The Duet is a 3D Printer controller board that is compatible with the Arduino Due. This 3D Printer controller combines the Arduino Due microcontroller with 4 stepper motor controllers, Ethernet, Hi-Speed SD card slot and more.
The Duet runs the 32 bit, ARM core SAM3X8E microprocessor, as found on the Arduino Due. This is a step change from preceding controllers using 8 bit microprocessors and leaves loads of overhead to do cool things (like running a webserver or running delta bots much faster). The Duet comes with Ethernet built in allowing it to run as a network printer controller, along with USB and an SD card (fully SD 2.0 compliant). In addition it takes the Duex4 expansion board for a further 4 stepper channels - for a total of 8 axis controls (3 axis + 5 extruders for example). A more in-depth description can be found in this blog post. The PanelDue is a compatible colour graphics touch screen control panel.
The wiring for the Duet and Duex4 expansion board is as shown:
Minor changes have been made to the Duex4 resulting in version 0.2a, as detailed in this blog post: link Duex4 v02a minor updates
The Duet hardware design is licensed under the CERN OHW License 1.2: the design is free to be distributed and modified within the terms of this license. All the design files are available on Github. The Duet was completely designed using the Open Source software package KiCAD so hacking and building on this design is accessible to all.
The Duet runs RepRap Firmware, a new C++ firmware by Adrian Bowyer. The software supports receiving GCode from over the USB serial port, from the SD card and from the ethernet interface. Additionally, the firmware can be uploaded using software packaged with the Arduino IDE or Eclipse (see below).
RepRapPro have released a video showing the web interface in use with the Ormerod printer. Forum user dc42 has published a series of blog posts showing how to use the Duet to control a Mini Kossel printer.
The software is adding new features daily, for example support for multiple extruder printing - see the T3P3 github, RepRapFirmware, multi extruder branch. The dc42 fork includes Delta and CoreXY printer support - see https://github.com/dc42/RepRapFirmware/tree/dev.
The Think3dPrint3d blog has a post on how to setup Eclipse to modify and compile the firmware with printer specific options, the ultimate aim to to have all printer specific options set by g-code.
Where to get it
Here is a picture of a 4 colour print from the Duet and Duex4 expansion board combo, and a picture of the set-up:
Known issues applicable to revision 0.6 boards
1. USB connector soldering: The Mini USB A/B connector has 4 metal lugs that need to be soldered to secure the connector to the board. Manufacturers of Duet boards sometimes don't get this right, probably because through-hole components are typically wave-soldered from the underside, but the USB connector lugs really need to be soldered from the top. Therefore, when you receive a Duet, check that the USB connector lugs are securely soldered from the top.
2. On-board 5V switching regulator: this produces too much EMI to meet CE regulations in a typical complete printer. If the EMI produced by the switching regulator is unacceptable, leave it disabled (by leaving JP9 open) and provide 5V power via the external 5V connector instead.
3. SD card: the board and firmware are a little fussy in respect of the SD card specifications. A Class 10 card with a capacity of around 4Gb is recommended, although good Class 4 cards will work too.
RepRapPro guide for commissioning Duet-based printers, including updating firmware: https://reprappro.com/documentation/commissioning-introduction/commissioning-duet/. You may also find their wiring diagrams for the Ormerod, Huxley and Mendel useful.
Gcodes: http://reprap.org/wiki/G-code (there is a table showing which firmwares support which gcodes, and this is kept up to date for the Duet/RepRapFirmware).
Preconfigured config.g files for various printers: https://github.com/reprappro/RepRapFirmware/tree/test/SD-image and https://github.com/dc42/RepRapFirmware/tree/dev/SD-image
Short guide to using dc42 firmware fork: https://github.com/dc42/RepRapFirmware/blob/dev/Notes%20on%20dc42%20fork%20of%20RepRapFirmware.pdf
Wiring and commissioning a Duet on a delta: https://miscsolutions.wordpress.com/2015/01/04/upgrading-the-mini-kossel-to-duet-electronics-part-1-hardware/
Official RepRapPro firmware binaries: https://github.com/reprappro/RepRapFirmware/tree/master/Release
dc42's fork firmware binaries: https://github.com/dc42/RepRapFirmware/tree/dev/Release
zombiepantslol's fork firmware binaries: https://github.com/zombiepantslol/RepRapFirmware/tree/dev/Release
zombiepantslol's DuetWebControl web interface (works with dc42 fork and zombiepantstlol fork of RepRapFirmware): https://github.com/zombiepantslol/DuetWebControl
PanelDue to Duet wiring: https://miscsolutions.wordpress.com/paneldue/