If you read the manual, you will see that these lines are also connected to the HDMI chip. To use it also as an LCD panel, you need to buffer these signals and account for any noise that may be introduced as a result of the loading of these 6ma drive signals my the HDMI chip.
Gerald On Wed, Jul 30, 2014 at 9:16 AM, James S <[email protected]> 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"; > > ti,power-gpio = <&gpio1 2 0x0>; > > ti,allow-non-reduced-blanking-modes; > > }; > > > > -- > 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.
