Sounds like something in the SW has changed. I can't really answer as to what that would be.
Gerald On Wed, Jul 30, 2014 at 9:51 AM, James S <[email protected]> wrote: > Gerald, > > The pins are connected directly to the LVDS chip, a DS90C383BMT. Trace > lengths are short and matched. > But on the same board with the older software, it worked fine - what would > have changed to require the use of a buffer? > > Regards, > James > > > On Wednesday, July 30, 2014 3:43:38 PM UTC+1, Gerald wrote: > >> Still could be the same issue. What buffer are you using to drive the >> signals to the LVDS device? Are the trace lengths match to insure that all >> the setup and hold times are met by having all signals with the same delay? >> >> Gerald >> >> >> >> On Wed, Jul 30, 2014 at 9:40 AM, James S <[email protected]> wrote: >> >>> Hi Gerald, thanks for that reminder. >>> >>> However, there should be no such loading on the White since it doesn't >>> have HDMI on board? The problem also occurs on the White. What else could >>> it be? >>> >>> Regards, >>> James >>> >>> >>> On Wednesday, July 30, 2014 3:16:18 PM UTC+1, James S wrote: >>> >>>> We have a built a custom board with an LCD interface to drive a 1024 x >>>> 768 pixel LVDS panel, 16BPP. It works great on the Beaglebone White with >>>> the old Angstrom 3.2 using the board file configuration. >>>> >>>> We want to use the Beaglebone Black so we built up a system from >>>> http://elinux.org/Beagleboard:BeagleBoneBlack_Debian#2014-07-22 . I >>>> added a dts using the same parameters from the old board file but the >>>> graphics are blurred and corrupted. The card I made boots on the White also >>>> and gives the same results as on the Black. See images below. >>>> >>>> I’ve fiddled with the panel timings but they don’t seem to have any >>>> effect. >>>> >>>> Does anyone have any idea what is wrong and how do I fix it? >>>> >>>> Regards, >>>> >>>> James >>>> >>>> >>>> >>>> This is part of the (good) image from the frame buffer. >>>> >>>> >>>> <https://lh6.googleusercontent.com/-4paVjDS0NME/U9j9QP7ZvyI/AAAAAAAAGjY/Tq2jYoa6r0Y/s1600/screen1.jpg> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> This is a photo of the output on the screen, showing a similar area. >>>> >>>> >>>> <https://lh6.googleusercontent.com/-qR11mE7KhYU/U9j9wMohRZI/AAAAAAAAGjg/_lhBqXIQQyk/s1600/screen2.jpg> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> The following is the panel section of the dts file, based on an LCD4 >>>> dts:- >>>> >>>> >>>> >>>> /* Settings for AUO G121XN01 / mita cape: */ >>>> >>>> panel { >>>> >>>> compatible = "tilcdc,panel"; >>>> >>>> pinctrl-names = "default"; >>>> >>>> pinctrl-0 = <&bone_mita_cape_lcd_pins>; >>>> >>>> panel-info { >>>> >>>> ac-bias = <255>; >>>> >>>> ac-bias-intrpt = <0>; >>>> >>>> dma-burst-sz = <16>; >>>> >>>> bpp = <16>; >>>> >>>> fdd = <0x80>; >>>> >>>> tft-alt-mode = <0>; >>>> >>>> stn-565-mode = <0>; >>>> >>>> mono-8bit-mode = <0>; >>>> >>>> sync-edge = <0>; >>>> >>>> sync-ctrl = <1>; >>>> >>>> raster-order = <0>; >>>> >>>> fifo-th = <0>; >>>> >>>> invert-pxl-clk = <0>; >>>> >>>> }; >>>> >>>> display-timings { >>>> >>>> native-mode = <&timing0>; >>>> >>>> timing0: 1024x768 { >>>> >>>> hactive = <1024>; >>>> >>>> vactive = <768>; >>>> >>>> hback-porch = <80>; >>>> >>>> hfront-porch = <48>; >>>> >>>> hsync-len = <32>; >>>> >>>> vback-porch = <15>; >>>> >>>> vfront-porch = <3>; >>>> >>>> vsync-len = <4>; >>>> >>>> clock-frequency = <56000000>; >>>> >>>> hsync-active = <0>; >>>> >>>> vsync-active = <0>; >>>> >>>> }; >>>> >>>> }; >>>> >>>> }; >>>> >>>> >>>> >>>> fb { >>>> >>>> compatible = "ti,am33xx-tilcdc"; >>>> >>>> reg = <0x4830e000 0x1000>; >>>> >>>> interrupt-parent = <&intc>; >>>> >>>> interrupts = <36>; >>>> >>>> ti,hwmods = "lcdc"; >>>> >>>> &nbs >>>> ... >>> >>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "BeagleBoard" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
