LCD screen showing black squares in the first row

Hi guys,

Just wondering where I went wrong with the circuit setup. The LCD shows only black squares when I plug plus the Arduino USB to my laptop. I tried everything possible but still same results. The potentiometer I currently have is only adjusting the contrast of the black squares showing up, nothing else. This setup I used is from this YouTube video

I can’t seem to upload the image here. How should I convert it to JPG?

A good photo of your wiring and your code would help us help you.

I can’t seem to upload the image here. How should I convert it to JPG?

Well, in what form is it now?

Just use the attachment option and we can figure it out. We (obviously) need to see your assembly to figure out why the tutorial worked but yours did not. If you take photos, take it outside in full daylight but not direct sun, and preferably use a proper camera with optical zoom.

One warning - test all your Chinese jumper wires by connecting them back and forth on the breadboard so they form a chain, then use a LED and series resistor - or the backlight of your LCD - to verify they are all actually connected.

Speaking of the LCD - you must have the pin header actually connected to the 16 solder pads.

Just by the way, do not connect the potentiometer to 5 V - Vcc - this is a long-standing blunder in just about all the designs and tutorials. It will of course not prevent the display working (because they have worked so far :grinning: ), but it makes setting the contrast much easier if you do not connect it to 5 V and then even easier still if you use a 1k pot.