How to manually change orientation of iPad

Solution 1:

You can turn on "Assistive Touch," and go to device, then rotate, Then choose the orientation. Before you turn assistive touch off (if you DO want to turn it off, the black square on your screen can get in the way) you should lock orientation, just do it how the other user who answered said.

Solution 2:

Seems like you have issue with the gyroscope inside the iPad. He's the one detecting when the iPad is turned.

Your better chance would be to go to an Apple Store if it's still under guaranty, maybe they'll find a problem and change it for you.

To answer your question, no, there's no hardware button to change the orientation. But you can lock it, and here's the 2 possibilities. If under Settings • General • Use Side Switch to

• Lock Rotation
  Just flip the switch over the volume button to lock the iPad in it's current orientation.

• Mute
  Double-click the Home button, slide the apps to the right and click the button to the further left. It will lock the orientation.