(dht.readHumidity()); // read humidity data from sensor
    Serial.println(" Humidity from sensor ");
    Serial.print(humidity); // read humidity data from humidity
    Serial.println(" Humidity value stored ");
    Serial.print(dht.readTemperature(true)); // read temp from sensor
    Serial.println(" Temp from sensor ");
    Serial.print(temp); // read temp data from temp
    Serial.println(" Temp value stored ");
    Serial.print(digitalRead(relay)); // read if relay is high or low
    Serial.println(" Relay value ");
    Serial.print(digitalRead(SO)); // read if SO is high or low
    Serial.println(" SO value ");
    Serial.println(" END DIAG SCREEN ");
  }
  delay(60000); // 60 second delay
}