LCD not giving desired output

I am learning Arduino and I was making one program which will print "Hello" to the lcd display connected to arduino.
I dont know what is wrong but the LCD is not showing desired output, rather shows special characters and when I increase/decrease the contrast of lcd using the Potentiometer, the characters changes everytime.
my code is:

// include the library code:
#include <LiquidCrystal.h>

// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("hello");
}

void loop() {
// set the cursor to column 0, line 1
// (note: line 1 is the second row, since counting begins with 0):
lcd.setCursor(0, 1);
// print the number of seconds since reset:
lcd.print(millis() / 1000);
}


Please help.

1 Answer
1

Check what kind of lcd you are using.

Some lcd's come with the pin numbering reversed. IE the location of the 16 pins is on the top left corner, but instead of starting with pin number 1, the lcd starts with pin number 16.

Since the format of the LCD pins is the same both way (GND, VCC, input * 14, vcc, Gnd) it does not cause shorting problems, But the control signals are sent to the data pins, and the data signals are sent to the control pins.

I got this hint from the fact that changing the brightness changes the characters. If I am right, changing the contrast via the potentiometer will do you no good with respect to the actual contrast.

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