Tuesday, 6th of January 2009
Tuesday, 6th of January 2009
"sony acx705akm-7" — 1 post
I bought two of these LCDs and the associated connectors from Electronics Goldmine. You can get one here.
For twenty bucks, I couldn't pass it up. Would have preferred to get something with a touchscreen interface, but this is a good size. The datasheet is here.

I followed much of the info on the wiki. Here is the pinouts and connection for my connex 400 (R687):

03 VCC
04
VCC
05
GND
06
GND
07
R0 (Red data input LSB)_________________ _ L_DD13 Pin 08/GPIO(71)
08 R1 (Red data input)_____________________ _ L_DD14 Pin 55/GPIO(72)
09 R2 (Red data input MSB)_________________ _ L_DD15 Pin 56/GPIO(73)
10 G0 (Green data input LSB)_______________ _ L_DD08 Pin 06/GPIO(66)
11 G1 (Green data input)_________________ _ _ L_DD09 Pin 02/GPIO(67)
12 G2 (Green data input MSB)___________ __ __ L_DD10 Pin 51/GPIO(68)
13 B0 (Blue data input LSB)___________ ____ _ L_DD02 Pin 13/GPIO(60)
14 B1 (Blue data input)______________________ L_DD03 Pin 04/GPIO(61)
15 B2 (Blue data input MSB)__________________ L_DD04 Pin 47/GPIO(62)
16 HSYNC (Horizontal Line Synchronization)-> LCLK Pin 16/GPIO(75)
17
VSYNC (Vertical Line Synchronization)--->FCLK Pin 41/GPIO(74)
18 S/D (Shut down)-------------------------> #STBY GP_81 Pin 21/GPIO(81) (NSSP_CLK)
19
MCK (Master Clock) --------------------->L_PCLK Pin 57/GPIO(76)
20
VCC______________________________________VDD_2
21
LED VDD (Backlight VDD)___________________________
22
LED GND (Backlight GND)__________________________

The connector has 0.5mm pins which i wasn't up for soldering wire-wrap up to directly, although other have. Instead I bought a little board from Schmartboard. It is the #202-0007-01, you can see the whole board here. I trimmed it down to what you see below:





































I connected up the board and connector according to the above chart and epoxied over the connector under the board.


I followed the wiki to setup the kernel and bootargs. Some of the options have changed in the kernel menuconfig. I have:
Device Drivers->Character devices->Virtual Terminal = Enabled
Device Drivers->Graphics support->Support for frame buffer devices = Enabled
Device Drivers->Graphics support->Enable Video Mode Handling Helpers = Enabled
Device Drivers->Graphics support->PXA LCD framebuffer support = Enabled
Device Drivers->Graphics support->PXA LCD command line parameters = Enabled
Device Drivers->Graphics support->Console display driver support->VGA text console = Disable
Device Drivers->Graphics support->Framebuffer Console support = Enabled

fbcon got compiled with the above. I chose Chris Diamond's ALPS driver. I first tried the "none of the above" options but then the bootargs didn't do anything. Chris said that it needs some settings, then you override them in bootargs. I haven't had time to look into setting up a menuconfig option for this screen yet.

I'm using the following bootargs:
GUM> setenv bootargs console = tty0 console=ttyS0,115200n8 root=1f01 rootfstype=jffs2 reboot=cold,hard 
video=pxafb:mode:240x160-16,active,hsynclen:7,right:16,left:6,upper:19,lower:19,vsynclen:2,hsync:1,vsync:1,pixclockpol:0,
pixclock:216363
GUM> saveenv
I connected it up to a bench powersupply and fired it up. I had a small solder bridge on two of the pins which caused some problems, but once I cleared that everything was fine. Above you can see a .pbm image blitted to the board.


to start the screen:
pxaregs GPSR2_81 1

Here are a couple of the escape commands for fbcon:
echo "Hello World!" > /dev/tty0 //text output
echo -ne '\033[0;0H' > /dev/tty0 //move cursor to 0,0
echo -ne '\033[?25l' > /dev/tty0 //turn off the cursor
echo -ne '\033[?25h' > /dev/tty0 //turn on the cursor

I powered the backlight (2 LEDs) and around 6-7v it seems brightest. This isn't a very bright LCD. White's are grey. As long as you are happy with that, then this is a pretty good, cheap LCD with a small form factor.