ws2811 vs 1809 ic

[bob ginn]

Seems like a no-brainer, but hey, I'm the noob here, so I'll ask anyway:

ws2811=10 nodes per meter

1809 ic=30 nodes per meter

1809 megatree=much "fuller" and "denser" display?

[Steve Gase]

The WS2811 strips are like the LOR CCRs...   The CCRs have 150 LEDs, but they have 3 LEDs a pixel for a total of 50 pixels -- and that means 150 channels.


WS2811:
In 1-Meter you will have 30-RGB LEDs...  3 LEDs are in a "pixel".  so...  a 1-Meter strip will have 10 pixels, each pixel controlling 3 LEDs.   The 30 LEDs in 1-Meter will use 10x3=30 channels.


TM1809:
In 1-Meter you will have 30-RGB LEDs...  1 LED is in a "pixel".  so...  a 1-Meter strip will have 30 pixels, each pixel controlling 1 LEDs.   The 30 LEDs in 1-Meter will use 30x3=90 channels.

[bob ginn]

OK, I thought:

2811 has 10 "nodes" per meter, 3 pixels per node for total of 30 pixels per meter

1809 has 30 "nodes" per meter, 3 pixels per node for total of 90 pixels per meter

that's where i'm confused, hence the question about density

[sean]

it can be confusing.

my definitions
node is a light made up of r,g,b leds.

1809 and 2811 both have 30 nodes per meter. their spacing is identical. the 2811 , i think, puts out more light.

now when you go to turn on these 150 nodes on a 5m strip

the 1809 has a chip with 9 outputs. each node (because it has RGB leds) needs 3 of these. so an 1809 chip can individually control 3 nodes.
1809 has 10 IC chips per meter

the 2811 12v, also has 10 ICs per meter. the difference is the ICs only have 3 outputs. So to save money the manufacture ties all the RED leds of 3 nodes together, the 3 BLUE leds together and the GREEN leds together. when we turn on the IC, 3 nodes will light up.
so although there 150 nodes on a 5m flex strip, we only can address them as nodes 1-50.

i have 20 1809's on my megatree .
my arches and candles are using the 12v 2811.

one other note:
the 12v ws2811 is the chea[est light of any flex strip you can buy. it is $6 / meter. The 1809 is %10.50 /meter.

[Steve Gase]

OK, I thought:

2811 has 10 "nodes" per meter, 3 pixels per node for total of 30 pixels per meter

1809 has 30 "nodes" per meter, 3 pixels per node for total of 90 pixels per meter

that's where i'm confused, hence the question about density

your terminology and mine are different --

when dealing with the plastic rectangle modules, I've heard them called "nodes".  the 5050 LEDs have 3 per node, and they also are treated as 1 pixel. 

anyway...  I use "pixel" to refer to a single controllable element.  Here is a picture that shows how I use my terminology...




[attachment deleted by admin]

[sean]

steve if pixel is the light element we control with the controller, what do you call the 3 lights that make up a pixel in the 2811?

i say that the 2811 has 50 pixels, 150 nodes.
the 1809 has 120 pixels and 120 nodes

what people see when they look at flex strips is the lights. if you stand a few feet away from a 1809 and ws2811, you cant tell them apart because the lights (nodes?) are the same per meter.

it would be nice if there was a consistent definition of the elements.

[Steve Gase]

The 2811 controls 3 parts, that I call LEDs.  For example, a 5050 LED part.  With the WS2811 IC, all three of the LEDs are wired to show the identical colors...  3 channels controlling 3 LEDs.

The 1809 controls 3 parts as well, that I also call LEDs.  (and again, they may be a 5050 LED part -- and that that part has 3 components that separately produce Red, Green and Blue).  Each of the three LEDs on the strip are wired to the same IC, but they have unique pins to each LED.   9 channels controlling 3 LEDs, and each LED has 3 colors.

Fasteddy produced a nice Deck...  It is available to registered members of the AusChristmasLighting forum:

http://auschristmaslighting.com/forums/index.php/topic,1889.msg15570.html#msg15570

Here is another nice wiki discussion on these topics:

http://auschristmaslighting.com/wiki/AusChristmasLighting_101

i say that the 2811 has 50 pixels, 150 nodes.
the 1809 has 120 pixels and 120 nodes

I think your statement is a little misleading...
in the first example you talk about 150 nodes and I think you are talking about the 5-meter strip.
in the second example you talk about 120 pixels, and the 4 meter strip.

there is some confusion introduced because of the DLA limits.  RJ originally measured the power draw on the TM1809 strips and felt that the power over cat5 should only be allowed to power 120 of these LED parts, and so he limited the node count to 120... (yes, RJ uses "node" in his software labeling... but he uses "pixel" in other places )    To accommodate, Ray Wu sells those strips in 4M lengths.

If you use the ws2811 strips, Ray does not enforce RJ's 4M length because RJ originally did not support the WS2811 strips.  So Ray picked the commonly-available 5M length.

Why is this important?  Because the WS2811 5M strip is providing 150 LEDs -- and that would exceed RJ's intended 120 LED limit... but the WS2811 only allows those to be accessible as 50 pixels (or nodes in RJ's terminology).  So, using WS2811 with DLA allows you to exceed the approved power-over-cat5 limit.  50 pixels and 150 LEDs is more than RJ would suggest as acceptable.  Heck, you could connect WS2811 strips together  to have 120 pixels -- 360 LEDs and RJ's imposed limits would work -- you might blow a fuse, but the programming would allow 12M of WS2811 flex per SSC.  If you wanted to do this, use power injection!!

I agree, common terminology would help.  There have been folks working in this space for quite some time, and many have become set in their ways, so it might be difficult to change it now.