LCD weird characters - Control relays from Arduino

Other Hardware Displays
1

Hi everyone,

I have already read simiral posts in forum but nothing can't solve my problem.

I have an arduino Uno, an LCD display with I2C communication, two 2-relay modules which are controlled from the arduino and an LM35 temperature sensor. The arduino is powered on with a 9V power supply. In this project arduino controls the 2 relay modules and prints the temperature in the LCD. The 2 relay modules control 3 large industrial relays in which 3 motors are connected. The problem is the following:

When the system is powered on, the relays οperate well and the temperature is printed in the LCD. After a small amount of time, in the LCD display is printed weird characters but the relays, both modules and industrials, continue to work well. I must mention that of the industrial relays are off of the project and have only the modules, the issue with the LCD doesn't appear. I believe that the industrial relays create the problem, but i don't know how to solve this. How can i solve this issue? Please, any solution can help.

2

I have already read simiral posts in forum but nothing can't solve my problem.

Did you narrow your search? There have been lots of recent posts about similar topics. Look for posts with LCD and either garbled characters, weird characters, strange characters or something similar in the heading.

Generally speaking the solution typically involves a capacitor across pins 1 and 2 of the LCD module. Try adding capacitor to the list of search terms as well.

Don