problem with DHT11 returning 21 bits instead of 41 ...

Other Hardware Sensors
2

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void loop()
{
    int pin = 2;
    int highs[42];
    pinMode(pin, OUTPUT);
    digitalWrite(pin, LOW);

    delay(10);  <<<<< should be at least 18 ms !!!! See figure 3 page 6

    digitalWrite(pin, HIGH);

    delayMicroseconds(30);  <<< should be 20-40 msec, OK I guess

    pinMode(pin, INPUT);
    for (int i=0; i<41; i++)   [color=red] // there are 41 pulses 0..40   not 42 ! [/color]
    {
        highs[i] = pulseIn(pin, HIGH);
    }
}

That said, you correctly detect the 80 mu pulse. and the other pulses

you have filled the array highs[]; now you need code to convert this to bytes, would look something like this partial code

byte RHI;
byte RHD;
byte TI;
byte TD;
byte CRC;
for (int i=1; i< 9; i++)
{
  RHI = RHI * 2;
  if (highs[i] > 50)  RHI = RHI + 1;  // add a one bit;  in short RHI++;
}
for (int i=9; i< 17; i++)
{
  RHD = RHD * 2;
  if (highs[i] > 50)  RHD = RHD + 1;  
}
for (int i=17; i< 25; i++)
{
  TI= TI* 2;
  if (highs[i] > 50)  TI = TI + 1;  
}
for (int i=25; i< 33; i++)
{
  TD= TD * 2;
  if (highs[i] > 50)  TD= TD+ 1;  
}
for (int i=33; i< 41; i++)
{
  CRC= CRC * 2;
  if (highs[i] > 50)  CRC= CRC + 1;  
}
Serial.println(RHI, DEC);
Serial.println(RHD, DEC);
Serial.println(TI, DEC);
Serial.println(TD, DEC);
Serial.println(CRC, DEC);