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Revision to Hardware Overview


[title|Hardware Overview]
[summary]Overview of Duet hardware[/summary]
== Hardware Details ==
For wiring and pinout of the board, see [|Duet WiFi and Ethernet wiring diagrams].
== Microcontroller ==
The Duet family of boards are based on the 32-bit ARM microcontroller [|SAM4E8E]. This is a microcontroller from the same family as that used in the (now-retired) [|Arduino Due]. Its general abilities are:
CPU family: Cortex M4
Clock speed: 120 MHz
Flash space: 512 kb
RAM size: 128 kb
Operating voltage: 3.3 V
Floating-point: hardware
The Duet WiFi additionally has a WiFi module, the [|ESP8266]. This is another 32-bit microcontroller with its own flash storage area, which is where the static files for the web interface are stored. It runs its own firmware, which occasionally needs to be updated. The Duet Ethernet has a W5500 TCP IP processor on board which handles the low level Ethernet networking functions. Installation of both the Wifi and Ethernet modules on the same board at the same time is not supported.
== Connectivity ==
The boards all support connection to a computer over USB, using any standard 3D printer host control program. The Duet WiFi can also connect to a secure WiFi network, while the Duet Ethernet, Duet 0.8.5 and 0.6 have an Ethernet port. The primary way to control these boards is with a web interface controlled through the network. Although they have removable on-board SD cards, the network interfaces provide fast enough file transfer that it is generally preferable never to remove the on-board SD card.
The boards also support a colour touchscreen called the [|PanelDue].
See also:
* [|Getting connected to the Duet WiFi]
* [|Getting connected to the Duet Ethernet or Duet 0.8.5]
* [|Connecting an LCD control panel]
== Power distribution ==
The Duet boards run on two basic power circuits. The digital electronics are supplied by a 5V circuit, which is internally converted down to the 3.3V levels that drive the MCU. This circuit also drives all the LEDs and sensors, and can be configured to feed the fans. The high-power devices, specifically the stepper motors and the heaters, are powered by a higher voltage, typically 12 or 24 V. This 12/24V circuit can be switched on and off through the PS_ON pin, if the power supply supports this (it may be a good idea to add such support through a relay, for safety reasons, if it doesn't) without interfering with the MCU at all. Alternatively, the Duet boards can draw power from this circuit to power the 5V circuit.
See also:
* [|Mounting and cooling the board]
* [|Power wiring]
== Motion ==
The Duet WiFi can drive 5 independent stepper motors. It uses Trinamic TMC2660 stepper drivers, which in addition to the standard step/direction/enable interface provide additional functionality (for example digital current selection and interpolation between microsteps) through SPI. If these chips become damaged or if users wish to use different drivers (for example supporting higher currents) then 5 additional channels of step/direction/enable pins are available on the expansion connector. With the onboard stepper drivers, it is possible to connect multiple motors in series; a connector is provided to make this convenient for the Z axis.
The Duet WiFi provides connectors for one endstop for each axis; these can be simple microswitches (normally open or normally closed) or they can be more complicated boards (for example optical switches) so long as they run off 3.3 V and can provide a digital (on/off) output. Additional endstop pins are available on the expansion connector. Any of these [|endstop] pins can also be configured to trigger user-defined actions, for example as a filament-out sensor or emergency-stop button.
The Duet WiFi also provides a connector specifically for a Z probe. This supports simple switches, boards producing analog outputs (at 3.3 V levels) and boards providing analog outputs that require an on/off modulation signal.
See also:
* [|Choosing stepper motors]
* [|Connecting stepper motors]
* [|Connecting endstop switches]
* [|Connecting an Emergency Stop button]
* [|Connecting and configuring filament-out sensors]
== Heating ==
The Duet WiFi supports power distribution to and control of three heaters: a heated bed (assumed to be the highest current draw with a maximum of 18A) and two extruder heaters. These are fed from the 12/24V circuit, but the PWM switching is carried out by MOSFETs on the ground, so if necessary they can be run off different voltages. Very high power bed heaters should probably be supplied independently and switched with a SSR.
Alongside each heater there is a temperature sensor input. These can be connected directly to thermistors (whose properties are set in the printer configuration files) or via expansion boards to PT100 sensors or thermocouples.
The Duet WiFi also provides connectors for several fans, some always-on and some PWM-controlled. These can be supplied with 12/24V or with 5V, or (since again the switching is by MOSFETs on the ground line) if necessary from user-supplied power inputs.
See also:
* [|Connecting thermistors]
* [|Connecting thermocouples]
* [|Connecting PT100 temperature sensors]
* [|Connecting a bed heater]
* [|Connecting and configuring a chamber heater]
* [|Connecting extruder heaters]
* [|Connecting fans]
== Expansion ==
The MCU driving the Duet boards has considerably more inputs and outputs than are used on the main board. Many additional lines are available on an expansion connector.
For the DuetWifi the [|Duex2 and Duex5 expansion boards] add 2 and 5 extra channels respectively.
For the Duet 0.6 and 0.8.5 the DueX4 provides 4 additional stepper drivers, [|endstop] connectors, heater outputs, and temperature inputs.
See the [|Duet WiFi and Ethernet wiring diagrams] for the expansion connector pinout.
== Electronics power consumption ==
When on external 5V power with no connected devices drawing power from the 3.3V or 5V supplies, both the Duet WiFi and Duet Ethernet draw about 200mA average from the 5V supply with the network interface enabled. For the Duet WiFi, the peak current when transmitting may be in excess of 300mA.
== LED indications ==
The board has a number of on board LEDs which are used to indicate the state of power, endstop switches, heaters etc:
== Version History ==
=== 2nd Generation Duets ===
The Duet Wifi and Duet Ethernet both use the same base controller board. the difference is only in the communications module. This base controller board has gone through a number of minor revisions. The version number is marked on the silkscreen on the board, to the left of the large processor chip.
=== v1.02 ===
Compared to v1.01 it had the following changes:
Changed to a Resettable VSSA. Now if the thermistor inputs are connected to VIN the VSSA fuse should reset rahter than needing to be replaced
Added capacitors on stepper driver outputs to reduce EMI
Added flyback diodes to the PWM fan outputs to protect against non brushless DC fans/pumps.
Minor routing changes
Source files: []
=== v1.01 ===
Compared to v1.0 it had the following changes:
Minor routing changes
Source files: []
=== v1.0 ===
The first production version. compared to the prototype it had the following changes:
ESP_COMMS Header breaks out all the spare ESP pins.
Added test points for Step,Dir and CS for the onboard stepper drivers.
Minor routing changes.
source files: []
=== prototype (v0.10) ===
This board is identifiable by the white solder-mask (all other boards are blue) it was made in a limited production run compared the version.
== 1st Generation Duets ==
=== Duet 0.8.5 ===
An updated and expanded version of the Duet 0.6, called the Duet 0.8.5 (multiple unreleased versions came in between) was released in Aug 2015. More details are available of the RepRap wiki here:
The source files are here
=== Duet 0.6 ===
The first duet released was version 0.6, developed by Think3dPrint3d and RepRapPro in 2013. More details are available on the RepRap Wiki:
The source files are here: