LED video wall, donated by a local non profit

I had a look at the panels today and confirmed that you can swap out the bad modules for good ones and its literally swap, plug and play.

There are 8 screws on the inside, you’ll need a philips #2 stubbie to get at the modules on the edges of the panel (couldn’t find one in the space). After that there are two ribbon cables that have press in clips on the end, and one molex power connector. Thanks to Janet’s warning about the panel falling out I discovered that if you leave the molex power connector connected while you undo the screws it makes a dandy handle for keeping the panel in place and also lifting out the panel and pulling it back inside.

I started robbing the working modules from panel #3 and moved a couple over to panel #8. So now #8 and #2 are fully working. The next low hanging fruit are panels #1, #5, #7, each with only 2 faulty modules. So if someone gets bored and wants a project… Bonus points if you mark out which pixels are dead before pulling the module out so we can fix them easily.

Also the donor found another box of goodies which apparently contains more individual modules. They will be dropping it off on Friday.

I am currently thinking we should put 4 up on the wall of the paint and mess room facing the lounge and 2 on the back wall of the classroom upstairs (raised up so chairs don’t wreck them), but we will have to see what the power consumption is like when we dim the panels.

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Awesome thanks for doing that! Great that are so swappable! I’m still out with teh sickness but hope to get back to fixing up the borked leds next week.

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Haul pics, Matt was nice enough to drop off another box of parts for the ultramegajumbotron.
Looks like about 30 more modules, a sender card, and a bunch of power and data cables. No idea what is working but we can figure it out.

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Amazing! So much sweet led candy.

That’s… legit amazing.

So… you guys… like… its here!


So beautiful, should have sent a poet.

And Lee’s had all the other do dads I forgot I needed to get to make this thing work.
20191109_100923

And now to figure out how to program this thing… Wooooooo!

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Oh my god - amazing. I love how happy you are. Looking forward to seeing what we can do with this baby. Report back!

Does it need a PC to work?

So update on this, had the sender card work briefly out of the box, then some dumbass hit the update all button to attempt to change the resolution settings which overwrote all of the led driver configuration and borked the whole thing. @rsim and I spent a few hours trying to figure out rhyme or reason to the led driver configuration settings and its obtuse and capricious.

Basically, this sender card can talk to a whole pile of different LED receiver/decoders. Thus it has really really complicated settings that do strange things. It can even talk direct to shift registers, or any one of about 30 different types of LED drivers (but noteably not the ones we have, at least in the version of xmplayer I am using). You can adjust timing, phase angle, pwm on time, latch signal duration, refresh rate, and more, even down to non standard bit and pin order. We managed to get it where there was a blurry dot that corresponded to mouse movement, and some things that kinda looked like the windows we were using, but we couldn’t replicate it even after setting the same settings back.

Some facts though: the sign modules are made up of jxi5020gf led receivers, here is the data sheet with timing details:
https://datasheet.lcsc.com/szlcsc/1810010214_MBI-JXI5020GF-B_C82599.pdf
the decoders are 138bs when that popup config box comes up.
this is the manual for XMplayer (the software that configures the sender card and can also set up slideshows)
http://www.ledcontrolcard.com/download/dbstar/dbstar-XMPLAYER%20control%20user%20manual.pdf

and another that goes into more detail about some of the advanced settings:

I have emails into the manufacturer, and the company that sold me the card. There is also a local shop that sells these led signs that I can try to implore for assistance next week, I am going to sleep on it and maybe try again tomorrow.

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Just found this. perhaps?

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So this happened:

We now have a running video wall (for values of running that include the fact that I only connected one panel and haven’t tested daisy chaining them).

There are a few caveats

  • The receiver cards are preconfigured with the right led driver settings
  • I can’t seem to download those settings to my computer so we have a copy of them
  • There is one button in the configuration program that causes the sender to overwrite the receiver card configuration with the one stored on the computer.
  • This button is located immediately to the left of the exit button
  • This button does not have a confirmation dialog
  • Pressing this button causes the receiver card to no longer work. (it can be fixed if we figure out the correct configuration settings)
  • This happened to one of our 8 displays
  • If the sender is connected to our other 7 displays and this button gets pressed, we will have 0 working displays

To address this issue I have been plugging away on the borked display to figure out the configuration settings some of which include

  • Driver is the MBI 5124 - which is apparently comparable with our actual JKI5020 drivers
  • Decoder is 138b
  • Data Polarity is normal
  • I forgot to write down the timing and other settings because my brain was melting
  • Dispite the fact that our screen is 112x128, you cannot set the display output to that number, it will not work, at least one of the values needs to be > 195. I do not know why.
  • This causes the screen to offset all its values roughly 80 pixels to the right and makes it impossible to figure out the LED sending order
  • By sending order I mean, when you clock in the first bit, which led lights up. You have to figure this out for all 16 rows and columns, or 256 times. Its not in order left to right, it seems to go 1 near the top right, then down 3 rows and 3 columns over, then back up beside the first one, etc. Have fun!
  • I got it as far as you can recognize that its a screen, and it more or less works, though the pixels jump around and are not exactly in the right order, which is a hell of a lot better than the insta-seizure giberish it comes up with if you aren’t even in the ballpark of the correct configuration.

You can globally dim the display, which is cool:

  • at full brightness and full white (255) each panel will draw 8 amps of 110v ac
  • Dropping this to 83, results in an entirely acceptably bright display that draws 2 amps.
  • 30 gets you to 1 amp, but seems a bit dim, still usable
  • there is no system wide lockout to prevent the brightness from getting set to max.
  • you need to use the usb port to adjust the brightness so that is a plus. But you don’t need the usb to display something.

This means that we can run 7 panels in a row, and draw about 14 amps, if you set all of them to full white.

Also, this is 83 brightness in the space with the lights on:

Yeah, acceptably bright.

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Quite amazing looking!!! Well done! Are you still detaching the power plug after working on it - or can anyone just plug it in and away it’ll go? Like - if I plug this baby in and hit reset will it run all the He-man?

Think of it as a giant monitor, with a special magic box that converts the monitor signal to the format of the panels.

Once hooked up it will basically mirror not quite the top left of whatever computer its hooked up to (provided that computer has a DVI or HDMI port).

Right now the sender card is the little red card with the wires going into it that sitting on a cardboard box next to my lunch and plugged into a 5v wallwart. I plan to come up with some sort of case/enclosure/upgraded cardboard box for it so we can just have a thing that you plug a computer into when you want to display something. For now I stashed it into my tote, there are several ways to screw up the panels with that thing, most of it fortunately requires the configuration software and a password.

There might be a way to preload slide shows, but I am not sure how that will interact with a live display.

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So had a look at this the other day, @Jarrett pointed out that the reciever cards have a serial eeprom chip on them, a SST25VF080B:

He figures it should be possible to dump and copy the storage from a good card, to a borked card, but won’t have time to try that until late December, if anyone else wants to give it a go though feel free.

I am making some progress on the configuration but still have to fix the individual pixel assignment order, new plan is to connect our 2 malfunctioning reciever cards each to a panel and try to configure it that way to get around the pixels not showing up on the screen issue. Won’t be able to try that till next weekend though.

Also, I started a new thread (to avoid thread clutter) about where do we install this thing. Have a look here:

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So I have a sender card in a box now.

So yeah, you can hook it up and display youtube videos and what have you:

You just need to plug in the power brick, your DVI/HDMI signal, then a data line to the screen. Please don’t lose the HDMI->DVI adapter.

Like anything it ain’t perfect yet, so there are some notes:

  • data out one is set up to display a 448x128 area of your display starting from x200 y200
  • data out two is set up to display a 448x128 area of your display starting from x200 y328
  • you can daisy chain screens, it doesn’t seem to matter which of the two ports on the receiver you plug into
  • the screens don’t seem to chain like neopixels, they seem to have their location hard coded. Changing the cables doesn’t change their display position. I don’t yet know how this is set up in the configuration program.
  • This is why I marked one left screen (is display unit #2), and another right (its display unit #8).
  • 2 and 8 have power and data cables connected now, to daisy chain them plug the data cable of one into the receiver card of the other (you will need to open the back of the display)
  • I only tested this with a 1920x1080 display output, mirrored.
  • I only tested with 2 displays, I don’t know what horrors will be unleashed with more.
  • The amp draw should be only about 2 amps per panel so you can daisy chain them, If you are testing this, try to do it on a circuit with a breaker not a fuse.

As to the larger project of reverse engineering the configuration file, well, turns out that getting these things configured is a royal pain in the arse. So I am tapping out for a bit.

I got as far as the attached file. kinda working.zip (3.6 KB)
Which has the right driver, right scan rate, but the wrong pixel mapping (and the program insists on setting it up to be 32x16 rather than 16x16). If you are interested in taking this further DM me and I can give you instructions for how to download and launch the configuration utility. If you take it on on your own please:

  • ONLY TRY TO REPROGRAM THE ONE DISPLAY WITH A BORKED RECEIVER CARD

  • IT IS MARKED WITH TAPE THAT SAYS “HAS BORKED RECEIVER CARD”

  • WE DON’T NEED ANY MORE BORKED RECEIVER CARDS

  • REPROGRAMING WILL REPROGRAM ALL SCREENS CONNECTED

  • DONT SCREW IT UP

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Just found out that the Luminescence V show application deadline has been extended to Jan 22nd. Someone might be interested in getting a giant game of pong together for this show? Always a popular one. Deer Lake Gallery.

https://www.burnabyartscouncil.org/luminescencev/

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Would be great fit for this show!

So the screen is running, I got windows installed on one of our old core 2 machines, its slow but functional thanks @laftho for the help with that. The pc is beside the couch. Feel free to fire it up, the password is written on top of the machine.

If the screen doesn’t come on automatically there is a program on the desktop called I think “Turn screen on” that you can launch to… well, turn the screen on. There is a button, its obvious, if you get a password prompt, that was the wrong button, don’t screw with anything behind the password (see posts above).

There are also snes and nes emulators and a roms directory on the desktop.

There are a few things I need help with if someone is looking for a project. I’ve put a fair bit of hours into this and am getting to the point where I would like to step back and let others take over. PM me if you need more details.

Off the top of my head though, on the list is:

  • Adding a speaker to it, or figuring out how to hook it up to our existing speakers, keeping in mind that it might move. - think I can do this through the chrome cast
  • adding wood to the side table and bench - plan is for 1/2" plywood (not mdf or particle board, need the strength as people will stand on this. Wood would have to be acquired), it would also need to notched at the back corner around the hinges
  • acquiring a couple game controllers - so far I am setting this thing up for SNES/NES games, @laftho hooked us up with a bluetooth dongle and I installed software to make dual shock controllers work but I don’t have any spare controllers in my kit. Wireless is best because you have to basically sit on the stairs to avoid getting nauseous. - ordering a couple off amazon jon offered to pay for one.
  • getting a wifi dongle for that machine - right now its on a long cable to the server room.
  • cleaning up the cabling and maybe re-configuring the power cable - right now the cord comes in from screen left, and is connected together inside the top left panel, we also need to power the pc and its monitor - I got it sorta working, but it needs some love and a bit more sensical layout. - got it rigged, see post below
  • figuring out some sort of swivelling monitor stand so the screen can pivot to the side but still clear the support leg. -support is sitting beside the monitor, needs attaching
  • configuring that computer to auto login and perhaps auto start the emulator program.
  • figuring out the receiver card configuration (see posts above), we have spare screens, one of which has a borked receiver card, if we figure out the correct settings it will allow us to change the refresh rate of the video wall which would greatly help with visual tearing and other issues. This is an advanced project, pm me for details or grab me in the space and I can knowledge dump it.

Other than that, the thing works, its basically a giant monitor, drag whatever you want to display to a spot 300 pixels down and 300 pixels right and it will mirror on the video wall.

I added a desktop image to the machine to help align your window to the display, basically anything inside the black square gets put on the wall.

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I can take care of some of these.

  • Wifi dongle on it’s way, got a spare.
  • I can take a crack at nice cable organization
  • Maybe speakers, depends on what I can find etc.
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Sweet, thanks Rob.
I got the ac repatched tonight, now you can just plug in the one cord on the left of the screen and it will power everything. The video wall itself is on its own switch.

Best to leave that cord plugged in and the computer running due to settings reverting. But if you need to fire it up after a reboot and the screen aint scaled right check to make sure the display is set to duplicate not extend, and check the video scaling is set to 100% these settings seem to change… Not sure why.

The new switch is beside the power cord

use this to turn off the video wall image and cut out all the fan noise when the screen is not in use.

Oh and I have a new desktop, thanks for the sugestions.

So yeah fire it up, would love to see what people come up with to display and play on our new photon cannon.

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