Wednesday, November 12, 2014

iPad mini 2 retina LCD to DisplayPort adapter

UPDATE 2015/04/12 These are now available in my RC junk shoppe.

Been meaning to innovate this one for a while, but nobody had datasheet for the board to board connector that the 7.9" iPad mini 2 (2048x1536 retina) LCD used. Finally caved in and bought some from a random Chinashop (about $80 shipped for MOQ, ugh), scanned them, used amazing augenmass tool to calculate dimensions, and made a PCB hoping it would work.

Keen arduino developers will notice there's some extra circuitry which will be a subject of a separate post, however it does appear to function after some quick testing.

I basically copypasted the circuit from the other adapter, removed one of the backlight drivers (this panel only needed 6 channels), added a little innovation, and routed it all within a few hours, because I had some free space on a FR4 panel that I could add a couple boards to. For some reason LCD module wanted to be running at 3.6-3.7V instead of 3.3V, so I gave it that.

Assembly was pretty uneventful, and the annoying fine-pitch FPC connector actually matched my "guessed" footprint and soldered correctly. The board powered up on the first try, and nothing seems broken so far. Current draw at full brightness is a nice 510mA.

I used MicroUSB for power this time (again with external 5V on pads if needed), and the same huge full-size DP connector. All my attempts to source a decent MiniDP connector that wasn't a complete pain in the ass to solder didn't end well. I got some samples that were half-smt half-through-hole but there was about 3 or 4 different vendors for those and each one had slightly different layout for mounting pegs, and I didn't have time to sample them all to find out which one was the most commonly used. Molex also has a all-through-hole one, but it didn't seem to be very available either. So, big size DP for this one.

I quickly ported the firmware from the other displayport adapter to run on new board, so it basically has the same functionality. On the new PCB I added a pad for the button signal so that the power/control button can be placed outside a case or similar, if required.

Here's some pics of first finished board (I only made one).
Full-resolution pics are in picasa album here.

Close-up pic. See if you can spot the innovation.

I should have probably taken a pic next to my phone for size comparison, but this credit-card sized thing will do instead.
My pal told me I should have drawn a dickbutt on it with marker, but it's too late. Missed opportunity. Maybe I'll do it for the kickstarter promo video.

Backlight + power ON. The board fits behind the LCD, and with default landscape orientation, USB + DP connector are on the top.

Backlight off, "standby"

Drawing a cool 510mA at 5V

This looks pretty small compared to my two Dell UP2414Q
No promises on availability, but I might make more than one at some point.

31 comments:

  1. I want to buy this product in stock when the trouble to contact me mail 15911113976@139.com

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  2. Do you really plan a kickstarter for this? Any plans for when? If you can make it for around $30 a piece I'd definitely take a couple.

    Are you aware of any phone LCDs that use eDP? Those would be great for a camera viewfinder or a low cost VR headset.

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    1. No, the kickstarter reference was to this failed attempt https://www.kickstarter.com/projects/935235616/minimax-the-portable-professional-high-dpi-display where they wanted $130 for a led driver PCB

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    2. Oh, saw that at the time, and had a similar thought. I bought a couple of driver PCBs from abusemark from Japan, which turned to be pretty nice.

      However, the iPad mini LCD is more interesting as its easier to handle as an external monitor on a small camera (Sony Nex, Panasonic GH-series). A case for it can also be easily made on most 3D printers (200x200mm print bed).

      I still think its worth making into a product, if you can make it financially viable at around $30.

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    3. well, that particular camera happens to not have displayport output :)

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    4. DisplayPort and HDMI are compatible though?

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  3. If you are not going to produce any could you share the schematics for personal use?

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    Replies
    1. I finally got unlazy and submitted PCB panels for this stuff.
      So it is happening. btw, this is trivial, so anyone who would actually know what to do with a schematic could just do it in a day with a panel datasheet and common sense.

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  4. Any idea when it might be available for sale?

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    Replies
    1. I guess next week, I'm just waiting on LCD connectors, all other parts are here already.

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  5. Will this screen work?

    http://tinyurl.com/l8apnmy

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    Replies
    1. Looks right. I think thats about how much i paid for mine.

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  6. This comment has been removed by the author.

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    Replies
    1. Bought one! How long will shipping take to US aprox? Thanks!

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    2. This is really not the place for asking these questions. The place you bought them from has an "About shipping" page which you should read - it explains all this stuff.

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  7. Hi,

    is it possible to use Ipad mini 1st gen scree on it ?

    Regards

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  8. On the store page you link to it says may not work with some intel built in graphics, do you know if it will work with a Mac Mini. Are you aware of which intel graphics do not work?

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    Replies
    1. Hiya,
      I don't know. I have a 2011 Mac Mini but its the i5/2.5GHz version with ATI graphics. It works there.

      I don't have the time or resources to test intel onboard graphics, I got a couple reports of it not working, so I just say it doesn't work with ANY intel graphics.

      You can go ahead and research for yourself :)

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  9. Heeyyy! Is there any chance you do a HDMI version?

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  10. Hey I'm interested in the 7.9 inch adapter for the ipad mini lcd. Any chance you've gotten a touch screen to work with something like this?

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    Replies
    1. well what do you mean "got to work"? you can buy resistive or capacitative touchscreen overlay and just use it, they can come with some USB controller or something. I don't have a lot (= read: none) of interest in touchscreens so I haven't looked into it.

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  11. Hi, is compatible with LP097QX2 (iPad 5th LCD) ?

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    Replies
    1. Not yet. I'm making those right now. Probably available next week sometime.

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    2. Hi timmy, do you finished for iPad air LCD ?? if then can I buy it now ??

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    3. yes, its been in my shop for a week now - http://abusemark.com/store/index.php?main_page=product_info&cPath=3&products_id=55

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