OpenDMX Compatible Unbuffered USB-DMX Interface (part 2)

First prototype is coming in October, 2018.

UPDATE Oct. 20. Now it’s ready and it’s working. Tested with QLC+ and with three channel DMX receiver. It is however impractical large and heavy to connect directly in to USB port. So next version fixes this. Coming soon.

UPDATE Oct. 12. Almost ready.

Open DMX USB is an open USB to DMX hardware design developed by Enttec. The Open in Open DMX USB refers to the fact that everybody is free to use the design and produce its own USB DMX dongle without paying any licenses.

The Open DMX USB is inexpensive way to get into the world of controlling DMX devices from a PC. It relies on the computer for all calculations and timing of the DMX signal. It is ideal for small live music and theater applications.

Powered by a computer over USB. Standard 3pin DMX port. Compatible with a wide range of 3rd Party software. Control up to 512 channels. Plugged directly on to the USB port.

This DMX USB interface is based on the FTDI 232RL chip, it’s a USB to serial converter. It’s designed accordingly to the USB specification and will enter suspend mode when there is no activity on the bus. It then shutdown the device and draw no more than rated suspend current.

Using a simple application on a PC you can send and receive DMX512. Recommended application is QLC+ because it is a free and cross-platform software to control DMX or analog lighting systems like moving heads, dimmers, scanners etc. QLC+ runs on Windows, MacOS and Linux.

D2XX drivers. https://www.ftdichip.com/Drivers/D2XX.htm

List of compatible control software and programming examples. https://www.enttec.com/products/controls/usb/open-dmx-usb/

Reference schematics for DMX bus termination. http://www.mathertel.de/Arduino/DMXShield.aspx

DMX 3pin XLR pinout reference. https://en.wikipedia.org/wiki/DMX512#XLR-3_pinout

Text sources: