I am wanting a completely wired solution for both DMX and SPI on a rPi. I will do the SPI directly off the gpio. How can I get the dmx?
usb dongle and Ola?
at this point, i have no preference. It all has to be hardwired, and I have to be able to use SPI and DMX, I was hopeful to do everything from GPIO, but dont know if this is possible.
If you’re dedicating a single Pi to this, then I guess you could use the GPio for SPi and a USB dongle for DMX, but be aware that both need VERY precise timings for them to work correctly.
You’ve then got the issue that you’d need an Art-NET / sACN to GPio / SPi and USB DMX server to accept the streams from openHAB2.
OLA might be an option, but I couldn’t get my head around it.
Personally, I’d look at 2 dedicated Art-NET / sACN to SPi or DMX adapters, that could be connected to a separate LAN adapter on your openHAB2 machine.
That way the Art-NET / sACN adapters will take care of all the DMX and SPi timing issue.
Even if you run them on your home LAN and the odd data packet gets delayed, your lights will still retain the state assigned by the last good packet.
There are lots of reasonably priced Art-NET adapters out there.
I like these by SmartShow.
Single universe of DMX over Art-NET or sACN
A universe of Art-NET / sACN to each SPi output.
A pair of universes of Art-NET / sACN to two SPi streams. ( 170 RGB or 127 RGBW pixels to each SPi stream )
Alternatively, you could use a LAN device that serves out 6 universes of DMX, then hang a DMX to SPi adapter on an output?
I have used these from Electron Design.
With these DMX to SPi adapters
Or Yuri has combination adapters that can output 3 channels of 5 amps of PWM dimming, with an SPi output.
(The first 3 channels are shared between the RGB and SPi stream, subsequent DMX channels are used in the SPi stream)
These can be found in his eBay shop along with lots of other great devices.
Bob at SmartShow and Yury at Electron Design have always looked after me when I’ve bought things from them.
If it helps, my pixel count will quite low; probably somewhere around 30 to 40 at the most. It will actually go into a vehicle…
So in effect, you’re using less than 1 full universe of DMX then.
My advice would be…
Grab yourself a NetDMX from SmartShow to get a good solid DMX stream out of openHAB2, then buy a couple of Yuri’s DMX to SPi PCBs and effectively turn your SPi pixels into DMX fixtures.
If you’re in the UK, I’m happy to help you more directly.
I appreciate the direction…I’m in the US.
Sorry that the US is just a little too far for me to “pop round” and lend a hand.
One tip, if you do get yourself a NetDMX from Bob, keep in mind that you can only initiate access to the admin web interface or Serial port during the first 8 seconds.
(There is a really good reason for this, which I’m sure you can appreciate)
Please do post some pictures or video of whatever you’re creating
I’d go for a ethernet -> dmx gateway. There are several low cost diy solutions.
That’s what the NetDMX is, but can you put any links up for other devices, as I’m always interested in alternatives.
Yes, please do…I will post some pics of a quartz countertop I underlit, as well as this project one complete.
I am using three of the Art-Net-Boxes (50€).