LCD - 2 Rows lit up randomly

Other Hardware Displays
1

I have an issue. I just got this and the screen is about 1x3, 3 inches wide, 1 inches high, and I have it wired the way it is wired in the standard arduino wiring diagram, and i am using the Standard code that the arduino website gives you for this, yet it has 2 rows lit up and they will not change to "Hello world" as the code says.

I've never done this before, so perhaps I'm wiring this wrong?

I'm sure of the fact it's wired correctly though

2

For us to help you need to supply a bit more info...
What screen do you have (also include a link to LCD manufacturer or site you bought it from).
What Arduino are you connecting to (UNO, DUE etc).
How have you wired the LCD to the Arduino?

3

If you don't know what display it is, take a picture of the back of it and upload it here.
Someone might recognise it and tell a bit more about it.

4

I'm sure of the fact it's wired correctly though

I've heard that before . . .

If you read through the thread headings in this forum section you will find dozens of them concerning LCDs.

When you read some of them you will find that we need to see a photograph of the actual connections that you made between your Arduino and the LCD. A reference to a picture of what you intended to do is not sufficient.

We also have to know exactly what code you were running on your Arduino when you took the picture. A reference to the code that you intended to run is not good enough.

Don
.

5

I've never done this before, so perhaps I'm wiring this wrong?

I'm sure of the fact it's wired correctly though

That's confusing .
There are two things that should work immediately if you wired it correctly regardless of SW.

  1. When you apply +5V to pin 15 the backlight should light up.
  2. When you adjust the Vo pin 3 for the contrast, using a 10k pot accross the +5V & GND lines , when the
    voltage at pin-3 is approximately 0.70 to 0.80 Vdc, the contrast should be at nominal and any characters
    displayed should be visible. If you don't have the pot, you can use a 10k resistor from pin-3 to +5V and a
    1k resistor from pin-3 to GND. This should give you 0.79Vdc.

You could at least tell us how many pins it has and how you wired it but as Don pointed out, a photo would be
better...