Is it ok to use two ground pins in arduino?

I'm utilizing two power sources... the one that comes from arduino (5V) and one 12V transformer to power my stepper motor. In the 5V pins I am powering up LCD display and my water level indicator.
Now, I utilized two ground pins for the two voltages (5v arduino, 12V) . At first I only used one ground for the two voltages because they need to be in a common ground but voltages are jamming together (i think) because every time 12v is on , the lcd (which is connected to 5V) isn't functioning well. So, I decided to use another ground from the arduino and connect it to my 12V source so it could still have a reference point to my 5V supply.
It worked , the LCD functions well but another problem has arised. The rectifier diodes in my 12V transformer gets really hot. What could be the problem? . Does it have anything to do with using two separate ground pins in my arduino?

rickharris1 year ago

sorry, this image

servo feed.jpg
rickharris1 year ago

ground on the Arduino is the same place no matter which pin you use.

If you draw too much current from the supply then the rectifier will get hot. Check the circuit and the current required by the servos.

your servo should be connected as in the diagram


Don't expect any useful answers....

Obviously you did not check your previous posting and felt the need for a new topic about the same problem.