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Topic: Womart TFT LCD Shield + Touch Panel Display (Read 11 times) previous topic - next topic

alfelipe

#5
Mar 09, 2013, 11:21 pm Last Edit: Mar 09, 2013, 11:44 pm by alfelipe Reason: 1
HI. Just I solved my problem and just access the forum to communicate it. If the TFT device is in black absolute and there is not even a gray image background, you should adjust the potentiometer in the adapter shield. I recommend you check this: just in the pin opposite to the pin marked as "JP2" on the TFT shield, if there is no a voltage slightly above 2.5 volts no light whatsoever, you will get a black screen. You must adjust the potentiometer even without running softare, until the TFT reach a light gray background. Turns clockwise increase the voltage. The reference is about 2.6 volts in the pin marked in the photograpy. Try it and see how it works. The potentiometer is like a brightness control but with a very critical threshold. I was tracing signals with oscilloscope this afternoon looking for the failure. I bought a second pair of TFT and ADAPTER shields in Womarts and for this reason I knows the problem was located in the adapter shield.  Very simple? I must be an idiot for not having tried to adjust the potentiometer first before buying another pair of shields. :-)
More simple: if you get a blank (no gray) screen, turn clockwise the potentiometer, without running software, until you reach a light gray background. ;-)
Sorry, but I don'n know how upload the photo in this post. You can see it in http://www.sepca-sctfe.org/downloads/arduino.jpg

fabz56

Hi,
Thanks for your reply. In fact, I had a totally black screen so I asked to Womarts and they told me to adjust the potentiometer 15 rounds counterclockwise. I already tried it and I checked with my multimeter but there was nothing on the pin 19. I checked on the arduino and there was 0 volt on the pin 3.3 volts. So I have a problem with the arduino :( I explained the problem to Womarts and they send me another one :p
I borrowed another mega to a friend and all works fine with the UTFT and Utouch librairies...

mclarkva

I struggled with a SainSmart 3.2 LCD and adapter card and then realized I had the libraries and examples in the wrong folders as well as the wrong model number. Using Sain Smart download (link below) or Henning's code I had the same problems - because I was making the same mistakes. Here was my solution:

So, the new auto import puts libraries where they need to be. Using IDE Arduino 1.5.2 you can import the zip file ( Sketch|> Import Library|> Add Library...) the  32lcd.zip file from Sain Smart document needs to be renamed because it starts with a number  so rename the zip to something like SS32lcd.zip. The automatic import of arduino 1.5.2 IDE will put the UTFT library files in the right place. You will still need to copy the example folder over to the example folder in the ....\arduino-1.5.2 IDE installed folder for them to show up in the File|>Examples|>  menu.  You can save your changes into your sketchbook and your customization will be preserved there.

http://www.sainsmart.com/sainsmart-3-2-tft-lcd-display-touch-panel-pcb-adapter-sd-slot-for-arduino-2560.html [font=Verdana]download link 2[/font]

then change the line:

UTFT myGLCD(ITDB24E_16,38,39,40,41);   // Remember to change the model parameter to suit your display module!
to the SSD1289 model for the Sain Smart unit

UTFT myGLCD(SSD1289,38,39,40,41);   // Remember to change the model parameter to suit your display module!
  resave this modified file to your sketchbook using File|>SaveAs

now the example UTFT_Demo_320x240.ino works!


Notes:

The IDE must be closed and restarted to see the new libraries and the Example files

Once you see how the auto library import install sets up the folders using the zip file you could use  Henning's rar files extracted and moved to the same places - I haven't figured how to get the arduino import to accept a RAR file

Once you get all the linked libraries installed in the right folders you can open sketches from other locations BUT if the linked libraries have changes the IDE will still see the old versions you put in using the import feature.

Libraries in the wrong place will throw less than helpful compiler errors like : 'UTFT' does not name a type

Libraries with the same names in different folders could lead to using a different library than the one you have just downloaded or are expecting or the one you just modified but is in a different folder- be careful to watch directory structure and use new names

"Arduino Cookbook" by O'Reilly has some simple explanation of Libraries and directory structure CH 16 starting page 561



twinsfly

me too,I've just received mine from womarts and I have the same problem   

alfelipe

If your problem is a black display, the solution is in reply #5. Many lucky.
Álvaro.

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