The DuetWifi is a 3D Printer controller board that is based on the high powered ARM core Atmel SAM4E8E. It integrates 5 TMC2660 stepper motor drivers, Wifi, Hi-Speed SD card slot, PT100 and thermocouple daughterboards and more.
The Duet runs the 32 bit, ARM core Atmel SAM4E8E microprocessor, as a upgrade on the SAM3X8E used on previous Duet boards. This more powerful processor integrates and FPU allowing for fast kinematic transforms for Delta and CoreXY printer geometries along with a wide range of peripherals such as a high speed, SD 2.0 compliant SD card an SD card. The stepper drivers allow for up to 256 microstepping, along with 16 microstepping with interpolation up to 256 this allows for very fast step rates and incredibly smooth, quiet motion. An expansion header allows for 5 further stepper drivers, 5 further heater channels and more to be added.
The user interface is the powerful and easy to use [Duet Web Control] which runs in a web browser, along the user interface to work on PC tablet or phone. In additon the PanelDue, a colour graphics touch screen control panel, can be connected for direct control.
See the Duet3d wiki for more detailed information on wiring
All connectors are Molex KK type, with lock and polarization.
Board is built with four layers, including a complete ground plane, which allow good thermal dissipation and reduce noise and ground loops.
Biggest thermal dissipation came from the bottom of the board, so cooling from below is most effective.
Processor voltage is 3.3V and inputs are not 5V compatible, so using sensor with higher voltage needs reliable protection.
- Maximum acceptable voltage in is 25V.
- The TMC2660s Stepper drivers will reach 2.8A with stand still current reduction. currently they are firmware limited to 2A and run comfortably with no heatsinking at this current, see the thermal test results for more information. Drivers have a thermal safety and provide the firmware with additional information about thermal state, motor stall and correct motor connection over SPI.
- Stepper driver current is adjusted by firmware, using a specific G-code.
- Microstepping is variable between 1 to 1/256. High step rates, combined with smooth and quiet motion can be achieved by using 1/16 microstepping with interpolation to 256 microsteps on the driver.
- On board 5v is supplied by a buck converter with ultimate current of 2A. This supplies the 3.3V rail, and expansion boards especially the PanelDue.
- Micro-SD card type SDHC, to be formatted in FAT32, cluster size 32 kB.
- Wifi transfer rates from 300 kB/sec to 1000 kB/sec depending SD card quality, file size and wifi network quality.
- Direct connection of mechanical switches to endstop inputs is reliable with shielded or twisted cables.
Size 123 x 100mm, hole spacing 115 x 92mm Micro-SD slot, mini USB plug, wifi antenna, the majority of indicator LEDS, reset and erase buttons are on one small side, allowing for mounting with just this edge exposed. There is no plug for power supply, but a terminal block on the side opposed to plugs. 5V could be from internal converter or external supply, with pins aside the power supply terminal block. The board contains circuity to control a compatible power supply (such as an ATC PC power supply)
The export from KiCAD shows the board and hole dimensions:
With more info on the wiki
Drive number for G-Code commands (M569 & others) 0:X; 1:Y; 2:Z; 3:E0; 4:E1; 5:E2; 6:E3; 7:E4; 8:E5 9:E6
These can be remapped to allow for example X, Y and Z to be on drive number 5,6,7 on the expansion header for easily using large external drivers.
The Wifi connection is handled by the onboard Wifi Module, which connects via high speed SPI to the main processor. The Wifi module runs the Web server, offloading the main processor. Gcode and firmware can be uploaded via wifi, firmware can be updated OTA. In addition once a print has started the browser can disconnecr form the printer and then reconnect at a later time.
Open hardware license
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, initiated by Adrian Bowyer, which was initially designed for it It has now been rewritten and expanded by David Crocker (DC42 on the forums). The software can receive G-Code from the USB serial port, the SD card and the Ethernet interface.
Its philosophy is everything is done with G-code, including all configuration and it use an extended set of G-codes.
Configuration file is read on SD card at start-up. Interactive configuration with immediate feedback is possible.
A pre-compiled version of the firmware is supplied with each new release. Average user never have to compile the program and does not need any development tool.
SD image shall be copied on SD-card and macros may be adapted for a given configuration. Firmware updates can be copied over Wifi, USB or though directly writing to the SD card. the firmware updates can be triggered via WIFI, USB or PaneDue. See Duet_Firmware_Update for more information
When Duet board is connected via Wifi, any network device having access to your network can operate the printer with a web interface.
The software is evolving constantly. The dc42 and ChrisHamm forks includes Delta and CoreXY printer support.
Where to get it
- Duet3d (UK) The collabroation between Think3dprint3d and Esher 3d. DuetWifi, IR probe, PanelDue with scree, PT100 and Thermocouple daughterboards.
- Filastruder (USA) Duet 0.8.5, Duex4 & PanelDue with screen 4.3"
- builda3dprinter.eu (The Netherlands) Duet Wifi and PanelDue with screen.
- Escher 3D (UK) PanelDue without screen
- General support: https://www.duet3d.com/forum/
- RepRap Firmware FAQ
- RepRap Firmware G-Codes
- RepRapFirmware Configuration & commissioning