I changed fused bits, my program is getting uploaded but doesn't responds according to it. I have nextion display connected to it's tx3 and rx3 which does not get value from controller.here is my attached schematic and program.
2.ino (373 Bytes)
You say you have the Nextion connected to TX3 and RX3, which I take to be PJ1 and PJ0 (Serial3), but your sketch doesn't do anything with Serial3 other than initializing it. Your sketch only outputs data on Serial (PE1, PE0). From your schematic, it doesn't appear that you have anything connected to those pins.
Pj1 and PJ2 are connected to connector J14 where nextion display is connected on my PCB board
Hi,
Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html .
Then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.
Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Did you prove your custom board work properly before changing the fuse bit?
Why did you change fuse bits?
Did your code work before you changed fuse bits?
Tom.. 
meghabasnett:
Pj1 and PJ2 are connected to connector J14 where nextion display is connected on my PCB board
That does not match your schematic, in which you connect PJ0 (RXD3) and PJ1 (TXD3) to J14.