I rely need help, i can't solve my issue with 20x4 lcd.
I trying to command one board with 2 relays, board is with optocuplers and is power from different supply.
Also I read an input from one ambient thermostat, and base on sensors read I'm trying to command 2 relays.
Everything works perfect without LCD, On LCD sometimes appears some noise.
I tried different solution, I installed also 2 capacitors (100micro and 100n) on display, but without success.
If some one have any clue I will by very grateful.
Please see picture from http://www.studio72.ro
Thanks in advance