I am not late to the party here, honest. I have been playing with these for some time, and even design and make LED controllers.
The ubiquitous protocol is "WS2812", which is basically a serial data stream on one data line at a rate of around 1MHz with short or long pulses being 0 and 1 as data, and a long gap being end of sequence. The exact timing in the various data sheets do seem to vary slightly. SK6812 is similar.
The data sequence is binary values, 8 bits per byte, and the bytes that are each colour. The exact colour order varies depending on chipset it seems (patent/copyright/god knows why). In general it is Green, Red, Blue, but can be Red, Green, Blue, and I have seen others.
Each device consumes its data sequence for its colours, and passing on the remaining stream. Once the long gap comes all devices load the accepted colours to their LEDs simultaneously, which is cool.
There are also RGBW, which have four bytes not three, so include a "white" level. This is cool (or warm) as the white LED is often larger, and brighter, and the power of one LED but white (doing white with R+G+B is not as nice a white, and uses 3 times the power).
Coding for this is simple, and ESP has ways to do it - typically using the "remote control" system for IR remotes, but can also be done using SPI bus with a little fun with the logic. This allows working with many devices as a serial stream via SPI is very simple.
They also get smarter with some designed to take a backup data which is a connection of the data in to the previous pixel. If the backup comes in without the expected data, it can accept the backup, one pixel later, as its own data, and pass on as such. As such a single dead module does not break the chain.
So, we have many choices, the exact chipset, the order of colours, if white included (which flavour of white such as cool, warm, natural, etc), if backup line, and voltage.
The voltage is a fun one - commonly 5V, the voltage drop over a long strip is too much and you lose blue, then green, so have to inject 5V at multiple points in some cases. But 12V has options - one is 12V drives three sets of RGB LEDs in a chain, so 3 "pixels" the same, but another is 12V works one "pixel" (the WS2815 range do this). I have, however, some that work on 3.3V (impressive for blue) for on board LEDs, and I use these all the time on my PCBs - they would not work on a "chain" of LEDs off the board.
What would be nice, and I am not sure I am quite seeing yet (please say if not), and seems the logical conclusion here would be.
- 12V supply (working all the way down to 5V or less)
- Per pixel control (not sets of 3 pixels together)
- Backup data line
- RGBW option so white on the pixel (in choice of colour temperature)
It looks like the last point is the sticking point from what I read, as WS2815 does the rest, but when finally common place, that will be the ideal solution. The 12V working allows long strips on single supply. The W allows lower power and brighter "white" as functional lighting. The per pixel control is obviously better. The backup is obviously prudent. It would be extra cool if it can run from 5V on the same chipset, just obviously suffering the voltage drop issues over a long run.
For extra fun, I tested the WS2815 (12V) modules and they work very happily from 5V, so allow a hell of a lot of voltage drop. The data sheets say +9~+13V
