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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 October 28, 2013 at 19:09

I'd think the SDRAM on the STM32F429I-DISCO would be more than adequate, and 1/10th the price.

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megahercas6
Senior
Posted on October 28, 2013 at 21:31

Since cost is no issue, if that gives 10% more speed  or even lower, i use it. I just don't know much about memory, and bandwidth.

Posted on October 28, 2013 at 22:25

You may be want to think about that, and the requirements of the display.

The SDRAM on the DISCO has 4x the capacity (8MB vs 2MB), is 10x cheaper ($2 vs $20). The part you spec'd is also a BGA which also tends to be more expensive to use, increases PCB layers/issues/cost, fab and rework. The DISCO board is likely 4-layer, the EVAL board probably 8-layer.

SDRAM is better suited to rastering applications like screens, or linear DMA access, exactly how beneficial will depend on ST's implementation, which I haven't thoroughly analyzed, but seems to have caching/acceleration which improve performance of the rather woeful external busing. M3/M4 designs are best suited to closely coupled memories, and reason to select the F4 over something better suited to large panels?
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megahercas6
Senior
Posted on October 28, 2013 at 22:44

I really don't want to use something that has more performance. Even STM32F429 is to much for the task, but i am participating in concurs, and i need to impress peoples, who will vote for my project.

It will be used in DIY reflow oven, STM32F429 coupled with HTC Desire touchscreen (http://youtu.be/eUg27cu6eFY)as well as AMOLED screen will be used for user interface, and PSoC will run PID loop for temperature control. I have large budget for this project, so i want to make it as fast as possible while using familiar parts. I guess that will be first oven capable of cooking and calculating Mandelbrot series at the same time :)

I would use similar SRAM, just in TSSOP package.

Posted on October 29, 2013 at 00:00

Remember, something that doesn't work, doesn't impress anyone.

Consider if you can proof-of-concept the screen interface by modding an STM32F429I-DISCO board. Remove the screen, wire up the HTC screen. I see they are pretty cheap, but couldn't find an interface document quickly.

[DEAD LINK /public/STe2ecommunities/mcu/Lists/STM32Discovery/Flat.aspx?RootFolder=/public/STe2ecommunities/mcu/Lists/STM32Discovery/stm32f429%20Disco%20direct%20to%20VGA%20Monitor&FolderCTID=0x01200200770978C69A1141439FE559EB459D75800084C20D8867EAD444A5987D47BE638E0F&TopicsView=https://my.st.com/public/STe2ecommunities/mcu/Lists/STM32Discovery/AllItems.aspx&currentviews=203]https://my.st.com/public/STe2ecommunities/mcu/Lists/STM32Discovery/Flat.aspx?RootFolder=%2fpublic%2fSTe2ecommunities%2fmcu%2fLists%2fSTM32Discovery%2fstm32f429%20Disco%20direct%20to%20VGA%20Monitor&FolderCTID=0x01200200770978C69A1141439FE559EB459D75800084C20D8867EAD444A5987D47BE638E0F&TopicsView=https%3A%2F%2Fmy%2Est%2Ecom%2Fpublic%2FSTe2ecommunities%2Fmcu%2FLists%2FSTM32Discovery%2FAllItems%2Easpx¤tviews=203

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megahercas6
Senior
Posted on October 29, 2013 at 06:42

Are you talking about datasheet ?

I gone a long way trying to reverse engineer this screen, and i even get datasheet not only for panel, but for OLED controller embedded on glass. And molex has right connector, so i can make pcb for it.

If some one are interested connecting amoled, let me know, i will share design files

megahercas6
Senior
Posted on October 29, 2013 at 06:43

Posted on October 29, 2013 at 15:29

A data sheet would be fantastic, I was fishing more for a pin configuration chart, ideally one with standard signal equivalents.

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megahercas6
Senior
Posted on October 29, 2013 at 17:39

i have datasheet for SLCD and AMOLED ,

finishing pcb adapter for amoled, maybe you can help to set up LCD controller ? (files attached to this post)

Hm, that is fun, i made pcb, it looks like working (inverters and so on). Now i don't know what exacly to write via spi and how :(

in 2-3 weeks i will get adapter, so i can hook SPI decoder while phone is still working with screen, and that way extract all init data.

I know all timings by probing lcd connector , so maybe at least this part will be easier. But for now, i don't know what to do, it a bit complicated for me, and i have way to much work in other areas so not much free time for this

________________

Attachments :

ACX425AKM_Ver0.4_20100624_201306185709.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0ie&d=%2Fa%2F0X0000000bcw%2FiDcmkKm99_48kmO2Y3L9RsnE5f.lHk1sxpyK_DyKVRs&asPdf=false

AMS369FG03-002_Rev2.0_20090603_201210156706.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0cX&d=%2Fa%2F0X0000000bcv%2FxJ7Su9z2Xv0qA_OAV.xQBp2QDJw8qANPqu7Hc393AM8&asPdf=false

controller.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0Wj&d=%2Fa%2F0X0000000bcu%2F5I5zqvSjLc75rujYUohJSuHj440eZXFoWlVtTBm1Ti4&asPdf=false

TEK00005.PNG : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0iK&d=%2Fa%2F0X0000000bcs%2FxQkqnUF.G.4T4n0nizJYGDhDaamp4AN.dZKykvLfSjk&asPdf=false