I tried 3 different sensor DHT11 but output is not changed. How can fix it ?
How is your DHT11 connected? A photo may be helpful.
Do you have a 3-pin or 4-pin sensor?
Is it a bare sensor (just the plastic case with leads), or one built on a tiny circuit board?
If a bare sensor, did you add the pull-up resistor? What value and how is it connected?