DMX RGB Holiday lights export E1.31 - Page 1
Forum section: electronics / projects

author: NivagSwerdna
author_rank: Super Contributor
timestamp: December 15, 2016, 08:50:31 pm
content: I'm too late for this year but for Christmas 2017 I'm thinking about having some computer controlled RGB strings...I know nothing about this DMX stuff but it looks like there are commercial products that support protocols such as E1.31?Does anyone know of any OSHW related to controlling RGB strings that exports E1.31 or similar via physical Ethernet or WiFi-ed?I would like something to start my design from and don't like re-inventing wheels unless they are proprietary.Thanks(and Merry Christmas and a Happy New Year)

author: ajb
author_rank: Super Contributor
timestamp: December 16, 2016, 01:36:11 am
content: Vanilla DMX is dead simple to implement on the receiving side--wait for a framing error, check the first byte you receive to ensure it has the proper start code, then start catching bytes. Transmission is slightly more complicated since the break/mark signals require microsecond timing if you want to maintain the maximum possible refresh rate. Adding RDM, which involves half-duplex communication, is of course a fair bit more involved, but probably not useful for a home holiday display in any case.Anyway, if you need <=512 8-bit channels per cable with minimal fuss, DMX is a good way to go. There are also lots of cheap/open source off-the-self hardware and software options both for control and for fixtures. It uses RS485 signalling, which is pretty tolerant of interference and shoddy wiring, and the standard actually permits the use of Cat-5 cable to carry two universes (though there's no reason you couldn't fit three for a total of 1536 channels).I don't know of any OSHW ACN implementations, the relatively few ethernet-based lighting control projects I've seen have used Artnet. Last year I came across an ESP8266 project that receives Artnet and was meant to control strings of SPI addressable LEDs. I adapted it to spit out DMX and control some existing DMX fixtures I'd built previously, with Q Light Controller Plus running a pre-programmed sequence on a schedule. Worked pretty nicely, although the ESP8266s would occasionally stop receiving Artnet, and I never bothered to chase that bug down. Artnet is also more common among control software and existing professional equipment from what I've seen, for what that's worth.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: December 16, 2016, 11:50:58 am
content: Thanks. This sounds like a very fun project. I have ordered some light strings total 300 dual RGB LED and WS2811... I guess I'll prototype something just to get them flashing and take it from there. I know nothing about any of these protocols... need to do some reading. Maybe DMX is a waste of time for my small installation.... I will definitely google ArtNet.RegardsNivag

author: dmills
author_rank: Super Contributor
timestamp: December 16, 2016, 01:37:37 pm
content: Artnet is basically DMX encapsulated over UDP, it is simple and it works (You can ignore the remote display stuff aimed at 80 * 25 text mode displays).ACN is the worst example of 'second system effect' I have ever seen, the DMX spec is a 'read over breakfast, hardware in the morning, software in the afternoon, working that evening' affair, ACN not so much.Of them all DMX is the easiest thing to implement, especially if you are just running dimmable loads and not moving heads, artnet is close if your controller has ethernet.Regards, Dan.