Beaglebone 800X600 LCD

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1

I am attempting to add a 8.4" sunlight readable 800X600 LCD to the beaglebone. I have already succeeded doing this with the beagleboard, but the beagle bone is a better fit for may application. I have built the required cape and have a logic analyzer attached to the bone and am able to see the LCD signals. For the beagleboard I had to change resolution by adding a bootarg (omapfb.mode=dvi:800X600-16@60) and I had to modify the timings file ( /sys/devices/platform/omapdss/display0/timings) to match my LCD’s timing.

Is there a correspondingly easy way to use my LCD with the beaglebone, or do I need to delve into kernel code? Has anyone attempted to put together a tutorial on bringing up a custom LCD?

Thanks for the help.

ted

2

I am attempting to add a 8.4" sunlight readable 800X600 LCD to the beaglebone. I have already succeeded doing this with the beagleboard, but the beagle bone is a better fit for may application. I have built the required cape and have a logic analyzer attached to the bone and am able to see the LCD signals. For the beagleboard I had to change resolution by adding a bootarg (omapfb.mode=dvi:800X600-16@60) and I had to modify the timings file ( /sys/devices/platform/omapdss/display0/timings) to match my LCD's timing.

Is there a correspondingly easy way to use my LCD with the beaglebone

No

, or do I need to delve into kernel code?

Yes

Has anyone attempted to put together a tutorial on bringing up a custom LCD?

Have a look at the cape support patches I did for angstrom

3

Hi,

I change the LCD timing by adding timing config info into da8xx_panel known_lcd_panels[], file KERNEL/drivers/videos/da8xx-fb.c,
also change the corresponding name of LCD in KERNEL/arch/arm/mach-omap2/board-am335xevm.c.

Now my LCD panel works, but it seems problem with pixel clock.

  • My LCD is 320x240 and typical pixel clock is 6.5MHz, but if I set this value, the actual pixel clock seems much lower than 6.5MHz, the LCD scan with very low rate. (I don’t have the oscilloscope or freq meter so I cannot measure the actual output frequency).
  • If I set the pixel clock in Kernel to 80MHz, the actual scan rate seems about 15 fps.
  • If I set to > 100MHz then the LCD is always white, maybe it reaches the maximum pixel clock.

And another issue: I can start lxde, but the GUI appear very bad, a lot of noises, color fragment…

I’m stuck here, can anybody guess if I made something wrong?

I will try to use DVI screen to see if there is any difference.