In one of my applications, I have designed a controller with remaote keybord & display connected with each other by 15 core sheilded cable.
display-2x16 lcd keyboard-5x5 matrix membrane type.
The controller works fine.
My problem is I get some unknown letters on the display. Also some of the functions of key (such as program , stop) get energised even without pressing the key. This happens once in hour.
What should I do?