Giant video walls powered by a Raspberry Pi

There’s no denying that giant video walls are awesome, but creating one usually means a fairly complex setup with either multiple computers or very expensive video cards. Now, with Pi Wall, you can make a video wall as large as your wallet will allow with only one Raspi per monitor, and a single master pi to control the whole shebang.

As long as you have a few displays with an HDMI input, it’s easy to turn them into a giant monitor. Just plug one Pi per monitor into a network switch, have a Pi (or other Linux box) transmit a video to all the video tiles, and sit back and enjoy the show.

Right now there is an installation guide for creating a Pi Wall, but there are a few limitations; this software only works with the video player provided with the Raspberry Pi, omxplayer. If you’re looking to create an enormous display for a flight simulator or what have you, you might need to do a bit of tinkering under the hood.

31 thoughts on “Giant video walls powered by a Raspberry Pi

      1. Oh, and you can’t forget the little umbrella and a slice of lemon to stick on the lip of the glass. We’re not barbarians, you know. Standards must be maintained.

        (c:

        P.S.: Cool video wall.

      1. I worked on this display using XdmX in highschool. We built the thing with 12 display nodes and 1 server. It was a mess to configure and keep running. If I remember correctly, we used a special network that did nothing but the video.

  1. Aren’t most modern PC graphics cards now capable of this, even the cheap ones?

    DisplayPort allows daisy chaining, so as long as your graphics card has one or two DisplayPorts you could chain up a pile of monitors without a problem.

    Not saying this isn’t cool, but saying it requires an expensive / special graphics card isn’t entirely true. Even Intel Integrated Graphics 4000/2500 supports running three screens, can’t get much more low-end or cheap than that as a starting point…

    Using a Pi is also hardly a cheap solution, not when you need one per-screen. The wall featuring 9 displays cost $225, which is more than enough to buy a very nice graphics card with between 4 and 6 DisplayPort outputs (and each of those DisplayPorts can have 3+ monitors daisy-chained).

    1. $225 will not buy the computer to put the card in though.
      I know my TV doesn’t have DisplayPort, is it actually a common connector for standard tvs?

      This system has the benefit of working with almost any modern tv, and I’m guessing scalability would be a strong point of this system.

      1. Most people considering a video wall are pretty likely to already have a computer on-hand to toy around with. A computer is also (generally) required to get a Pi up and running, so you’d need one anyway.

        Most people considering a video wall will also want matched monitors, which generally means buying them all in one hit anyway.

        If you’re getting all new monitors anyway, might as well get DisplayPort capable ones (and yes, this can be easily found on TVs). Also possible to use cheap single-link active adapters to connect via DVI / HDMI.

        Graphics cards will scale better than this (after a point). Newegg has a Radeon HD 7750 for $249 that has six DisplayPort outputs, and each of those outputs can drive 3 monitors. That’s 18 monitors off one card, with a full PC’s worth of power to throw behind putting impressive visuals up ;)

        $249 with graphics cards = 18 monitors
        $249 with Raspberry Pis = 10 monitors
        $500 with graphics cards = 36 monitors
        $500 with Raspberry Pis = 20 monitors
        $750 with graphics cards = 54 monitors
        $750 with Raspberry Pis = 30 monitors

        And by that point you’re dealing with 30 Raspberry Pi’s instead of one PC, which can get pretty ungainly (and difficult to keep in sync and/or keep overall latency down)

        1. This is a pointless argument but you are still discounting the PC that the graphics card goes into. Arguing that you need a PC to get the PI’s going is beside the point, once they are going it is no longer part of the display and not a part of the cost of the display. Are you going to count the cost of the screwdriver, etc you use to put it up? The PC with the video card is a permanent part of the display, hence part of the cost, whether you had bought it previously or not. This makes the PC video card version always more expensive, but as you say probably easier to manage as monitor count goes up.

          And yes there are probably other/possibly better ways to do this, still an interesting project

          1. I’m not fully discounting it, but it’s not that big of an additional cost considering the additional power and flexibility you get from it. Potentially better latency and synchronization between displays, as well.

            And you’re missing part of the point I made when I listed the scale. The larger the video wall, the worse off the Pi does, until eventually there’s enough margin seperating the two solutions to cover buying a PC.

            On the small scale, a $250 PC with intel graphics can handle 3 screens. On the large scale, A PC with a couple decent graphics cards also blows this away on price vs performance/features. Using Pi’s has a very small niche where it makes sense.

          2. Leapo, after looking at the website for this project, it looks like one of the main advantages is that you can easily break down and reassemble the setup.

            Think about a portable videowall for trade shows etc, with the piwall, you could easily have 20 screens in the shop, and just take 9 to a smaller show. Since you could strap the pi to the back of each TV, all you have to do to set up is plug in all the network cables.

            Cost wise the piwall might be more expensive for a permanent setup, but you only need an extra rPi and network switch to be able to split the wall in two and take half one place and the other half somewhere else.

          3. How has no one mentioned that with the computer-based setup you also have the ability to do computing tasks on that large display. Work on multiple items, run powerpoints, etc, whereas with the Pi wall all you’re doing is playing back video.

            That all said I wouldn’t be surprised if the Pi’s video player supports streaming, and I’d bet there is a way to stream a “monitor’s” output to get essentially the same thing but likely with more overhead and latency.

        2. You’re neglecting the fact that not all monitors/cards/drivers support display port daisy chaining, let alone 3 displays per dp port… Good luck with that. Also a mainboard having enough 16x PCIe ports AND enough space (the Radeon HD 7750 looks like it needs 2-3 slots) is not exactly cheap. Power consumption might then be en-par with the Pi.

          The RPi setup is LAN bandwidth limited though and not very 3D-capable depending on the setup…

        3. “Most people already have a PC” – well actually more people own laptops than desktop PCs, and of the PCs, many would not support multiple graphic cards. There’s also the processing involved in scaling a video across multiple cards over display port. So yeah, this is a good solution, and a lot cheaper than putting together a custom PC to do the same thing. Sure it can only play video, but then that’s often all that’s required for a video wall (I work in the event industry, using AV gear that costs 10′s of thousands of pounds to do essentially the same thing – although they do have failover and other nicities admittedly.)

  2. Nice work, but there are easier and cheaper ways to do this. I’m not sure what this setup would provide that couldn’t be done with a nice graphics card though.

    1. What cheaper way? What nice graphics card has nine HDMI outs and can support ~6k graphics.

      I think it is neat. It is just an addressed streaming service with a box to split the video up and push as required over a network. Simple, and more importantly means it would be easy to push video to remote locations. Want 20 video walls all running the same thing simultaneously at an expo center? No problem! Just assign multicast addresses and you still only need one control box.

      I don’t see how it could be any easier and cheaper without someone else making custom-rolled nine HDMI port with networking enabled hardware for 300 bucks. Since that does not yet exist, this project seems great!

      1. I think this illustrates the benefit of this build better than anyone else has. This is NETWORKED. I know people run their RasPis with PoE adpaters or custom PoE solutions, can you even imagine how amazing it would be to run TWO cables (or even three) Power for the TV, and PoE and Video coming in via ethernet. For 20 screens that’s ridiculous.

        A computer powered via a graphics card while more powerful, requires quite a bit of DVI as well as the full computer sitting close. Well, not close-by, but what ever.

        Maybe it’s worth the cost then, idk.

  3. This is pretty fucking sweet! I think the whole point of this is you can start as small as you want (which is damn cheap, don’t care what u say) and scale it up as you go along. Also in the past, I’ve had an absolute nightmare trying to get multiple monitors set up and to *stay* that way, battling with OS, drivers, etc.

    Also reading TFA it seems that you can designate custom aspect ratios, screen res, miss bits out (should you wish?) and hotplug. (didn’t say that but it certainly implied it). I don’t think this can be beaten for affordability. Show me a PC set-up where you can do ALL the above, scaleable & hassle free for cheaper and I’ll eat my pants before the gnomes get here.

  4. Waste of time/money for a horrible picture with monitor bevels..

    Projector.. One display.. one picture..

    AND it looks good.
    AND its far cheaper..

    I swear, people over engineering for substandard results.

    1. Projector has other requirements like a surface to project on, low ambient lighting, distance from projection surface, etc.

      And monitors have *bezels*, although bezels can have bevels…

  5. I don’t understand the negative comments above. This is a hack site to make one thing do another, not a ‘buy prebuild solution’ site.
    Give the guys credit for expanding the possibilities of something that was probably never intended to do this.

  6. 23″ displayport compatible monitor £125.00 x 9= £1125
    displayport compatible graphics card £95 x 3 = £285
    Asus Crosshair V Formula-Z AMD 990FX AM3+ Motherboard £186
    rest of PC £350 (minimum including software)
    Total £1946

    10 x Raspi £350
    23″ monitor as above £1125
    network switch £100
    total £1590

    Scalability for the raspi is far, far better as the Eyefinity technology is limited to 8192 x 8192 theoretically and most of the top end cards are limited to either 2560 x 1600 (GTX780 £558) or 4096 x 2160 (AMD7990 £530.00). There is no reason why the Raspi would have any limits to the resolution it could support

  7. First: you don’t need a Pi as master. Any Linux machine will do.
    Second: while checking your monitors for display port daisy-chaining, also check for: high current USB output. Pis need a steady 5 volts from a well regulated supply. If the TV can provide that you’re well on your way. Without it, there’s more power supplies and cables to add to the expense.
    Third: Speaking of expense, don’t forget an ethernet switch. Oh, and the instructions recommend a separate connection to any other existing LAN, so don’t try re-using your current LAN switch.

  8. Seems reasonable that the Pi’s should be able to do this. Saw a commercial solution that uses the same SoC as the Pi do this same trick quite nicely this last year at a trade show. From my experiences w/ my RPi, I’m a little surprised the Pi has the bus bandwidth for it, but it’s been a while since I’ve updated by RPi’s Linux distro.

    For all the naysayers who say you can use a specialized PC w/ a high end card, there’s the issue of physical space. Even mini-ITX PCs are huge compared to the RPi. The reason to use RPi’s or specialized digital signage boxes is that they are *tiny* and easily hidden behind a display or in the wall mount.

    For those who complain about the bezels, you just need more specialized screens: I remember seeing a Samsung display designed for just this purpose w/ almost *no* bezel (like 1cm, tops).

    And in the end all the naysayers miss the point: to have fun and learn something.

  9. thinking further about this most 22″ HDMI capable TVs also come with 1 or more USB sockets which would provide sufficient current/voltage to run the RasPi. This removes the need for the power supply so makes the wiring easier

  10. Hey there, I have recently connected 4-5 pico projectors to a single raspberry pi using usb display drivers. It worked fine, and I am using it in a super multi-view display project which is part of my PhD studies: http://www.youtube.com/watch?v=anle_AWp4nM

    I would be very interested in sharing how I did it. Because the usb display cards does not work out of the box with Raspberry PI. I will even soon write a description for it on my blog.

  11. Share please! :-)
    Did you by any chance use the separate outputs on the HDMI and some clever coding to pull this off?
    I had a similar idea for doing native 3D on an old notebook but using colour switching rather than on/off LCDs and RGB backlights to overcome flicker.
    Ran into an issue with a colour switching LCD that didn’t attenuate too much but found a workaround which is to use a different sort of panel.

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