I am using Arduino Mega 2650. Interfacing an LCD with it works fine. But as soon as I connect a 5V DC relay's power supply from arduino, LCD starts showing garbage values.
Please help me out.
Please tell me what is the problem and how can I resolve it.
There are lot's of threads on this topic in the 'Displays' section of the forum. Search for topics headings that include the terms LCD and Garbage.
The inductance of relay is probably messing up the power supply. The best solution would be a separate power supply for the relay. You might get away with some filtering involving a capacitor or two.