Interested in making one of these and have a few Qs please

Hi Com!

Thought I would try to help answer some of your questions to get you started. There is a lot more involved, but hopefully this will help get you pointed in the right direction. Also, I suffer from a complete inability to write short responses, so bear with me as this will be long...

Cost:
This varies greatly; size of your TV, type of LEDs you want, what equipment you already own, etc. For me, my initial build cost me probably $300 - $350 Canadian, which is about 175 - 200 GBP. that said, I had to buy things like wire, solder & soldering iron, a multimeter, and so forth. If you own some of this stuff already, you cost will obviously be less.

Brightness:
I'll be honest in that I don't remember 100% as I've recently moved and my setup is in pieces, but I'm pretty sure you can adjust brightness in the Hyperion software - apologies if I'm mistaken.

Input Lag:
Nope! I'm a huge gamer myself and there is no input lag. the signal is either dual output from HDMI on a supporting AVR or split off from a single HDMI source but in either case, the processing occurs separately, not in between the source and display so you should not experience any gaming related input lag. I've had no issues with this myself at all.

Raspberry Pi:
The type of Pi you use can matter, but between a Pi3 and a Pi Zero, either one works. I'm using a Pi Zero W myself. The OS you choose to run on it may create some difference in how you need to configure things, but that's at your discretion, not a function of the hardware. Many people use Openelec, I personally used Raspian Lite but both are fine (and there are others).

What is a hardware consideration are the connections you'll need to make. I used a Pi Zero W as I mentioned, which came without the pin header soldered on - I found it much easier to connect my wiring to the Pi this way. I also own a Pi 2 and I Pi 3, which both came with the pin header already soldered to the board (I'm pretty sure you can get them with or without the header pre-soldered, you just have to look). This isn't a problem per se, but you may wish to give that some thought in terms of what you're most comfortable with when making that purchase.

LEDs:
Not equal. There are many to choose from, and I would suggest there's a degree of subjectivity here but the top two options in my opinion are the APA102 and the WS2812B. I think the APA102 are considered the better overall product, and I would agree with that having used both, but that's primarily form an ease-of-use perspective and again, that's for you to decide based on the following and any additional research for you personal scenario:

- APA102 cost more, sometimes twice as much depending on your options for purchase.
- APA102 use SPI protocol so they can be driven directly from the Pi (though you may need a level shifter - worry about this later)
- WS2812B are not SPI, so you'll typically need to add an Arduino to drive the LEDs (I've seen some threads, even in this forum, that there might be workarounds fo this, but I'm not familiar with them - happy to be corrected if I'm wrong)

Basically, APA102 cost more but can be much easier to work with depending on your comfort/skill level. WS2812B are often much cheaper, but usually more involved in setting them up - If you know what you're doing, this is potentially a non-issue though. I was a complete "newb" and went with the APA102 which gave me no trouble.

lastly, you'll also need to consider how many LEDs per meter you want, irrespective of which LED type you decided to use.

Grabber:
The USB grabber that you want uses the UTV007 (often called Fushicai) chipset. The only way they are "problematic" (in my experience anyway) is that sometimes when you buy from amazon third party sellers or eBay/aliexpress however, what the listing says for the chipset, and what you get aren't always a perfect match, thankfully they're pretty inexpensive.

Off/On:
Turning off the LEDs can be done in the software anytime, but there are some other solutions as well. The solutions I've seen are a bit beyond my present skill level, so I won't advise on them, but there is some great info available on this forum and generally online. Personally, I would turn my LEDs off in Hyperion and then also unplug the power anytime I wasn't using them or wasn't home for added peace of mind.

I'll stop here for now but hopefully this is helpful - Good luck!

Happy to help!

If you're less interested in the DIY aspect, then the insanelight product looks pretty decent. I'm basing this just off what I see on the website (using google translate) having no experience with it, but it seems pretty good. The only other "plug n play" system I knew of was dream screen and while it works well to my knowledge, it uses very few LEDs which was the turn off for me personally. The insanelight appears to use 30/m APA102 which is really good (it says 32/m but I've only seen APA102 in 30, 60 or 144/m). If you decide to build your own however, I highly recommend using 60/m of whatever LED you choose.

Personally I love the mod. I'm actually soon to rebuild it having recently moved, but I find it very immersive. As I mentioned, I'm a huge gamer so the effect of having light shooting off screen is great. It makes explosions and things like that have more of an impact as they occupy more visual space by "splashing" off screen - again this is all personal opinion, but yes, I think it's worth it.

In terms of spacing, it will still work and 30 cm isn't too far, it's actually a very good distance I would say. Mine was about 6 - 10cm off the wall and looked great, but the light didn't spread out as far as I would have liked (pic below). Basically the farther away, the softer the light and the more the colours will blend but also the wider it will reach (to a point of course). I think the best course of action is to look up a bunch of YouTube videos and see what people's setups look like. There are many out there built on desktop PCs that are easily 30cm or more away from walls so you should be able to get a good idea of how it might look.

The main difference between 30 and 60 LED per meter is really a matter of "detail", when you have more LEDs you get a more accurate representation of what's on screen. Either looks good, but 60/m typically looks better. The way Hyperion works (in a very basic sense just for this example) is that each LED is tied to a sample area of the screen and then displays the "average" of the colour in that area. The fewer LEDs you have, the larger the sample area so you get more of a blending of colours. All that to say, if you do have a TV far from the wall, the light, and therefore colours, are going to blend anyway so your mileage will vary based on your personal setup.

Here are a few more photos for you. The first one is a test build I did on my PC using WS2812B and Arduino Nano and Prismatik software, it is at least 30cm from the wall (probably much more though) so you can get a sense of the effect at a larger distance. The rest are from my main TV build (APA102, 60/m, rPi 0 W, Hyperion).

Cheers!