Hello there!
I am trying to get a graphic LCD up and running using my diecimilla. I hooked up all the wires and uploaded the example. So far so good.
The issue I had was temperature of the Arduino itself. The chip and the voltage regulator got very hot, I nearly burnt my fingers touching them.
Is this a common problem? Is my LCD taking too much amps? Do I need another power source?
Any help is appreciated!
-andreas
Hi Andreas, it sounds like something is drawing too much current. Almost all the current used by the typical LCD panel is consumed by the backlight, and for all the panels I have seen that use an LED for backlight, this should be less than around 60ma or so. That shouldn't be enough to overheat the regulator.
Did you check the datasheet for your panel to see if you need to use a dropping resistor for the backlight and do you have the right value connected?
Thanks for the fast reply!
This is the Datasheet to it..
http://www.artronic.pl/o_produkcie.php?id=684?
What kinda disturbs me is the line:
Operating Voltage for LCD: 13V
So I need a seperate powersupply to fire up the LCD. I've ordered a batch of boarduinos. Maybe I am going to use a 15V powersupply and I will try to set down the voltage to 5V for the "logic" part of the circuit.
What do you think about?
Thanks...
-andreas
The 13 volts is generated internally, you only need to provide 5 volts. That backlight uses 150ma and that may be what is causing yr regulator to get warm. Perhaps you can fit some kind of heat sink to the regulator, or use an external 5v supply. But first check that the backlight is not drawing more than 150ma, its not clear if a series resistor is already in place (although I would guess it is)
Hmm I've tried wiring up the LCD without the backlight. But I still got the issue of the high temperature on the Atmel.
Strange thing.. Any suggestions? Should I just leave it and get another display?
Andreas, I presume that you have tried it without the LCD connected and its ok. If so there is probably a short circuit somewhere on the LCD. Have you tried to contact your supplier?
hi.. i hav ineterfaced 128x64 pixel graphics lcd to atmega32. the lcd on start up is supposed to show an image and then show the menu.. when it is powered on, the starting portion of right chip (pixels 64 to mayb 75) do not show the respective data..Further in the menu at times the starting portion of the second chip show the same results.. My hardware is proper..PORTB for data .. and control lines on some pins of PORTC and PORTD..can any one please suggest wat could be the problem and a possible solution for the same???
Thanks..
Ajfreak,
The problem may be that your lcd panel is responding too slowly. Pixels from 64 are on a different chip from pixels 0-63 and some panels respond more slowly than others. I have been working on a number of methods for coping with slow chips and none of the things I have tried work on every panel. Unfortunately, a number of things have got in the way of me finding an generic solution to this, perhaps I can find some time over the xmas break to look at this again.
In the mean time, if you post some pictures of the symptoms, perhaps I can suggest some things for you to try.
Thanks for the reply sir..
The behaviour is same for graphics as well as text..
I am writing a string say "Hello world"..now i display this string on start up ie screen 1, den based on menu, i display it on all my screens... i hav nearly 10 such screen whr on topmost line i display this msg...now string is printed wrongly in say 2 out of the 10-screens.. what could be the problm ...i need help urgently........
It will be easier to me to help if I can see what the display looks like. Can you take a picture that shows the problem and post it on one of the file sharing sites like flickr
i gues i will not b able to upload any photos sir...isnt the problem clear..m sry if i am unable to xplain it...the problem still continues..in some screen the data is perfectly printed while in others it prints d data n then erases only part of it...m using the ks0108 routines and have used it succssfully with at89c51...please suggest me smthng,,
Also the upper 3 pins (PB.6,7,8) are being used for ISP using SPI interface...When i have to download the code i need to disconnect the lcd hardware since it is also using port B. wen the programmer is still connected and i turn ON the system, the display is still distorted but not bad..When i remove the programmer frc, and turn ON the system the screen display is poor...Could the SPI interface b bothering my LCD... ALso the voltage level on the pins drops wen the programmer is connected...
Lets see if we can clarify what is happening:
If you are asking if its ok to have an SPI device connected to some of the LCD pins, the answer no, the lcd pins should not be connected to anything else (at least until you have the lcd working correctly)
Not sure if you are saying your lcd is ok when running different software on a different controller. If so, can you post (or pm) me the link to the software that works ok.
It is difficult for me to visualize what you are seeing. Is there some way you can get pictures or a video that you can post on one of the image sharing sites?
The In System PRogrammer is sharing 3-pins (MISO,MOSI,SCK ) witj the 3 data bits of PortB (Port B.6,7,8). Before programming if the LCD connector is connected and i try to programm the chip, it gives me an error.. I have to remove the lcd connector and then download the program. After programming,if i connect the LCD connector(with the ISP still connected), the output is gud but still distorted..the vtg levels at these pins being (1.7,0.3,0.3 V repectively ) and /RST = 3.4V
If i remove the ISP FRC connector, the vtg level are (1.5,1.5,1.5 V) and /RST = 5V and the output is completely distorted.
i hav tried usign a pull down resistor at PORT B , but still no use....
Are you saying it works better when you have your programmer connected? strange
I have not seen the need for pull-up or pull-down resistors on any of the many panels I have tried.
The data pins are switched between input and output on almost every lcd function and it could be in input mode when idle. Determining the voltage levels on the pins requires an oscilloscope.
I am still curious to understand the meaning of your earlier comment: “have used it successfully with at89c51” If you have source code that works with you panel, I would be interested to see it.
And it difficult to visualize what you are seeing when your screen is 'distorted' vs 'completely distorted'. Some pictures may help to diagnose the problem.
yes..it does perform better wit isp connected...and the pull down resistors wer of no use either,,
ajfreak, It would be great if through the magic of the internet we could read your mind and see what you see, know what you know. Unfortunately, that service is not yet available 
In my previous two posts I asked if you could post some pictures or videos to show what your screen is displaying. I have no idea what you mean by distorted' and 'completely distorted', or how this relates to the statement that “in some screen the data is perfectly printed while in others it prints d data n then erases only part of it”.
I also asked if you would clarify what you mean when you said you “have used it successfully with at89c51”
I will be happy to try to help if you can provide more information and some pictures or videos of your symptoms.
hi sir..
can i hav ur mail id whr i can send u d image of d current lcd display...
also it seems to be "EMI pick up" problem...if i press the cs1 and cs2 pins on LCD , d display becomes perfect..if i leave it , it returns to the same state..kindly giv me ur id whr i can upload the image..
You can post images on any of the public image sharing sites such as flickr http://www.flickr.com/
Create an account (its free) and follow the instructions to upload images. You can use the 'insert image' (third icon from left in the reply toolbar) facility here to past a link to the external image url.
if u can t view dis img plz letme knw..
If are able to view it, the portion in blue at the start of chip 2 is what i was talking abt wen i said "distorted". Please suggest me something for this soon...