I connected two arduino to each other using pin 0 and 1 ( tx of one arduino to rx of other and GND to GND) Then I burnt the example " switch case 2 " (u have to press letter 'a' ,'b' 'c'... on keyboard to switch on LED at pin 13,12,11..) to one arduino. When I send 'a','b'... using serial monitor to 1st arduino ( one with the sketch) it works but when I use the other arduino for serial communication , it doesn't responds..
