jhd 162a 16x2 LCD problems

i got this lcd today and tried wiring it up to my test arduino board and loaded a sketch from the arduino17 ide, licuidcrystal. all i get is black boxes. i tried different sketches and still nothing, al is wired up right apart from the contrast where i had to connect pin 3 (Vee) to gnd via a resisitor.

the pic in this thread shows wat i get on screen: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1253042156/0#0

buti cant read german so i have no idea wats going on there XD

my screen is blue with white txt.

is it obviose im doing summin wrong or is there summin up somewhere?

Hey, I'm just curious.. have you tried any other hardware setups for the VEE? I tried to connect mine with just a resistor.. with no good. Once I hooked up a Trimmer pot, worked fine. I measured the resistance of the pot.. and tried a resistor.. no good, I'm fairly positive it needs at least a voltage divider.

Another thing to keep in mind, in 0017, you now need to include lcd.begin(16, 2); // in your setup to get the lcd to initialize correctly.

If you've tried both of those, I would break down the setup, unplug everything, and start over.. tends to be much easier to find my errors that way :)

Best of luck, and let us know what does it for you, so we can have an English reference as well. :D

thanks i’ll give it a try tomorrow :slight_smile:

so i could make a voltage divider with 2 resistors and connect the Vee between?

Will let u know how i get on…


the pic in this thread shows wat i get on screen:

This is what you get when the power is connected properly but the LCD controller is not initialized properly.

The fact that the top line has dark boxes and the bottom line is blank means that the power is connected properly to pins 1 and 2.

The fact that the dark boxes are [u]very[/u] dark means that your contrast is not exactly right . You have grounded the contrast pin which is the reason for this symptom but you should still be able to get a usable display so wait and fix this later.

The LCD controller will not be initialized if any of the following are not correct: 1 - The code has to be written correctly. The version 0017 liquidCrystal initialization code does not follow the datasheet perfectly but it is the best there is. You can be pretty certain that it is not the problem.

2 - The code has to be implemented properly and CaptainObvious has pointed out the part that many people miss.

3 - The connections between your Arduino and the LCD module have to match what liquidCrystal is expecting. This is most likely your problem and I agree with CaptainObvious - pull out the data and control lines and start over.

Maybe the bong has something to do with your problem. It seems to have affected your spelling as well, although it's better than my Norwegian. (sorry - I couldn't resist)


Well the code looks ok, its all wired up as the sketch said. maybe its my board or something, the sketch was running because i had it send out the message via serial to the monitor so i could make sure.

my board is a custom one running the lillypad bootloader, its getting a little old and may have lost some of the pins functions, if thats the case then i will have to try another board to be sure.

will get back to u later.

and i dont smoke so no bongs XD


The screen works fine connected to the printer port and running LCDSmartie so its defiantly not that ;)

will dig out my dual core board and test it out on that wen i get a chance..

I will be retrying this when i get my RBBB and second LCD thru post ;)

the 1st lcd is happily displaying junk from the pc :P

This problem may occur if R/W (PIN 5) is not connected to GND.

Posted by: junkFellow Posted on: 01.10.2009 at 05:36:55
This problem may occur if R/W (PIN 5) is not connected to GND.

Bingo! that did it :slight_smile: thnx :3

I'm glad yours works! Mine wont, I've re hooked up soldered everything! Just sits blinking ! :( should of just bought one from here not on ebay!

I've purchased all of my LCDs on eBay.. all of them work great too. It took me a few times to get used to how they're connected.. so I'm going to guess it's user error Kryptek :)

I have an el cheapo Ebay LCD working fine here too.

This is where I started, a pretty easy place to start with a prewritten sketch (albeit advertising). The same wiring works with the far superior standard Library.