image not displayed on tft screen

[arnold]

Posted on April 12, 2013 at 19:17

Hello,

I have developt a project with Coocox. It works almoost, there is text displayed on my tft but the image included in the main file is not displayed. What did i do wrong, could someone look into it. thanks

[Tesla DeLorean]

Posted on April 12, 2013 at 19:57

Is this for some specific board? Might be important to communicate this.

Perhaps the issue is in the SSD1289 library code? Either the commands, or data transfer, may be flawed. Speak to the people that wrote the library, or designed/provided the hardware.

[arnold]

Posted on April 12, 2013 at 20:24

Yes this is for the stm32f4 discovery.

I think the code is correct because the text is displayed, so the screen is initialized correct. and output to the screen goes also good. so i have to look into the code

[Tesla DeLorean]

Posted on April 12, 2013 at 20:35

Does it paint the text bitmaps locally, and copy them, like the BMP? The transfer size for text element, I'd imagine, is much smaller.

[frankmeyer9]

Posted on April 13, 2013 at 15:54

I guess this could be a bug in your display driver code.

I dealt with some of this displays recently, and realized they use windows rather frequently. Meaning, they restrict the accessible area of the TFT to just the size required for the operation, and dump the data in via writes to consecutive addresses. For text, it uses a 5x7 window (for a 5x7 font). Before drawing a picture, you need to restore the window size to the whole screen. As said, just a guess...

[jj2]

Posted on April 13, 2013 at 21:17

Believe advice given by both Clive and fm is sound - here's how you can test/verify:

a) using simple program such as PC ''Paint'' - create a very small graphic (i.e. 3 vertical bars) which fits w/in a 5x7 pixel area.  (5 pixel width)  You can create and then save this in either mono or color - I'd start w/mono for simplicity.  Unknown then is whether your ''graphic image file to TFT'' converter/program can correctly ''massage out'' this file data.  You must better identify - and then comply - with any/all of your system's ''converter/program's'' rules & protocols.  Once you've succeeded in displaying this small 5x7 pixel image - gradually expand it - noting if and when the process ''breaks down.''   Armed with this knowledge - you/others will be far better equipped to assist...