Retro LCD - a Perfect 4:3 Retro-Gaming Experience

by WhoIsLudwig in Circuits > Gadgets

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Retro LCD - a Perfect 4:3 Retro-Gaming Experience

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Retro-gamers rejoice ! Finally a nice 4:3 aspect ratio, lower lag LCD display in a small footprint. By using replacement iPad 3/4 LCD panels, it is possible to make a very nice screen, perfectly suited for those older games. Those screens are very high resolution (about 2K in 9.7 inches), which makes it very flexible for use with modern upscalers. It uses a Mini-HDMI input so you'll need a way to feed analog video though HDMI, such as an OSSC or a RetroTINK, providing a near perfect display quality. Power is delivered through USB Type C and there also is a separate Display Port capable USB-C input, for single cable operation, if you have a compatible device.

The case has a folded standing foot that can be opened up to about 50 degrees, allowing a very stable and flexible display experience. Combined with the very large viewing angle and high quality of the iPad display, it's an extremely convenient way to play 240p and 480p games, even on the go, if you have one of those fancy emulation device.

Note : The case doesn't include internal speakers, but the controller PCB board does have a 3.5 mm audio jack, allowing to use headphones or external speakers very easily.

Supplies

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Here is your laundry list for this build :

  • An iPad 3/4 replacement display along with the driver board. Those displays are widely available on AliExpress for 50 to 60 Euro / Dollar by the time I'm writing this. Here is the link where I bought both my displays. They both arrived pretty quickly and very well packaged.
  • The 3D printed case. If you have a 3D printer, it's pretty easy to do. If you don't, you can find excellent 3D printing services online (such as PCBWay, JLC PCB, or a local 3D printing workshop). I left detailed printing instructions on the Printables / Thingiverse pages.
  • 10x 5mm long M2 hex head screws (6 and 7 mm should also work)
  • 10x M2 brass inserts
  • 2x 20 mm M5 screws
  • 2x M5 nuts
  • A soldering iron to push the bass inserts (any cheap iron should do, as long as it has a fine enough tip).
  • A pair of pliers
  • A mini-HDMI to full-size HDMI cable or adapter is needed to connect the video source to the display.
  • A good USB Type C cable and power supply. The cable provided with mine didn't seem to work fine, but it might be just mine that is faulty. I used another Type A to Type C cable that I had laying around with a phone power supply and it worked just fine.

Testing the Display

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Upon reception, it is usually a good idea to try the display in order to ensure it does work as intended before you even start the build. This way, you eliminate the possibility of working with a faulty display and having to start everything over. You never know what can happen during shipping, and faulty units do happen from time to time.

First connect the "Flat Flexible Cable" (or FFC for short) that comes from the panel itself to the driver board by gently lifting the black connector tab, inserting the FFC inside with the blue tab facing up (pins facing down), then locking the tab back in place. Be gentle on the tab as it can break pretty easily if you put too much force on them, and it's a pain when it happens. the FFC itself is quite resilient, as long as you're careful.

Now connect a video source on the mini-HDMI input and power up the board by connecting your power supply to the leftmost USB-C port (with the ports facing away for you). The board should power up, the led should turn green and after a couple of seconds, the display should turn on. If it doesn't, check your connexions, try to use a different power supply and cable, make sure the video source is active and try again.

If everything works as intended, entirely disconnect the board (the cables and the FFC) and proceed to the next step.

Note : It may also be a good idea to test the fitment of the 3D printed parts, especially the pins holding the front frame and the inner wall together. This is pretty tight, and it may be a good idea to ensure they fit together nicely without risking damaging the display inside.

Prepping the Front Frame

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Before mounting everything, it is necessary to push the brass inserts into the front frame. They ensure a good grip on the screws, since threading directly through 3D prints is usually not advised, especially with PLA.

First turn on your soldering iron. If you can, choose a fine tip and set the temperature to about 200°C (390° F). With a pair of pliers, hold the insert straight on top of the hole. Then, gently push the insert down the hole with your soldering iron. Push the insert until it's flush with the frame surface. Don't apply too much force, just a little weight should be enough. While heating, the insert will slowly go down while the surrounding plastic melts.

Remove the iron and let the brass insert cool down for a few seconds before touching it.

Repeat the operation with the 10 holes (4 on each side and 2 on the bottom, see the included picture).



Placing the Panel

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When it's done, remove the protective film from the LCD panel and put the screen inside the frame, facing down. It may be a good idea to place a cloth or a silicon mat under the frame to prevent scratching or damaging the screen itself while working any further on the back.

If you want, you can use the pre-applied adhesive to fix the screen to the frame. Feed some fullscreen pattern, such as the boot pattern of an OSSC to the display in order to ensure the centering of the image, remove the red protective film from the adhesive, make sure the image is straight and centered and stick the panel to the frame. It will make it permanent though. It is some strong adhesive and trying to pull it off will end up permanently ruin your LCD. it is very optional, and personally, I never used that adhesive. The screen remains very stable without it, since there is not too much wiggle room inside, especially when you use the optional tab holders.

If you printed the four corner tab holder, you can put them in place. Simply insert them in the corner slots. Put the slightly smaller one on the bottom right corner (the one facing down, towards you) and the three others on the remaining corners. This is also optional and only serves to ensure the display will remain nicely in place when closed.


Inserting the Board

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With the display in place, you can go ahead and put the "Inner wall" part.

First, slide the FFC through the dedicated slot. The adapter board should fit right under the holding tab. If necessary, relocate the adhesive holding the black ribbon cable on top of the screen upwards or downward is order to prevent the board from moving around.

Slide the wall to align with the frame and then insert the 6 tabs of the frame into the holes on the wall by pressing down on each hole. Make it so the tabs are as flush as possible with the wall surface (it might not be perfectly flush, but it's alright). Press directly on the holes / pins upon the side and NEVER on the plate itself. You don't wanna apply too much force on the LCD back and risk damaging or even breaking it. Ask me how I know ...

Use the two M2 screws that go to the lower side of the case to keep the wall in place.

Now, insert the driver board. First slide the connectors and the control rocker through the holes, then push the back of the board down so it is flush in its holder. There is very minimal tolerance here, so it may be necessary to bend gently the case in order to fit the top of the board inside its case.

Alternatively, it is possible to simply install the board before putting the wall on the frame. Once the board is inserted in its housing, it is quite firmly held in place and shouldn't move around easily.

You may also need to shave a little bit of plastic in order to fit the connectors through the cutouts. It seems like sometimes, there is a slight offset between my initial measurements and the actual board. However, I increased a little bit the tolerance of the cutouts, so it shouldn't be a problem ...

Folding the Cable

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Now comes the time to connect the board and fold the FFC.

First connect the FFC to the driver board exactly like you did during step 1. Remember that the blue tab should be facing up. Then, fold the FFC in such a way it remains within the boundaries of the case, materialized by the raised edge in the middle of the wall. You can find the inspiration on my own origami, but in the end, you do as you see fit.

What's important ultimately is that the FFC remains in place and that it doesn't get pinched when closing the case.

Remember to be gentle. Those flex cables are meant to be folded, but not to be creased. So when you push, don't put too much strength on the line. Just enough to imprint the shape without breaking the somehow delicate connexions inside. It's not that hard, really, just be gentle, take your time and it should be alright.

Feel free to observe the included pictures. That folding really worked well for me. Also, it's really easier to fold with the FFC connected to the board. That way, it naturally falls into place

Then, you can tack the cable in place with a piece of adhesive tape (I used Kapton but you can use whatever you have) and proceed to close to case.

Before you proceed with closing the case, now is the right time to try plugging the display and to confirm that everything still works.

Closing the Case

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You can now close the case by putting the back plate on.

First align the clips of the top of the frame with the slots of the case, then put the case down, making sure the border ridge aligns with the inner wall

Now use the 8 remaining M2 screws on the sides of the case to close everything down. You don't need to overtighten, just enough to keep everything nicely in place.

We're almost there !

Installing the Foot

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This is the last step.

First put the foot in place. Check that the two lower screw heads align with the corresponding holes on the foot.

Take the two M5 screws and the tubes that you printed (whether standard or "TPU") and insert the screws in the tubes. You may have to thread the screws inside the tubes. It's alright and it doesn't matter if it's tight.

Insert the screws and the tube in each hinge channel. Put the nut on the other side and start to screw. Don't tighten yet. Make sure each nut is correctly inserted in its slot. When both nuts are correctly engaged in their slots, use an Allen key to strongly tighten both sides.

Try to manipulate the foot and observe the screws while doing so. It is important that they do not rotate when you manipulate the foot. If it does, try tightening a little bit more. The foot should feel slightly restrained, enough to be able to hold the whole assembly straight when raised. If it does, congratulations, your Retro LCD is complete !


Be sure to use the right type of tube for your material type. "TPU" tube is slightly longer than the channel, so using it in place of the standard one will result in an unstable foot. However, if you can, I strongly recommend that you use this flexible one, since it does provide a much better experience and is overall smoother and more reliable.