I wanted to connect a LVDS LCD Panel directly to my cubieboard - not using an HDMI cable.

Hardware

  • cubieboard 2
  • old toshiba 12” LCD panel (800x600)

useful links

  • http://linux-sunxi.org/Display
  • http://linux-sunxi.org/Cubieboard/LVDS
  • https://linux-sunxi.org/Fex_Guide#disp_init_configuration
  • http://tinyvga.com/vga-timing/800x600@60Hz

How i did it

First i changed the fex configuration

  • mount the boot partition: mount /dev/nanda /mnt/

  • the binary device configuration must be converted to human readable form bin2fex /mnt/script.bin /root/1.fex

  • edit fex file (see content below)

Content to add to fex file:

[disp_init]
disp_init_enable = 1
disp_mode = 0
screen0_output_type = 1
screen0_output_mode = 5

[lcd0_para]
lcd_used = 1
lcd_x = 800
lcd_y = 600
lcd_dclk_freq = 51
lcd_pwm_not_used = 0
lcd_pwm_ch = 0
lcd_pwm_freq = 10000
lcd_pwm_pol = 1
lcd_max_bright = 240
lcd_min_bright = 64
lcd_if = 3
lcd_hbp = 158
lcd_ht = 1056
lcd_vbp = 23
lcd_vt = 1256
lcd_vspw = 3
lcd_hspw = 20
lcd_hv_if = 0
lcd_hv_smode = 0
lcd_hv_s888_if = 0
lcd_hv_syuv_if = 0
lcd_lvds_ch = 0
lcd_lvds_mode = 0
lcd_lvds_bitwidth = 1
lcd_lvds_io_cross = 0
lcd_cpu_if = 0
lcd_frm = 1
lcd_io_cfg0 = 0
lcd_gamma_correction_en = 0
lcd_gamma_tbl_0 = 0x0
lcd_gamma_tbl_1 = 0x10101
lcd_gamma_tbl_255 = 0xffffff
lcd_bl_en_used = 0
lcd_bl_en = port:PH07<1><0><default><1>
lcd_power_used = 0
lcd_power = port:PH08<1><0><default><1>
lcd_pwm_used = 0

  • convert the fex file back to binary fex2bin /root/1.fex /mnt/script.bin

  • unmount boot partition umount /mnt/

  • change uEnv.txt as follows, to make the cubieboard use the other output.

Content of uEnv.txt

console=tty0
extraargs=console=ttyS0,115200 disp.screen0_output_mode=800x600  rootwait panic$
nand_root=/dev/nandb
  • wire the panel

Panel Connections

The following table shows the connection of panel signals to the cubieboard. Additionally, there are connections for power supply of the panel and the panels backlight.

cubietruck2 pin name lcd pin cable color
09 Ground GND black
07 PD6 (LCDD6/LVDS0PC) 06 (RXC+) brown
10 PD7 (LCDD7/LVDS0NC) 07 (RXC-) brown-white
05 PD4 (LCDD4/LNVS0P2) 09 (RX2+) blue
08 PD5 (LCDD5/LVDS0N2) 10 (RX2-) blue-white
03 PD2 (LCDD2/LVDS0P1) 12 (RX1+) orange
06 PD3 (LCDD3/LVDS0N1) 13 (RX1-) orange-white
02 Ground GND black-white
01 PD0 (LCDD0/LVDSP0) 15 (RX0+) green
04 PD1 (LCDD1/LVDS0N0) 16 (RX0-) green-white

Yess !

The result on my bench. it works