displaying boxes in bottom row

i just brough a new lcd JHD 162A and uploaded hello world example.it is displaying boxes in the bottom row.

I have several of those displays. That is the way they work.

that box is where the character is displayed.

I assume that you are seeing a single row of boxes instead of the desired text. That would mean that your display is upside down and that it is not being properly initialized.

We will need more information in order to help you. Specifically we need to see your actual code and we also need to know how you intended to connect your display to your Arduino. If this was a parallel connection with seven wires we need a photograph of your actual connections. If it was an I2C connection with four wires then we need to know what library you are using.

Don

Ok Buddy, recheck you wiring on the LCD and UNO. This happened to me too, I was one pin off on the LCD wiring. Every pin. I was using the breadboard. good luck!

#include <LiquidCrystal.h>

LiquidCrystal lcd(7, 8, 9, 10, 11 , 12);

void setup() {
lcd.begin(16, 2);
lcd.setCursor(0,1);
lcd.write("PhanNominal: ");
}

void loop() { }