On 03/12/16 21:39, Tim Watts wrote:

http://www.sandevices.com/E681info.html

It's actually quite cost effective if you are driving a boat load and
can run cables out from a single location for a group.

But I still like the Pi idea...

I looked at that - and it seems to use something called DMX over
Ethernet aka E1.31 aka ArtNet(?).

I can find no meaningful examples of how to talk ArtNet(etc), except for
a very complete protocol definition (it is royalty free) - so that meant
dozens of pages of a very complex looking protocol. Without a clear
simple example, it's hard to know how easy/hard in practise it would be.

All the videos seem to be:

1) How to wire up pixel strings;

2) How to wire up E1.31 bridge.

3) Stick a Pi on it.

???

5) Profit!

If *I* were doing this, I think I would stick to my Pi idea - it would
probably be easier to invent your own simple text protocol, rather than
try to understand and drive E1.31! It looks very clever and very
suitable for full on theatrics (and efficient in its use of multicast).

I suppose it depends on how well timed your sequences need to be - if
you are running 10 strings in chaser mode, that must be 100% lockstep,
E1.31 looks like it is well designed for this. It might be harder to get
that sort of synchronisation over WIFI via a few Pi controllers.