When I have tried interfacing my 16*2 LCD with Arduino I am getting only the black coloured boxes on my screen. What might be the problem?

Is there any solution to that? Do I need to connect any additional physical device to avoid that situation?

product is here lcd display 16*2

  • 2
    Hello and welcome to arduino.stackexchange. Your problem is a common one and relates to the contrast settings. PIN3 of your LCD needs a potentiometer which will allow you to change the contrast. – smajli Mar 22 '19 at 8:36
  • You should post a picture of the LCD, name the library you are using to interface it, and post your code that initializes it and attempts to send data to it. – Duncan C Mar 22 '19 at 13:13

There are two possible problems, and you haven't stated which it is.

  1. A single row of blocks (just the top row)

This is caused by either bad communication (wrong wiring) or incorrect code. Basically, the display isn't being initialized properly by your code for whatever reason.

  1. Two rows of blocks (the entire display full of blocks)

The display is being initialized properly, so both your code and wiring are correct. However, the contrast setting of the display is wrong. You need to check the wiring for your contrast potentiometer and adjust as necessary.

  • +1 on the contrast comment. – dandavis Mar 22 '19 at 19:36

it's very unusual for the lcd being faulty. since there is no pic that shows how you have connected the lcd i cannot say anything. however you can search "dronebot workshop lcd" on YouTube. Mr Bill had explained it very well he also shows how you can control the lcd by only four wires. go and see that video.

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