Hello Everyone,
I have Mount HD44780 with arduino, and have done all connections according to given diagram (although i have practice many other configrations to check if i am doing it right but nothing works), my HD44780 display turns ON (as shown in the picture) but when i burn simple example of Hello world my Liquidcrystal library it displays nothing. so i decided to connect V0 pin with 10k potentiometer to check maybe the contrast was the issue but by rotating the nob it shows oly half gird as shown in picture. i am unable to figure out the problem? is my HD44780 led is not working properly?
Post your code. Read the forum guidelines to see how to properly post code. Use the IDE autoformat tool (ctrl-t or Tools, Auto format) before posting code in code tags.
Post photos of the wiring and the LCD.
Have you tried adjusting the contrast pot?
The correct way to wire the contrast pot is to wire one end of the pot to ground and the wiper to pin 3. The other end of the pot not connected. The long standing advice that the pot is wired to ground, Vcc and pin 3 is wrong. It is an error perpetuated over many years that begs correction.
i have run hello world program from liquidCrystal Example.
#include <LiquidCrystal.h>
//LiquidCrystal lcd(RS, E, D4, D5, D6, D7);
LiquidCrystal lcd(7, 8, 9, 10, 11, 12); // put your pin numbers here
void setup()
{
lcd.begin(16, 2); // put your LCD parameters here
lcd.print("hello, world!");
lcd.setCursor(0,1)
lcd.print("it works!");
}
void loop()
{
}
Have you tried adjusting the contrast pot?
yes i have tried and it shows only half blocks and within seconds its just fads away. you can see in image.
The correct way to wire the contrast pot is to wire one end of the pot to ground and the wiper to pin 3. The other end of the pot not connected. The long standing advice that the pot is wired to ground, Vcc and pin 3 is wrong. It is an error perpetuated over many years that begs correction.
I have tried it but the results are same. i shows only blocks for some thime and then they disappear.
Do you see a row of blocks on the top row of the LCD?
yes only half row of blocks, meaning 8 blocks in 1st row and 8 blocks in second row and it fads away within seconds.
The schematic shows how it should be wired. Post a readable schematic.
Photos of the actual wiring show how it is wired. Post photos of the actual wiring and LCD.
The half display is characteristic of a hardware problem on a 16x2 lcd where the auxiliary controller on the back of the display is not communicating with the primary hd44780 controller.
Very unlikely to be required indeed. Almost all of these "1602" displays have resistor "R8" as "101" or 100 Ohms.
Now note that the photo shows "blocks" in the right hand half of the display only, and on both rows. The contrast is clearly set correctly (irrespective of ow the potentiometer is wired )
This strongly suggests a faulty display as I do not know how it can be initialised in that manner.
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