Brightness auto adjusting to ambient light level

[erdem_ua]

Really? Than you just won a SamyGO Brightness sensor
Will post your home later.

So our guy is
#define SamyBacklightReg_B650 0x30220684

could I write that mem region directly via pointer like

Code: Select all

char *val;
val=0x30220684;
*val=0x100;

or is it needed memprotect code etc.Don't diving low level functions each day, rusts everywhere but released wxHexEditor v0.11 yesterday

Next step : calibration with sensor...

[arris69]

Can someone tell me how to call an exeDSP exported function from an external program?
Using dlopen with exeDSP doesn't work.
How could I do that?

as i told you already:
with ptrace:
http://www.linuxjournal.com/article/6100
or you can try (think it uses ptrace also):
elfpatcher: developed by tom_van http://samygo.svn.sourceforge.net/viewv ... lfpatcher/

dlopen is for acces/load library functions and not for executables.

it's a bit other situation when you try to access the functions if exeDSP loaded your library.....

hth
arris

[tom_van]

Good, sbav1

2) 0x30220680: 0x100 for esaving == auto, 0x00 otherwise (from ChelseaPictureShare::m_SetDimmingReg())

Do you have an idea what does auto energy saving really mean? What input does it react on?
Is it based on average picture brightness? And how does it differ from dynamic contrast then?

I'm afraid that 10 steps for backlight is a residuum from some older hardware
and 3 or 4 scales for these 10 steps is a bright idea how to complicate things even more.

[arris69]

...

Hmm.. maybe I have to clarify my question.

ptrace need to be run before the "victim" program.
...

then for what should be a:

Code: Select all

ptrace(PTRACE_ATTACH, pid, 0, 0)

good
http://www.phrack.org/issues.html?issue=59&id=8

arris

ps: but i think it isn't the correct thread for that

[arris69]

...

Code: Select all

char *val;
val=0x30220684;
*val=0x100;

if this code not produce a gpf the whole linux world has a problem

arris

[erdem_ua]

...

Code: Select all

char *val;
val=0x30220684;
*val=0x100;

if this code not produce a gpf the whole linux world has a problem

arris

Yes yes, linux memory mapping different than playing with microcontrollers...
I think I needed to use in/outb with iopl/perm.

[sbav1]

Do you have an idea what does auto energy saving really mean? What input does it react on?
Is it based on average picture brightness?

I think so, backlight gets significantly darker for frames with low mean brightness (for esaving == auto).
Samsung user manual is "a little" sketchy about those features.
For dynamic contrast == on, dimming register (0x30220680) is also set to 0x100; looks like they use similar control method in this dreadful mode .
I think those features are implemented (almost) purely in hardware, they still work when I kill exeDSP (mean brightness/contrast gets computed for each frame, etc.).

Too many unknowns . E.g., in service menu I see two backlight-related settings: Dimm[ing] Type (== EXT in my B650) and PWM MAX (256).
Also there are additional settings in service menu for CE Dimming / contrast dimming. AFAIRC, I turned them off in my TV right after the purchase (to avoid crushed blacks in Movie mode). Yet another control level for fine-grained backlight dimming ?

On hardware level, there are two lines in B650 (between main board and inverter / power supply board) for backlight control: PWM_DIMMING and ANA_DIMMING. But is Samsung using both of them?
Not even to mention local dimming in some LCD sets (supposedly there is FPGA/CPLD chip on main board for that purpose ?).

BTW, does anyone know the exact differences between B650 and B750 mainboards? I was under the impression B750s have 2GB NAND on board; after some googling I'm not so sure.. are the mainboards (virtually) identical?
Light sensor in B750: how is it connected / where is it located (on "Function & IR" board, perhaps ?). I guess CN4002 (4 pin) is JTAG header, so light sensor is probably on CN4001?