Hi,
I have built a DVI to LVDS bridge using the TFP401A and SN75LVDS83B as part of a university project. I am using it to connect a Raspberry Pi to an LCD TFT screen, of which the datasheet can be found here: http://www.yslcd.com.tw/docs/product/N156B6-L0B.pdf
To summarise the specs:
- HD (1366 x 768 pixels) resolution
- 15.6" diagonal
- 3.3V LVDS (Low Voltage Differential Signaling) interface with 1 pixel/clock
- Can display 262,144 colours
- WLED
- LED converter embedded
I have attached an image of the problem I am having with it:
As you can see, there is an area of "smeared" pixels both at the right (shown by the folders) and at the bottom (shown by the grey of the task bar). At the bottom you can also see a duplicate of the mouse pointer, meaning the video output is repeated too.
The following shows the code I have placed in the config.txt file of the Raspberry Pi to configure the HDMI output correctly (one option being that DVI mode is required):
disable_overscan=1 #disable overscan (removes large black borders)
hdmi_force_hotplug=1 #forces HDMI output even if hot plug pin is not asserted
hdmi_drive=1 #normal DVI mode (no sound)
hdmi_group=2 #specifies that Display Monitor Timing (DMT) mode is required
hdmi_mode=0x51 #specifies 1366x768 60 Hz output
Without the disable_overscan=1, there is large black borders surrounding the whole video output (with no screen repeating). I have also tried on a different display (smaller but same resolution) and I see the same problem.
I've tried as many alterations to the config.txt as I could (including manually editing the overscan) and nothing seems to work.
Any help would be much appreciated as I've been banging my head against the data sheets for a while now.
Many thanks
Ryan