My LCD is not printing anything and my serial monitor is blank. I'm getting very frustrated, please help me

That is the exact code I've been using, Tom

Hi,
Can you please check your wiring at the display, even though there is some parallax error, your connections do not look lined up to the correct pins.

It looks like you have connections to D0 and D1, there aren't any in the circuit diagram.
I count 7 wires lined up from pin1, but the circuit shows only 6.

const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;

Thanks.. Tom... :smiley: :+1: :coffee: :australia:

изображение
display damaged

you wiring is wrong.
start new.
post a clear list
LCD-Pin - Arduino-Pin - color

use red for VCC
use black for GND
use other colors for the other pins.

post new pictures and ensure we can identify each wire.

Correct - I have just come back to this thread and noted that.

At this point we do not know whether the present more general problem is a fault in the display module, in the wiring (always need to test all of those jumper leads as they may be faulty) or the code, which I have not looked at as it has not been posted in the preferred manner.

The apparent display fault is in the connections between HD44780 (emulation) chip and the display. It may simply be a problem in the "Zebra" strips, but that is another matter. In any case the problem is that the "HD44780" is not responding to the code so either the code is wrong (but probably not as it is difficult to get the cut-and-pasted code wrong with the module directly connected to the Arduino) or there is a bad connection between Arduino and HD44780 which includes the jumper wires and the tracks on the LCD module. I suppose there is some argument that if there is a fault in the PCB connections between chip and LCD, that may also go with a similar fault somewhere between chip and the 16-way edge connector, possibly in the bonds inside the black "blob".

What exactly do you mean by that?

"The proof of the pudding is in the eating" as the saying goes. More correctly, this matter is both empirical and theoretical. Using a 1k pot wired only as a variable resistor between pin 3 "Vo" and ground will empirically prove to give the most versatile control of the contrast but while this may not be particularly evident, if you comprehend the nature of the contrast ladder (R1 to R5) on the module it will be apparent that this correction also removes an unnecessary current drain.

Thank you everyone, especially Paul and Tom. You guys are a very helpful community and with your help not only have I managed to get the LCD working, I've made it display the temperature in my room using a temperature sensor. Love and respect for you guys

if you have used a lcd.println you might get this two characters after 24.41

Hi,
Great to see it working...
What was the problem?

Tom... :smiley: :+1: :coffee: :australia:

After rewiring the entire board after Paul told me to connect the ground straight to the LCD instead of the Pot, I hurried into connecting the board three pins off :sweat_smile:. But thanks to you, Tom , I was quickly able to notice my stupidity and correct it. The initial problem I suppose was regarding the Potentiometer and its connection to the Ground

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And it does appear that the display is in fact, faulty with lines missing. Can't say whether it would be worth attempting to re-seat the Zebra strips as this might just make matters worse. :woozy_face: