Jump to content
Unfortunately we had to take download section back offline temporarily. We should have it working normally soon.

Use a iPad retina screen for project builds

Recommended Posts

One of the guys on my forum found this great story thought it may work on someone build

In short, I've managed to drive the iPad retina display at maximum resolution from a regular PC with DisplayPort, no additional electronics required!

This is just a prototype, I'm working on a professional PCB with a DP connector so no wire splicing will be required in the future. :)

The screen

The "retina" LCD panel is LP097QX1-SPA1 manufactured by LG.

It's a 9.7" panel with a resolution of 2048x1536!

It's not exclusive to Apple, it can already be found in a couple of Chinese tablets.

What is great about this panel (except its resolution) is that it has an eDisplayPort interface (which is supposed to replace LVDS in the near future), and as this hack proves it is compatible with traditional DisplayPort outputs found on all modern video cards.

The panel is also surprisingly cheap - I got mine on ebay for $55, shipped from China.

Hoping that eDisplayPort is compatible with regular DisplayPort (I couldn't find conclusive proof of this), I went on to interface the panel with a DP cable.

Power and backlight

The panel itself can be powered from the DP connector, as it should provide 3.3V at 500mA, which is enough for the logic. Although that power is meant for an active cable, so I had to solder an additional wire to a regular "dumb" cable I was using.

The backlight requires some external power source, as it can consume up to 4.4W.

The datasheet is very misleading about driving the backlight, it only mentions something about "12V driver voltage", which is not the proper voltage (fortunately it's too low).

After finding iPad3 schematics, I've found out that the backlight actually requires 20V for operation, as it consists of 12 LED strings, with 6 white LEDs in series, each.

For the prototype, I didn't bother with a proper LED driver, just attached 68R resistors to each cathode, which resulted in a current draw of about 17mA per string.

The 20V was generated from a 5V using a TPS61175 step-up converter.


It works! No glitches at full resolution.

The whole thing cost about $70 in parts.

find more info here


Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...