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.

The main hardware features of the Duet 3 Mini 5+ are listed below.

• 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.

See: Duet 3 Mini 5plus Wiring

The wiring diagram page also includes a description of each connection.

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.

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.

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.

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,

• Duet 3 Mini 5+ Ethernet STEP file.
• Duet 3 Mini 5+ Wifi STEP file

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

OUT0 to OUT6 are all PWM-capable. OUT6 is shared with LASER/VFD.

Capabilities of IO_0 to IO_6 are shown below.

See the Duet family of motion control electronics page for a feature comparison table between different versions of the Duet.

• Added Jumpers to bypass 10K input protection resistors with 470R resistors for IO2.in and IO3.in. This is to allow these inputs to be used with I2C.
• Add a 10K pulldown resistor between signal line io4_out and ground. This is to prevent PS_ON turning on momentarily when the board is powered up.

• Component footprint and solder stencil changes to improve manufacturability
• Ground plane changes to further improve EMC performance
• Minor component changes to increase commonality with other Duet 3 products

• 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.

• 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.

First prototype, this revision will not be supported in future firmware releases.