my dht22 sensor fails to get readings.Iam powering esp32 from usbport.Is this a power issue?
Sometimes I observed problems with my ESP32 while powering it from PC USB port directly. Try power it from a USB hub powered by an external source. Also helps to replace the USB cable with a stronger and/or shorter one. Both helped for me. This is probably the easiest way to find out if there is a mistake in USB.
Now I use an external 5V power supply on my development board (DOIT ESP32 DEVKIT V1) via pin Vin. But of course, before doing this, check to see if your board allows such external powering to avoid the damage to the board.