Support for the WS2811 pixel controller.

[Timon]

I was just wondering if the SSC might get an alternate firmware load to support the WS2811 pixel chip? The protocol differences between the  WS2811 and the TM1804 are minimal, the data stream format are the same just the bit cell timings are a little different. Heck, these two chips are even pinned out the same they are so close to each other.

This chip has several advantages over the TM1804. First it's a constant current chip so voltage drop in the pixel cable won't effect it as much as the TM1804. Second, there are many more variations in available pixel types than the TM1804. Lastly the pricing of WS2811 pixels are generally quite a bit less that the TM1804.

Each chip has it's place but considering how little the code would need to be modified it seems to me that supporting the WS2811 would be a very good idea.

Just my two cents and IMHO.

John

[rm357]

Buzz. No.

1. The 2811 is a 5 volt part. SSC is 12. To regulate down at the SSC would require a big heat sink. To send 5v from the hub would require too many modifications.
2. Only supporting one type of node is already confusing enough for our less technical members.

Buzz. The 1804 series chip is also constant current. The light decrease over a 128 node string is not that significant when viewed from 30 ft. If we restrict ourselves to 50 nodes/string like the 5 volt strings, the decrease is less than the 5 volt parts and we don't have issues if the power dips a little like the 5 volt parts. The 2811 may or may not have better current regulation, but nobody does serious led dimming any other way. They just use the buzzword in their documentation.

[rm357]

I'll apologize in advance if the previous post seems harsh, but really, how many times is this question going to be asked. A new thread every week??

[dpitts]

The 2811 also comes in a 12v version.

[tbone321]

While this sounds great, the real issue is confusion.  It is already getting bad with 3 current firmwares for the SSC.  If you add this protocol, now you will have 6.  This also means that if there is a new feature added to the SSC, then at least 4 firmwares will need to be updated and tested.  The whole idea is to keep it s simple as possible and sometimes that requires a little sacrifice in the number of options. 

[charles59]

Why does it have to a new firmware?  Couldn't the SSC setup utility make that an option, the pixel type?  The pic on the SSC would seem to have enough flash to handle outputting several different pixel formats.

[RJ]

Guys as has been clearly stated before, I will not be adding different protocols. If the chip that is inside matters that much to you then you likely are advanced enough that endless options are avaliable to you already.

RJ

[tbone321]

That depends on the structure of the firmware and that I do not know.  The main core of the firmware woud have to be changed to allow it to select the desired output routine, The output routine(s) would need to be rewritten as calls so that different ones could be selected.  The bootup routine of the firmware would have to be changed to allow it to load and understand the output routine selection, and the config software would need to be changed to both give the selection of the pixel type desired and to write the output somewhere in flash RAM whee it an be read.  Then all of these change would need to be tested.  This is not a simple thing and there really isn't enough time to do it, at least not this year.  Then there is the issue of well if you now allow this chip then why not that one.  As always, what is done and not done with the SSC is completely up to RJ but with the amount of work currently on his plate, even of he really wanted to do this I really don't see how he would find the time.

[Timon]

Since it seems that the WS2811/12/12B is now a supported part with the existing code which is great.

[combustionmark]

Since it seems that the WS2811/12/12B is now a supported part with the existing code which is great.

Not exactly supported, WS2811 just happen to work with the existing code. The existing code is for TM1804 and may not always work.

The WS2812 and WS2812b are 5 volt and will require power injection.

Using WS 2811 will require some additional investigation "voltage and speed"

There are several that have been tested by others that have worked, and some that do not.