I’m working on repackaging a framework mainboard in a different case and I needed a smaller display panel to make everything work. The iPad 7 panel is the perfect size, but there was essentially zero information out there on the electrical interface.
I spent a little bit of time reverse engineering the pinout and designed an adapter board that “bridges the gap.” The DisplayPort lanes are connected straight through, but the backlight arrangement is completely different, so my board also has a boost converter to power the backlight.
Pretty happy with the result. The panel just works now and doesn’t require any fiddling with resolution settings. I plan on posting all the design files once I get the main project to a more complete state.
I did not interface the touchscreen. This is just the display panel. I did look at it briefly, but the juice wasn’t worth the squeeze. The touch matrix is bonded to the coverglass on an iPad 7, so that glass panel would have to be cut down somehow. Also the interface IC on the Apple logic board seemed proprietary (or at least I couldn’t easily find anything on the open market that looked compatible).
Even without the touchscreen, that looks pretty good. What is the exact model number for the iPad 7 that you took the screen from? Looking forward to seeing framework builds with screens in smaller cases/builds. A Framework “netbook” with a 10 inch screen could turn out nice.
@ccRicers thanks! As far as I know all 7th gen iPads use the same display panel. The one I bought was advertised as compatible with A2200 and A2197 models.
I think this panel size/aspect ratio is about as small as you can get without running in to serious packaging problems (assuming you stick with a mostly unmodified Framework battery). I’ve already resorted to stacking components to make it work in this envelope.
@ccRicers The iPad 7/8/9 should be using the same LCD panel and digitizers, which fortunately are relatively cheap and available. I’m almost certain that the back case would have to be a custom part since the iPad motherboard is significantly smaller than the framework and the battery interface is completely different, but the idea of using Apple HIDs and displays is really neat and could really up the framework tablet feasibility.
Thank you! I wish I could say it was some grand adventure with xray machines, decapping, and microprobing, but the reality is far more mundane.
I found a snippet of a schematic in the depths of the internet that showed the pinout. I made some educated guesses about the LED string layout for the power supply design. I have no information on the mating connector, but you can buy no-name parts from eBay or Aliexpress and made up a footprint using calipers and a microscope.
I have no idea. That will depend entirely on the connector and backlight configuration. There’s no reason why it can’t be modified to work with a different panel (assuming it’s a four lane DisplayPort interface).
Impressive works. If you don’t mind, can you share about how much the board costed you? I want to recreate something similar myself, and wondering how much making such thing would cost me.
Also, is the board hand-soldered, or ordered to be assembled at the factory?
I paid about 180USD for 10 bare boards from PCBWay (4 layer, 4/4 mil trace/space, 0.2mm min hole). I opted for matte black solder mask and ENIG plating, which drive the cost up somewhat. If you don’t mind green solder mask and HASL plating, the same 10 boards would cost about 135USD.
I hand soldered the board. I have no idea what assembly would cost, as I’ve never used that service.
I ended up looking for panels that can be connected directly to eDP cable because I lack skills and money… Seems like for Thinkpad t21, I can use original framework screen as well, so I’m considering that as well.
@Karl_Buchka
What eDP cable did you use to connect this adaptor board to the Framework motherboard? I was able to find all the other parts to make this design with. Thank you!
