I want to control the room temperature automatically without remote contol.saya already follow tutrorial of Smarter Office: Automatic control of A/C | Poin2 Blog
but have not been successful ..
there anything you can help me
Its likely you will get more help if you give more detail about your problem.
Are you able to measure the correct temperature with the LM35?
Are you able to collect the IR codes from the existing controller? Are they consistent?
Are you actually sending IR codes? You can sometimes 'see' the output of an IR LED using a digital camera.
Is there any visible response from the AC unit when your arduino sends IR codes?