Introduction
The Duet 3 Mini 5+ balances value and performance, focused on small and medium size machines that do not need the high power output of the Duet 3 Mainboard 6HC. It provides 5 on board drivers and the normal complement of heaters, fans, IO, LCD etc. There are Wifi and Ethernet variants, with the option of using an SBC (Single Board Computer, e.g. Raspberry Pi) for control in the same manner as other Duet 3 mainboards. It has a header for a two driver expansion board and a CAN-FD port for connecting Duet 3 expansion and tool boards.
Except where otherwise stated, the following applies to both the WiFi and Ethernet versions.
Features
The main hardware features of the Duet 3 Mini 5+ are listed below.
| HARDWARE SPECIFICATION | ||
|---|---|---|
| Duet 3 Mini 5+ WiFi | Duet 3 Mini 5+ Ethernet | |
| Processor | ATSAME54P20A | |
| Processor features | 120MHz ARM Cortex M4F, 1Mb flash, 256Kb RAM, hardware floating point (single precision), DMA, 4Kb cache | |
| Networking/Comms | 2.4GHz WiFi; USB port; serial port | 10BaseT/100BaseTX Ethernet; USB port; serial port. |
| On-board stepper drivers | 5 x TMC2209 | |
| Stepper driver features | Up to 2.0A peak current (TBC), microstep interpolation from any setting to x256, stall detection, stealthChop2 | |
| Heater outputs | Bed heater (up to 18A TBC), 2 x extruder heater (up to 5A each) | |
| Thermistor/PT1000 inputs | 3, optimised for 100K thermistors and PT1000 sensors | |
| Fan outputs | 4 controlled fans of which 2 support 4-wire fans with PWM and tacho wires, voltage selectable between VIN and 12V in 2 banks | |
| Inputs/Outputs | 5 on-board I/O connectors plus 2 input-only connectors for endstop, filament monitor, Z probe, servo or PanelDue connection. Inputs are 30V-tolerant. Further expansion via CAN-connected expansion boards. | |
| Endstop or filament monitor inputs | See under Inputs/Outputs | |
| Z probe connector | See under Inputs/Outputs | |
| Power monitoring | VIN voltage monitoring allows for state save on power failure. | |
| SD card interface | On-board high speed (22.5Mbytes/sec) SD card socket. | |
| EXPANSION | ||
| Support for attached Raspberry Pi or other Single Board Computer (SBC) | Yes | |
| External stepper driver support | 2 external stepper drivers from stepper driver expansion connector. Multiple expansion via the CAN bus including 1XD external driver boards. | |
| Stepper driver expansion | 2 additional TMC2209 stepper drivers using a mini 2+, further expansion via CAN | |
| Heater/thermistor expansion | Expansion via CAN using 3HC or toolboard 1XD. | |
| PT100 and thermocouple daughter board support | 1 board (2 channels) | |
| Servo support | See under Inputs/Outputs. Also one output with 5V signal level for servo, laser or VFD converter (shared control signal with one of the 2-wire fan outputs). | |
| LCD support | PanelDue colour touch screen, mini 12864 mono graphics display using ST7567 controller (3.3V signal levels) | |
| LED strip support | RGB Neopixel (max. 60 LEDs, external 5V power required) | |
| Other expansion | Via I/O ports and CAN bus | |
Firmware notes
- Compatible RepRapFirmware versions: RRF 3.2 and later
For firmware update instructions, see Duet 3 Mini 5+ firmware page. If running from an SBC, see Update Duet 3 connected to SBC.
Operating limits
| Stepper drivers | Up to 2.0A peak current (TBC) |
|---|---|
| Heater outputs | Bed heater up to 18A (TBC), 2 x extruder heater up to 5A each |
| Input power voltage | 11V to 25V |
| Inputs/Outputs | Inputs are 30V-tolerant |
| Fuses | 10A for V_FUSED, 15A for OUT0 (e.g. for a heated bed). |
| 5V current limit | 1.0A total on 5V and 3.3v, including the internal current consumption (around 200-300mA), any PanelDue or other display, and any endstops/Z probes that draw significant power. |
| 12V current limit | 800mA (only used for fan outputs OUT_3 thru OUT_6, when selected) |
Wiring
The wiring diagram page also includes a description of each connection.
Physical properties
Dimensions
Mounting
The form factor of the Duet 3 Mini 5+ is the same as the Duet Maestro and can be mounted in much the same way, though the driver connectors are flipped sides compared to the Maestro.
Cooling
In many applications passive cooling will be sufficient, especially if the board is mounted vertically in a well ventilated position. If active cooling is needed then a fan blowing across the back of the board along the line of the stepper drivers is recommended.
The stepper drivers' heatsinks are connected to the PCB and the majority of the heat is dissipated via the PCB so heatsinks on the stepper driver chips are largely ineffective.
MCU Temp
Unfortunately the SAME54P20A chip used in the Duet 3 Mini does not have a functioning temperature sensor. In theory it does have an on-chip temperature sensor, but the errata document for the chip says it doesn't work.
Stepper Driver Temp
Due to this you would be unable to monitor the MCU temp in order to control fans. The driver sensors do work for fan control, but only return flags of warning and overtemp,
3D Model
Note some people have reported issues with using windows build in unzip program to extract these files. please try 7Zip or similar if you have this problem
Connectivity
IO port pin capabilities
OUT0 to OUT6 are all PWM-capable. OUT6 is shared with LASER/VFD.
| IO # | UART? | Analog in? | PWM out? | Notes |
|---|---|---|---|---|
| 0 | yes | no | no | Can be used to connect a PanelDue |
| 1 | yes | no | yes | |
| 2 | yes | no | yes | The standard firmware does not support this UART |
| 3 | no | yes | yes | Shared with backlight control on 12864 displays having Neopixel backlights |
| 4 | no | no | no | IO4_OUT is shared with PSON output |
| 5 | no | no | n/a | 3-pin connector, input only |
| 6 | no | no | n/a | 3-pin connector, input only |
Feature Comparison
See the Duet family of motion control electronics page for a feature comparison table between different versions of the Duet.
Revision History
Revision 0.5
- Add 5V TVS diode footprint option so either 1610 or SMC can be used on 5V.
- Move OUT3 and OUT 4 connector up slightly to clear the stepper diver expansion header.
- Added pullup between Driver enable and 3.3.V
- Add 3.3V TVS diode
- Updated the 12V and 5V BUCK input circuits to improve EMC performance.
- Updated the passive components around the Ethernet Phy to improve EMC performance.
- Further minor routing and component updates.
Revision 0.4
- Added CAN support
- Removed IO_4 (pins used for CAN) and renamed IO_5, 6,7 to 4,5,6.
- Remove 1 stepper driver and TMC diag mux. Used freed pins to route each stepper driver diag line directly to the MCU. Significantly improves stall detection performance.
- Swap 4 wire fan pin headers for normal molex KK
- 3 way jumper to choose between External 5V and 5V_SBC
- Swap the pinout for IO6 and IO7 to be the same as Duet 2
- Rename DIAG LED to STATUS
- Further minor routing and component updates.
Revision 0.2
First prototype, this revision will not be supported in future firmware releases.
Revision 0.2 IO port pin capabilities
| IO # | UART? | Analog in? | PWM out? | Notes |
|---|---|---|---|---|
| 0 | yes | no | no | Can be used to connect a PanelDue |
| 1 | yes | no | yes | |
| 2 | yes | no | no | The standard firmware does not support this UART |
| 3 | no | yes | yes | |
| 4 | no | no | yes | |
| 5 | no | no | no | IO5_OUT is shared with PSON output |
| 6 | no | no | n/a | 3-pin connector, input only |
| 7 | no | no | n/a | 3-pin connector, input only |
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