Homebrew USB DMX Interface with Sparkfun FT232RL(openschemes.com)
openschemes.com
Homebrew USB DMX Interface with Sparkfun FT232RL
https://openschemes.com/homebrew-usb-dmx-interface-with-sparkfun/
6 comments
This existing design perfectly fine for a DMX transmitter. Unlike receivers, DMX-512 transmitters are not isolated. The isolation required in receivers will protect the transmitter from the condition you described.
EIA-485 specifies the electrical properties of the signal, however the ESTA E1.11 (DMX-512) specification further constrains it in section 5 and 6 in regards to grounding and isolation.
Annex A of the specification does provide allowance for non-isolated transmitters where common-mode voltage is expected, but this is specifically not recommended:
https://tsp.esta.org/tsp/documents/docs/ANSI-ESTA_E1-11_2008...
EIA-485 specifies the electrical properties of the signal, however the ESTA E1.11 (DMX-512) specification further constrains it in section 5 and 6 in regards to grounding and isolation.
Annex A of the specification does provide allowance for non-isolated transmitters where common-mode voltage is expected, but this is specifically not recommended:
https://tsp.esta.org/tsp/documents/docs/ANSI-ESTA_E1-11_2008...
You'd be surprised what kind of terrible things can happen on a run of DMX cable. I've seen enough transceivers exploded out of their sockets to be wary. The leading US manufacturer of lighting controls continues to use socketed DIP rs-485 transceivers exactly because they tend to take hits and fail.
I wonder what is "RS-488" mentioned in the article. I can't find anything about that.
I suspect that his is a typo and it's the well-known RS-485, because SN75176 is a RS-485 interface chip.
I suspect that his is a typo and it's the well-known RS-485, because SN75176 is a RS-485 interface chip.
I think it's a typo. The DMX protocol is subset of Rs-485
Maybe they were thinking of IEEE-488?
tangent and pretty specific, but does someone know if there is something like a diy version of Enttec's dmxis? (that is, something like a midi to dmx converter)
I didn't know about DMXIS and tried to look it up, and it seems that there is a software and a hardware component (the latter not being produced anymore), see here:
https://www.dmxis.com/dmxis/
I don't know about the software, but as for a DIY hardware solution, you can just connect a USB-DMX interface (like the Enttec DMX USB Pro) and a USB-MIDI device to a laptop and "just" have to code something to translate MIDI input to DMX output. Or use an Arduino, an RS-485 module and a few other components, that's what I once did.
https://www.dmxis.com/dmxis/
I don't know about the software, but as for a DIY hardware solution, you can just connect a USB-DMX interface (like the Enttec DMX USB Pro) and a USB-MIDI device to a laptop and "just" have to code something to translate MIDI input to DMX output. Or use an Arduino, an RS-485 module and a few other components, that's what I once did.
Ah yes I should've been more specific - the DMXIS box from Enttec is a small piece of hardware which takes MIDI input and has an output port for DMX fixtures. Accompanied by a software to create mappings from one to the other. Would be a fun project to design and code this but I was wondering if there is anything similar out there already :)
Is there something like Freestyler for Linux?
I’ve used QLC+ in the past which worked well
I suspect this homebrew interface will work with QLC+ with no software mods necessary if you set the right settings. It already supports some commercial products that use the same FTDI chip:
https://www.qlcplus.org/docs/html_en_EN/dmxusbplugin.html
https://www.qlcplus.org/docs/html_en_EN/dmxusbplugin.html
I used to use DMXControl on Windows for stage play FX lighting (on-stage things such as uplighters, fireplaces, illuminated signs etc.) and would just setup a presets board with virtual push buttons.
I had a quick skim through the QLC+ site but couldn't see whether it had an equivalent feature. Any thoughts? Thanks.
I had a quick skim through the QLC+ site but couldn't see whether it had an equivalent feature. Any thoughts? Thanks.
I assume we aren't talking about Earl Simmons, so WTF is a DMX, and why would I want to interface with one?
DMX in this instance stands for "Digital Multiplex" and is mostly shorthand for "DMX-512" which is a RS-485 like protocol for controlling (usually theatrical) lighting systems.
Its for things like this:
https://www.youtube.com/watch?v=S5D7SYiA6w4 Daft Punk - Around The World (Official Music Video with Audio Commentary by Michel Gondry)
https://www.youtube.com/watch?v=vemkhYYb16w Daft Punk - Around The World (Official Music Video Making Of)
https://www.youtube.com/watch?v=S5D7SYiA6w4 Daft Punk - Around The World (Official Music Video with Audio Commentary by Michel Gondry)
https://www.youtube.com/watch?v=vemkhYYb16w Daft Punk - Around The World (Official Music Video Making Of)
https://www.analog.com/en/analog-dialogue/articles/isolated-...
A homebrew interface like this may be ok for learning, but if you plan to get income from running a light show use an isolated interface or you will be liable if anyone gets hurt.