8 replies to this topic

[derekbackus]

Hi all.

 

Does anyone have an example of the Netduino controlling a WS2811 LED strip? I've been looking for samples, but all I can find is references to FastSPI used with the Arduino but nothing for the Netduino.

 

Thanks, Derek

[Stefan]

Hi Dereck and welcome to the Netduino forums!

 

I haven't seen the WS2811 being used with a Netduino. The WS2801 works though, code can be found at http://netmftoolbox....are.RgbLedStrip

Not sure if it would work the same though.

[JerseyTechGuy]

I'm working on building a RBG illuminator for Paranormal Investigation and have looked at both the WS2801 and WS2811. I believe the WS2801 is being phased out and the 2811 is the replacement. The main difference is a 3wire interface vs 4wire. Cost is also a little less on the WS2811. I haven't gotten far enough to tell if the drivers are different as I'm still designing the prototype boards but what I've read they should be the same.

[derekbackus]

From what I've read, the timing is different (and critical) for the 2811. I've read here (http://doityourselfc...l-compatibility) that the 1804 and 2811 are compatible, but with timing differences.

 

I'm not advanced enough to know how to make it all work yet.

 

Thanks, Derek

[Nevyn]

Stefan,

 

Not sure if it would work the same though.

 

They are radically different.  There was a recent post on HackaDay about LEDs controlled with the WS2811.  You can find the write up here

 

Regards,

Mark

[charliewallace]

Question - is the OneWire library the solution?

 

I'd like to use a Netduino Plus 2 to control this 60-led-per-meter strip, that uses the WS2811: https://www.adafruit.com/products/1138, But the description says I can't use Netduino:  

 "...it will not work with the Raspberry Pi, Basic Stamp, NETduino, any other interpreted/virtual machine microprocessor..."

 

Tragic that Netduino fails to pass this test, given how much more powerful the cpu is compared to the AVR. 

 

I've read on this forum that the OneWire library didn't make it into the NETMF 4.2 release, but was included in some beta version of 4.1.  Could someone comment on whether this could be used to achieve the timing stability needed for this? 

 

Or - is it feasible to implement unmanaged code to send out the bits, and just mask interrupts for timing stability?  You need to send all the led data at once, but you don't need to refresh, so this would only hold off the managed code when the state changes.

 

I understand that the actual device being used is the WS2814[color=#ff0000;]2812[/color], which combines the leds with an embedded ws2811 in a single package.  Here's the data sheet:

  http://www.nooelec.c...iles/WS2812.pdf

 

thanks!

  Charlie

[Juzzer]

Well [color=rgb(40,40,40);font-family:helvetica, arial, sans-serif;] "...it will not work with the Raspberry Pi, Basic Stamp,[/color] NETduino[color=rgb(40,40,40);font-family:helvetica, arial, sans-serif;], any other interpreted/virtual machine microprocessor..." is wrong [/color]

 

http://www.ghielectr...share/entry/649

[kathy82]

[color=rgb(40,40,40);font-family:helvetica, arial, sans-serif;]On Netduino, the SPI itself is very fast, but the delay between one "Write" and another one is very long. So long that the natural delay itself could act as "start" for the ws2801 led strip. [/color]

[TinkeringTurtle]

On Netduino, the SPI itself is very fast, but the delay between one "Write" and another one is very long. So long that the natural delay itself could act as "start" for the ws2801 led strip.

 

In case someone runs across this thread, check out this tutorial to write your own low level write function to get around this...

 

https://learn.adafru...tduino/overview