Author Topic: Help getting started with pixels and E1.31  (Read 893 times)

Offline frankv

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Help getting started with pixels and E1.31
« on: October 24, 2017, 08:08:17 PM »
I've been running Xmas lights for several years, starting with a Renard 24-ch controller, and adding in some Wifi-controlled dumb LED strips via my own software. This year, I'm going to the next level with pixels, controlled via my variant of ESPixelSticks.

I have my first 300-pixel strip lighting up, controlled from my phone via the ESPixelStick's "Testing" web page. So far so good. Next step is to get FPP to talk to it. I have FPP running on a RPi, connected via Ethernet to my network router, which talks WiFi to the ESPixelSticks. But I'm unclear about how to proceed from here. As with all data comms, it's also a bit difficult to tell whether the problem is at one end or the other, or between my ears!

My understanding is that I go into FPP, and in the Input/Output Setup, tell it that the E1.31 interface is "eth0", and set up a universe. (I'm a bit unclear on what a "universe" is; I think that in my world it's all the pixels attached to one ESPixelStick). So I would set up Universe #1 to start at FPP Channel 1 and be size 300. After a bit of reading, I think I want it to be "Unicast", and I need to give it the IP address of my ESPixelstick. (Can I give it a DNS name instead? Or do I have to give fixed IPs to all my ESPixelSticks?)

I guess I also need to set the same things up on each ESPixelStick, so each would have the right Universe number and have channels 1-300?

From there, I should be able to go to FPP's "Display Testing"/"Channel Testing" p[/img]age, and run tests on the pixel strip?

And then, I use xlights/nutcracker to create sequences which turn on FPP channels. Lot's more learning for me here too, I think.

As an aside, I've seen comments around the place saying that show lights should be on a separate network from normal computing use. Why is that? Is it just a matter of not clogging up the links with show traffic? Or is there some kind of security issue? I have a spare WiFi router I can set up, but I think it's convenient for testing to be able to talk directly to the ESPixelstick from my phone.

Offline JonB256

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Re: Help getting started with pixels and E1.31
« Reply #1 on: October 25, 2017, 09:09:17 AM »
If you use a lot of WiFi for actual pixel data, not just for Multisync data from Master to Remote, then a separate network is needed.

If you use E1.31 Unicast over CAT5, then I don't think it is needed. An easy "add-in" to isolate data is to use an inexpensive Ethernet Switch to keep the data traffic out of your home network router. (I'd recommend getting an 8 port Gigabit switch, but that's just me)

The concept is that you run a single CAT5 line from your Router to that switch. Then EVERYTHING show related connects to that switch. The way the switch functions (versus an older hub) is that it actively directs Unicast traffic from source to destination only. If all your sources and destinations are plugged into that switch, no traffic of consequence goes upstream to the router, keeping the spouse and children happy.

I've run my show this way for three years now and it works. Plus, because you use a switch instead of a Router, everything can still have the same IP subnet as your home computers, so communication is easy (PC, tablets, smartphones, iPads).

Offline pixelpuppy

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Re: Help getting started with pixels and E1.31
« Reply #2 on: October 25, 2017, 09:49:35 AM »

An E1.31 Universe is a collection of [up to] 512 channels that are transmitted in a single IP packet.  It was originally developed for DMX-over-IP but is also used to transmit pixel data over IP.  Since each pixel uses 3 channels of data, a single E1.31 Universe can carry up to 170 full pixels of data (with 2 channels left over).   So, for 300 pixels you will need a minimum of 2 universes.  I believe the ESPixelStick can receive up to 4 universes (680 pixels) per stick.

300 pixels should not be bogging down any modern home network - wired or wireless; segmented or not.  300 pixels running a sequence with 50ms timing (20fps) will consume about 144Kbps of network bandwidth (300pixels x 24bits-per-pixel x 20frames-per-second=144Kbits-per-second).  That's K as in Kilo, not Megabits or Gigabits.  (disclaimer: there is some additional overhead data not included in this calculation but it is not significant for this order of magnitude)

Carry on with learning the sequencer and have fun playing with making the pixels do patterns.  You shouldn't need to worry about your network until you get into the thousands of pixels.
« Last Edit: October 25, 2017, 09:59:36 AM by pixelpuppy »
xLights and Vixen3 for sequencing / FPP for scheduling and playing / Falcon controllers for pixels / homemade controllers for everything else


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