A13-LCD43TS calibration problems

[mb]

Hi!

I just got my A13-OLinuXino-WIFI board and the 4.3" touch screen LCD to boot using the pre-loaded (NAND) Android image modified according to the wiki (https://docs.google.com/file/d/0B-bAEPML8fwlcHFOcUxtQ1N5RDQ/edit?pli=1). I'm having some trouble with the touch screen though -- touch input is way off especially in the x axis (see picture). I managed to launch the built-in screen calibration app by connecting a mouse, however it doesn't seem to do any good since it never finishes (crosses moving around the screen forever). If I enable coordinate plotting it shows x = ~360 for the leftmost part of the screen and x = ~780 for the rightmost.

Anyone got a clue about how to get this right?

Picture: http://imgur.com/tSnfYXU

/Martin

[olimex]

this is issue with no solution for the moment, Dimitar told me the touchscreen is hardcoded for 7" in Allwinner android image so using 4.3" LCD for the moment is OK for the display resolution, but touchscreen can't be calibrated properly yet on Android
hopefully someone with more knowledge can fix this

[mb]

OK. I think I have actually managed to get the 4.3" touch screen working in Android now by changing the hard coded screen size in the kernel touch driver and by inverting the X axis. Had to hack my way through the calibration app as well but it seems to work well enough now. I'll try to post my changes somewhere soon after I have cleaned it up a bit.

A related question -- are the LCD timings/settings in the .fex config file on the wiki really 100% correct? Every time the screen is powered on there is some error checking triggered from the driver (in disp_lcd.c):

Code Select Expand


...
[ 5774.440000] [DISP] *** Lcd in danger...
[ 5774.440000] [DISP] *** Lcd in danger...
[ 5774.450000] [DISP] *****************************************************************
[ 5774.450000] [DISP] ***
[ 5774.460000] [DISP] *** LCD Panel Parameter Check
[ 5774.460000] [DISP] ***
[ 5774.460000] [DISP] ***             by dulianping
[ 5774.470000] [DISP] ***
[ 5774.470000] [DISP] *****************************************************************
[ 5774.480000] [DISP] ***
[ 5774.480000] [DISP] *** Interface:
[ 5774.480000] [DISP] *** Parallel HV Panel
[ 5774.490000] [DISP] *** Lcd Frm to RGB666
[ 5774.490000] [DISP] ***
[ 5774.500000] [DISP] *** Timing:
[ 5774.500000] [DISP] *** lcd_x:      480
[ 5774.500000] [DISP] *** lcd_y:      272
[ 5774.510000] [DISP] *** lcd_ht:     525
[ 5774.510000] [DISP] *** lcd_hbp:    2
[ 5774.510000] [DISP] *** lcd_vt:     572
[ 5774.520000] [DISP] *** lcd_vbp:    2
[ 5774.520000] [DISP] *** lcd_hspw:   41
[ 5774.520000] [DISP] *** lcd_vspw:   10
[ 5774.530000] [DISP] *** lcd_frame_frq:  59Hz
[ 5774.530000] [DISP] ***
[ 5774.530000] [DISP] *** Err01: Violate "lcd_hbp > lcd_hspw"
[ 5774.540000] [DISP] *** Err02: Violate "lcd_vbp > lcd_vspw"
[ 5774.550000] [DISP] ***
[ 5776.550000] [DISP] *** Try new parameters,you can make it pass!
[ 5776.550000] [DISP] *** LCD Panel Parameter Check End
[ 5776.560000] [DISP] *****************************************************************
[ 5776.560000] display late resume done: backlight_late_resume
[ 5776.570000] enter laterresume: sun4i_keyboard_resume.


The data sheet doesn't say much...

Thanks!

/Martin

[mb]

I just disabled the LCD parameter checks and everything seems fine so far. Hopefully it won't break.

If anyone else runs into the same problems with the 4.3" screen I've made my changes available as patches here:

https://github.com/mbrrg/olinuxino-a13/tree/master/android/lcd

[mj_2000]

Hi Martin,

I have same problem as you. Do you have a pathed img file?
I don't have linux machine, so I can't compile kernel my self.