Arduino reads data from ky015 sensor and writes to serial in json format

TempAndHumidityKY015.c

int DHpin = 8; // input/output pin
byte dat[5];

byte read_data()
{
  byte i = 0;
  byte result = 0;
  for (i = 0; i < 8; i++) {
    while (digitalRead(DHpin) == LOW); // wait 50us
    delayMicroseconds(30); //The duration of the high level is judged to determine whether the data is '0' or '1'
    if (digitalRead(DHpin) == HIGH) result |= (1 << (8 - i)); //High in the former, low in the post
    while (digitalRead(DHpin) == HIGH);//Data '1', waiting for the next bit of reception
  }
  return result;
}

void start_test()
{
  digitalWrite(DHpin, LOW); //Pull down the bus to send the start signal
  delay(30); //The delay is greater than 18 ms so that DHT 11 can detect the start signal
  digitalWrite(DHpin, HIGH);
  delayMicroseconds(40); //Wait for DHT11 to respond
  pinMode(DHpin, INPUT);
  while(digitalRead(DHpin) == HIGH)
    delayMicroseconds(80); //The DHT11 responds by pulling the bus low for 80us;
  if(digitalRead(DHpin) == LOW);
    delayMicroseconds(80); //DHT11 pulled up after the bus 80us to start sending data;
  for(int i = 0; i < 5; i++) dat[i] = read_data();//Receiving temperature and humidity data, check bits are not considered;
  pinMode(DHpin, OUTPUT);
  digitalWrite(DHpin, HIGH); //After the completion of a release of data bus, waiting for the host to start the next signal
}

void setup()
{
  Serial.begin(9600);
  pinMode(DHpin, OUTPUT);
}

void loop()
{
  start_test();
  
  byte checksum = dat[0] + dat[1] + dat[2] + dat[3];
  if (dat[4] == checksum) {
    Serial.print("{\"h\":");
    Serial.print(dat[0], DEC); //Displays the integer bits of humidity;
    Serial.print('.');
    Serial.print(dat[1], DEC); //Displays the decimal places of the humidity;
    Serial.print(", \"t\":");
    Serial.print(dat[2], DEC); //Displays the integer bits of temperature;
    Serial.print('.');
    Serial.print(dat[3], DEC); //Displays the decimal places of the temperature;
    Serial.print("}\n");    
  }

  delay(4000);
}