02/11/2015 at 21:35 •
So I finally found my hot glue gun and went crazy mounting the 7 inch HDMI screen to the project case I'm going to be using. It's off-center, but it is level at least.
I put electrical tape around the edges to protect the screen from the hot glue, and also to facilitate removal if I ever want to use the screen for a different project. I had to cut a hole with a razor to feed the ribbon cable that connects to the control board through the case:
I haven't got the power situation figured out yet, so I'm testing with a bunch of cables just hanging out of the case, lol.
Everything loads up just fine. I'm currently using the keyboard to interface, since the controllers aren't configured properly yet.
This screen is excellent, I couldn't ask for better, especially for the price. Here's a few more images for quality comparison purposes:
Now I just need to get the controllers working across all the emulators, and figure out what to do for power. I think I'm going to use one of Adafruit's products that supplies 5V from LiPos, but I'm gonna need a hefty battery bank to get the runtime that I'm aiming for.
08/24/2014 at 07:51 •
I have the screen working from the battery pack, but anytime the Pi is under load, the screen blanks out. The datasheet for the regulator states it can supply a full amp, up to 1.3xx with a good heat sink. So I might end up adding a heat sink, but I'm thinking hard about just designing a different switchmode power supply for better efficiency
07/30/2014 at 08:09 •
My screen came in finally, so now I have been working on an enclosure. I think I'm going to use a tackle box, laid out thusly:
I have a lid to a different box that I am using to protect the screen. I was going to use it for the project box, but it would be a tight fit. The old box and the screen are below, with the layout I was thinking.
The current problem I'm facing is the HDMI connection. I have to run it out from the Pi and in to the daughterboard for the screen. That daughterboard outputs to the screen with one of those ultra fragile ribbon cables, so I would like to have that board in a accessable place with the ribbon cable safely out of the way. I also have to deal with a huge connector on both ends.
The other problem is mounting the screen in general. I will prolly use hot glue to fasten it to the back of the bezel, and then maybe silcone to seal that to the lid of the tackle box.
07/14/2014 at 07:36 •
So after more internet research, I found a 7 inch HDMI screen that accepts 5 volt input. I got it for 51 dolla, sale blah blah link
It ships from China, perhaps I will have it before the end of the month, lol.
07/08/2014 at 22:47 •
I finally broke down and ripped out a 14.1 inch screen from an older craptop. I checked the model number against the list from this seller:
I'm not sure if it can be supplied at different voltages, the Engrish is very vague. But it has input for HDMI, VGA, and DVI, so it could be useful in a number of different projects. I searched for a dedicated HDMI solution for my specific LCD model, but to no avail.
A fourteen inch screen changes my original idea significantly. I originally envisioned a small box with batteries, screen, and a Pi with USB controllers connected. I soon decided on PS1/2 controllers since they are the limit of what the Pi can emulate, as well as being ergonomical and cheap to source. After the failure of the Chinese screen, I started thinking of the drawbacks to that design; mostly that the screen was too small to be utilized by two players, and that they were unreliable in general. I also thought a resolution change might be nice, so I did some research on small HDMI displays. There are options out there, top choices for me would be Adafruit's selection, or a recently funded Kickstarter, HDMIPi.
These were all too expensive for my project budget, so after further research into the problem, I found the LVDS converter. I have many junked laptops, and most of them still have good displays. Now the problem to solve is how to get this all hacked up in a portable package. I think I can find a tackle box with a clear lid to mount the screen on the inside of, facing out. If so, then batteries and Pi can easily fit in the leftover space behind it. Now I just have to figure out if weight is going to be a major issue. I'm an ultralight backpacker, so I have some extra space/weight for electronics that I love. But if I can't get it under 2 or 3 pounds, then it won't be worth it. The space constraint is a little more loose, I now see it with carabiner clips to facilitate strapping to a tree, so it can be clipped outside my backpack.
06/29/2014 at 13:47 •
I have seen an LVDS converter board for around 20 dollars on e-bay, and I think this might be my best option, as I have plenty of old laptop screens around, and I'm losing faith in these cheap chinese screens as a long term opton. Also, this would allow me to have a much higher resolution since it incorporates the HDMI connection. I think it still runs off 12 volts, but it has a 5 volt signal on the board you can tap into
06/21/2014 at 18:09 •
I tried a couple different things to fix the screen but to no avail. It still displays a white screen, but I can't get any signal on it. I haven't discarded it yet, but I'm looking into sourcing another screen for my final build. If anyone knows any h@x to fix this, lemme know. I think my next screen needs to run on 5V, to simplify power. I would like a 5 inch screen for multiplayer readability, but we'll see what I can find
06/07/2014 at 15:58 •
The backup cam LCD that I was using is now just displaying a blank white screen, and I can't think of any reason why. I guess there's no other choice now but to crack it open, try to fix it, and if that works, see if it can possibly be powered from 5 volts. Otherwise I'll have to pick up a different screen. Remember; if you buy quality, you only cry once