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STM32F429 and AMOLED screen

megahercas6
Senior
Posted on October 26, 2013 at 23:51

Hello,

for my project i need to connect HTC Desire screen to STM32F429. it has 800x480x16b resolution, RGB565 standart.

To get best peformance, should i use original SDRAM (like in SDTM32F429i_DISCO board), or it would be faster to use SRAM like IS61WV102416BLL-10TLI?

And if yes, how much different programming would be, to be able run original STM32F429i-disco programs (Segger UI)? (i only should do config, and rest is fine ?, address looks like will be the same for FMC controller )

Also will i fit into this memory my design ? 800x480 use 384k*16, so with 1M*16 i should be fine ?

Many thanks for any help on this question
23 REPLIES 23
Posted on November 01, 2013 at 22:10

My experience with the LTDC/LCD stuff is pretty limited.

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megahercas6
Senior
Posted on November 01, 2013 at 22:49

Screen now is +- working. And contrast is superb, 1:10k. LCD can't do that. and viewing angle is >80 in all directions

(Hrr, fun does not end here, i have no blue color, have no idea why. I tested AMOLED and it is working with phone as it should. Ideas ? )

http://www.youtube.com/watch?v=-HWi4mpZ_PE

if i want speed i can overclock, nearly double original speed, and if i want even more speed i have ADSP-21489 for it. And even if that would be slow, i always can take arm cortext A9 running 1.2GHz ( TI Sitara )

My goal is to get it working, so i can use it for project as it is, or use integrated controller like S1D13517.

I give up. I extracted init values while probing phone, i set LTDC controller so it generates same timings as my phone. and yet, i have problems upon problems. My biggest that i don't have one of three colors, now i don't have RED color,even if i connect all RGB565 line to VCC ( i should get white, but no, i get cyan).

Even when timings are the same, i have small line for x and y coordinates. Now only thing that's left is AMOLED voltage that is different. Phone use 2.8V for internal circuitry, but i use  3.3 ( max is 3.6V, so i should be ok ) VSS is exactly the same since i have DC/DC converter for it. and power-up is controlled by AMOLED controller, and it's working)

I don't know what can i do more. I only need to get it working, speed is not a problem for testing

Posted on November 02, 2013 at 19:18

Good work. May be the BLUE requires a different/additional supply? They have different current/brightness issues compare to RED/GREEN.

The Discovery board normally run at 3V, though I suspect you could change the regulator.
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megahercas6
Senior
Posted on November 02, 2013 at 19:26

How about that ?  - > 

http://youtu.be/y3P8ilMc1E4

ok, so now we can try  to make it faster. Idea is to use fpga ( just bear with me for a second ) to double PCLK, and adjust VSYNC,HSYNC to match my new setup. if i double PCLK i will get 240x400 resolution,  so at that point i should get very fast updates.

http://s9.postimg.org/mlalgcxdq/IMGP2451_Copy.jpg

If i understand correctly, adding

http://www.epson.jp/device/semicon_e/product/lcd_controllers/pdf/s1d13517/s1d13517_spec_rev_1.2.pdf

( high performance LCD controller ) will not add any speed improvement ?