Tuesday, May 28, 2013

The Retina saga continues

Thank you all for your interest in my Retina-DP adapter. I'm still working on it.
I doubt I can make it a commercial product, but I hope I can at least make a design that is easy and cheap to reproduce.

For the next prototype I have designed a very simple two-sided PCB - just a DP connector and panel connector, with backlight lines brought out on a pin header (to be able to test different backlight solutions) and resistor footprints for the simplest possible backlight driving.
I designed the PCB in Kicad and had it manufactured by Smart Protoyping.

Swicthing over to Kicad from Eagle was a major pain, but after a few days of cursing I got used to it. :)

The PCB and Smart Prototyping review

This was my first time ordering PCBs from Smart Prototyping and I'm very satisfied with the results.
Their prices are basically the same as those of Itead and Seeed, but they offer some interesting services, such as cheap stencils.

The order was shipped 8 days after placement, and shipping via HK registered mail took only 5 days!

The boards came out fine, the design was within safe specs - 8 mil traces with 10 mil spacing.

Two surprising things happened: first of all, I have receiveed 11 boards for the price of 10!
Secondly, they have fixed my silkscreen for me - I had left resistor names between the pads (that's where Kicad put them by default), and somebody moved them to the side so they don't get covered by the resistors.
This was fine for me, since they actually helped, but someone else might have been upset that they messed with the gerbers.

Here are some shots of the boards:

Both sides of the board

Silkscreen, 1mm height

The DP connector pins have less spacing than the recommended 10 mil, but still came out fine

Some vias (12 mil drill, 18 mil diameter)

Some more vias

If someone is wondering, here are my settings for generating gerbers in Kicad:
 You have to draw the board outline on the Edge.Cuts layer and then rename the resulting .gbr file to .gml


Results

Soldered and connected
The board works fine, it's obviously much better than the previous one.

Here's a picture of Battlefield 3 running at native resolution:


I will work some more on the design, try to add some backlight control and switching regulators
My goal is to create the cheapest possible board for this, I think it can be done for less than $40.

I don't have the money to invest in the production of this thing, but I think I'll just release the design when I'm done and maybe sell a couple of hand made boards.

In the meantime, I can part with some of the PCBs from this batch, if anyone's interested in soldering their own adapter. Sorry, I'm all out.

The design files of this board (in Kicad format) are on GitHub: https://github.com/Emeryth/iPad3_lcd
The board uses a Molex 502250-5191connector for the panel FPC, and a MC34467 DisplayPort socket.

47 comments:

  1. Hi Andrzej, congrats on the updated board!
    How well did the soldering of the FPC connector go? I see you omitted solder mask between the pins.

    I did up a board of my own, inspired by your last post and the simplicity of the embedded DisplayPort connection on the screen.
    http://i.imgur.com/2mxRlfz.png is the eagle render, and http://i.imgur.com/YxEdhvE.jpg are the produced boards. These haven't been built yet, waiting on a few parts (slow postal service as always). I noticed a couple small mistakes on my board but it should work as intended. I plan to eventually do another revision if people are interested. These boards cost $17 each in parts + pcb to produce. I am using several sample chips to save costs on this prototype run.

    A future version of my board would be 4 layer and use different chips for the backlight control, but the cost would be under $30.

    If anyone has any questions you shoot me an email at henry@tehserv.net. I will be posting more information on my site rmmod.net soon, including my schematics and brd files.

    ReplyDelete
    Replies
    1. Your comment was classified as spam, try using less links and dollar signs ;)

      Soldering the molex connector went smooth with a regular iron, it was certainly easier than on a home-made PCB.
      But the lack of solder mask was not in my design, they must have done it when they messed with the gerbers.

      You've got a nice board there yourself.
      Better get it ready for mass production, because you will be swimming in requests for eyefinity kits :)

      Delete
  2. Wow, thanks a lot, I might try it myself since I have a broken Ipad but the screen still works.

    ReplyDelete
  3. How did you manage to solder the molex connector by hand? Also, OSHPark does services for mini boards for about $10 for 3 four layerboards of that size.

    ReplyDelete
    Replies
    1. I soldered the molex connector using a regular soldering iron with lots of flux and a desoldering braid for backup.

      The pins of the connector stick out a little from under the plastic, just enough to touch them with the tip, also the plastic is heat-resistant, so it won't melt during soldering.

      Delete
    2. I've been trying to solder this connector for an hour now and no dice, I've been trying for far too long and I'm getting frustrated... if you are looking to sell a assembled board I would buy it off ya.

      Delete
    3. Got any solder paste?
      if you do, you could dab it on the pins or pads for the connector, and hit it with a hot air gun, frying pan, or toaster oven.

      If not, all I can recommend is lots of flux like Emeryth said.

      Delete
  4. Great project! I'm stoked for the possibilities of screens imbedded in my bar at home. Will this drive the iPad 1 lcd?

    ReplyDelete
    Replies
    1. Nope, only the iPad3 retina panel - LP097QX1-SPA1.

      Delete
  5. Cool, I'd be interested in the new design with the backlight control. What is the process for getting one of the spare PCBs you have right now, if I want something to play with in the meantime?

    ReplyDelete
    Replies
    1. Just send me an email with your mailing address.
      I'll send you one for free.

      Delete
    2. Hello can you send me one spare part ? I can pay via paypal. I will like to use to build a projector. Is not need for back lighting resistors or controller.

      Delete
  6. can you hook this up to like a dvd player or other 1920x1080 device and show how it acts? Thanks!

    ReplyDelete
    Replies
    1. You can only connect it to a DisplayPort source.
      It does support lower resolutions, it just scales the image like any other LCD panel.
      I can't take any more pictures right now, I gave the panel to my friend who commissioned this project.

      Delete
    2. what about using an HDMI to mini-DP adapter?
      http://www.pccasegear.com/index.php?main_page=product_info&products_id=14692&cPath=625&utm_source=googlebase&utm_medium=cse&utm_campaign=export_feed&gclid=CID2x-Dr87cCFcZapgodc3QAow#googlebase

      Delete
    3. Unfortunately you can't do that, HDMI doesn't support the DP format... DP will support the HDMI format. If you want to convert to HDMI from DP you need some conversion electronics.

      :S Yeah I know, I wish it would be that simple.

      Delete
  7. I'd definitely buy one of these if anybody offers them for an acceptable price :)

    ReplyDelete
  8. 2 questions...

    What did you use as power, and what voltage and amperage?

    Did you solder a Displayport female header to the board, or just cut the wire, and is the board's current design compatible with a header?

    Thanks!

    ReplyDelete
    Replies
    1. You need 3.3V (at about 400mA) for the panel and 20V (at about 200mA) for the backlight.

      For example, I'm using a 5V/2A power supply connected to a 3.3V linear regulator and a 20V step-up switching regulator.

      This board has a footprint for a MC34467 DisplayPort socket, no cable cutting is required.

      Delete
    2. Thanks for the info! Was wondering if you could give a list of components mentioned above, and a diagram of the layout? Tried to find what i needed on my own, however feeling more and more like I'm going to fry it all to hell when the board gets here, and that would be sad =(.

      Thanks so much!

      Delete
  9. If I'm interested in buying more than a dozen, how many can you make at what price? And how many does it cost to ship them to The Netherlands?

    ReplyDelete
    Replies
    1. I'm sorry, I'm unable to manufacture any at the moment.

      Delete
  10. ... someone produced:
    http://dp2retina.rozsnyo.com/

    ReplyDelete
    Replies
    1. I prefer this board. Simple, Cheap and it does exactly what I want. Thanks Emeryth!

      Delete
    2. Thanks for the link though. :)

      Delete
  11. I wonder if Apple is using the same eDP interface inside their retina laptops. I'd love to get my hands on a 13" or 15" retina display. Great work Emery

    ReplyDelete
    Replies
    1. Had the same thought, however was unable to find any displays.

      Delete
    2. laptopscreens.com has them, but they aren't cheap. 250 dollar minimum on retina 15", and 400 for retina 13". The ipad one is the most cost effective.

      Delete
    3. LCD SCREEN FOR GOOGLE CHROMEBOOK has 40 pins connector it may be compatible with LVDS cables.The pins are larger then at the IPAD3 LCD
      model: LP129QE1 SPA1
      interface eDP
      Price:
      US $64.99(ebay) 28 to 50 USD (alibaba)
      Resolution (Pixels): 2560 x 1700

      Delete
    4. This LCD is a good candidate instead mac retina display!
      Almost the same resolution at a fraction of the price!
      The price is almost the same with the Ipad 3-4 LCD but better resolution and more convenient dimensions for watching videos and films.This post is for you Keith Wakeham.28 USD instead of 400 USD for almost the same performing LCD.12,9 " instead of 13" is not noticeable.

      Delete
    5. I can only find that display for 130 USD on Aliexpress? (I do see the 65 USD on ebay though).

      Delete
  12. Is it possible to purchase the LCD panel in a 13 or 15" retina display macbook pro and create monitors out of them? I'd love to take 2 15" MBPr display panels and turn them into monitors. Thoughts/

    ReplyDelete
    Replies
    1. Possible? Probably.

      The issue is the lack of a datasheet on those displays.
      Another thing is that they ship without a FPC cable like the one on the iPad display. These FPC cables are very expensive to manufacturer.
      If you buy one of the whole rMBP screen assemblies I imagine you could use that FPC cable.

      I'm going to pick up one of those assemblies and start testing soon.
      Based on the pin count it seems they are embedded DisplayPort as well. I would need to determine which pins are the signals, and then the power and connections for the backlight.


      Delete
  13. I think you could easily roll to kickstarter with this.

    ReplyDelete
    Replies
    1. The same ! Must do it and I buy instantatly 5

      Delete
  14. Looking good! I just requested a sample of two connectors from MOLEX for this. Do you think it would be feasible to add a 5v -> 20v boost converter so it could be powered via USB or would that be pushing the 1A limit of USB specs? Also, would a simple 555 dimming circuit be easy for light control or should a more complicated current limiting IC be used instead?

    ReplyDelete
  15. Ok, so I followed the tutorial on how to get the gerber files from your schematics using this tutorial

    http://hackaday.com/2009/01/15/how-to-prepare-your-eagle-designs-for-manufacture/

    then I put those gerber files in a zip and I just upload those to smart prototyping correct?
    would it be possible for you to email me a zip of the gerber files you used?
    I would feel better about ordering them if you did
    I don't feel confident using the ones I made.

    dwight.j.doane@gmail.com

    ReplyDelete
  16. https://plus.google.com/u/0/112526208786662512291/posts/Tdqf4BeLQVk

    Looks like Adafruit will be making some :)

    ReplyDelete
  17. You are awesome! Great work! But will this adaptor work with another retina displays with same size and resolution but different manufacturer?

    ReplyDelete
  18. Any idea if you could do the same thing with an iphone screen? Does it also use edisplayport or the LVDS thingy?

    Keep up the good work!

    Regard,
    K.

    ReplyDelete
  19. Hi there, you can using smart-prototyping also doing the BOM sourcing and assembling testing. This will save your time and money which is produce in China.

    ReplyDelete
  20. To solder this connector is pain in the ..
    I cud not solder it. The PCB tracks are to fragile.
    If somebody have an PCB made in a industrial factory let me know.I want to be cheap and easy.I am not enthusiastic for fancy converters for LEDs.
    Maybe it is a way to buy already made PCBs with the connectors soldered.

    ReplyDelete
  21. LCD SCREEN FOR GOOGLE CHROMEBOOK has 40 pins connector it may be compatible with LCVD cables.
    model: LP129QE1 SPA1
    interface eDP
    Price:
    US $64.99(ebay) 28 to 50 USD (alibaba)
    Resolution (Pixels): 2560 x 1700

    ReplyDelete
  22. excellent work.

    It was what I have been searching for.

    How many will be interested in getting fully assembled board? I need one to my self

    catch me on Fagtekniker@gmail.com

    ReplyDelete
  23. Great job, enjoyed reading
    stan@digital-play.com

    ReplyDelete