I have been trying to make an LCD to work on my Arduino board and no matter what I do it always has the bottom row filled with white squares and the top row blank. I have tried multipl;e boards, swapping wires, rewiring many times, other LCD’s, other breadboards, and it does not work. My code is as follows:
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
lcd.print(millis() / 1000);
Any insight into this would be much appreciated.
EDIT: I used this diagram to wire it up:
Issues like this are almost always a wiring issue.
Post some photos of your board and wiring so we look at it and verify the wiring and check for any potential soldering issues.
The picture is a bit dark so some things are a bit hard to tall, like the pot and the exact position of the wires in the Arduino. There are some really dark shadows that look like black wires.
The pictures is cropped so the other half of the display is not visible.
One thing that you should check is the power rails. It is hard to tell in the photo, but it looks like the power
rail may not be a single rail all the way across. It kind of looks like there are blocks of 5 pins separated by a blank position.
Some bread boards are made that way and the individual blocks are not connected.
And some boards have blocks that are connected; however, the left and right side are not connected.
Check to see if is the case on your board.
If so you either need to use a single block, or use jumper wires to interconnect them.
Or use two columns in the main section for your "power rails".
If it isn't the power rails, can you post some additional photos taken in better light without using a flash so we can get a better view of things.
I tried that and although it did not fix the issue, it did result in a 7x2 grid of white boxes on startup a couple times. I tried to get a slightly better picture, sadly, I don't have many options of areas to get a good one so this was just under a desk lamp. It should be better though.
I see the ground wire that came unplugged. This happened during the picture and I plugged it back in, to no avail.
Much better photo. The wiring looks ok.
The soldering could use some touch up. There are several pins/holes that need have a bit more heat applied to get the solder to flow out better. With a proper solder connection you should not see any part of the hole in the PCB showing.
That ended up being the problem. Thank you! i was actually a bit worried that i had damaged it. Thanks again for your help!