The Duex2 and Duex5 are expansion boards for the Duet WiFi. They are not compatible with the Duet 0.6 or 0.8.5.

In the following instructions given for the Duex5 apply equally to the Duex2 except where noted..

Features ¶ 

The Duex2 and Duex5 are based on the same PCB with 3 channels of steppers, heaters fans etc not populated on the Duex 2 to save costs.

Duex5 ¶ 

• 5 additional TMC2660 stepper motor drivers with stall notification.
• 5 additional extruder heater outputs.
• 5 servo outputs with 5V power and 5V signal levels, sharing control channels with the heaters. So you can use unused heater channels to drive servos.
• 5 additional endstop inputs with indicator LEDs and 3.3V/5V voltage selection. These are also usable as outputs.
• 6 additional PWM controlled fan outputs*, also usable for driving LEDs etc. The output voltage may be switched between 5V, 12V and VIN .
• 4 uncommitted general purpose I/O pins.
• 12V 2A switching regulator, for generating a 12V supply for fans, LEDs etc. when the VIN power is higher than 12V.
• 5 additional thermistor inputs.
• Support for 2 more thermocouple or PT100 daughter boards, supporting up to 4 more sensors.
• Optional 5V external power input for powering servos, fans etc.

Duex2 v0.8a and newer ¶ 

• 2 additional TMC2660 stepper motor drivers with stall notification.
• 5 additional extruder heater outputs.
• 5 servo outputs with 5V power and 5V signal levels, sharing control channels with the heaters. So you can use unused heater channels to drive servos.
• 5 additional endstop inputs with indicator LEDs and 3.3V/5V voltage selection. These are also usable as outputs.
• 6 additional PWM controlled fan outputs, also usable for driving LEDs etc. The output voltage may be switched between 5V, 12V and VIN .
• 4 uncommitted general purpose I/O pins.

*12V switching regulator, for generating a 12V supply for fans, LEDs etc. when the VIN power is higher than 12V.

• 5 additional thermistor inputs.
• Support for 2 more thermocouple or PT100 daughter boards, supporting up to 4 more sensors.
• Optional 5V external power input for powering servos, fans etc.

Duex2 v0.8 and older ¶ 

• 2 additional TMC2660 stepper motor drivers with stall notification.
• 2 additional extruder heater outputs.
• 2 servo outputs with 5V power and 5V signal levels, sharing control channels with the heaters. So you can use unused heater channels to drive servos.
• 2 additional endstop inputs with indicator LEDs and 3.3V/5V voltage selection. These are also usable as outputs.
• 6 additional PWM controlled fan outputs*, also usable for driving LEDs etc. The output voltage may be switched between 5V, 12V and VIN .
• 4 uncommitted general purpose I/O pins.
• 12V switching regulator, for generating a 12V supply for fans, LEDs etc. when the VIN power is higher than 12V.
• 2 additional thermistor inputs.
• Support for 2 more thermocouple or PT100 daughter boards, supporting up to 4 more sensors.
• Optional 5V external power input for powering servos, fans etc.

Note version 0.6 and 0.7 had 5 additional PWM fan outputs, 6 additional fan outputs are available from version 0.8 onwards

Mounting and Cooling ¶ 

The Duex5/2 is designed to be mounted back-to-back with the Duet WiFi using long M4 screws and spacers. Alternatively, it can be mounted adjacent to the Duet WiFi with the expansion connectors on the two boards next to each other.

It is also possible to mount the two boards side-by side with power connectors next to each other, but in this case the 50-way ribbon cable needs to be at least 200mm long instead of the standard 100mm.

As with the Duet WiFi, the stepper motor drivers are cooled via the PCB. To improve cooling, you can use a fan to blow air over the PCB, especially the underside. When the Duet WiFi and Duex5 are mounted back to back, you can use a single fan to blow air between the two boards.

Wiring ¶ 

Duex2 and Duex5 wiring diagram

• Use the 50-pin ribbon cable supplied with the Duex5 to connect the two expansion connectors together. Important! The cables must be oriented as shown in the diagram. If you have a white pre-production Duet WiFi then the 50-way expansion connector is probably fitted the wrong way round, with the keyway on the side next to the edge of the board (wrong!) instead of away from the edge (correct). To fit the cable, you will need to file down or cut off the protruding key on the cable end.
• Connect VIN and GND terminals of the Duex5 to the corresponding terminals of the Duet WiFi. Do not run separate ground wires from each terminal block back to the power supply unless the power supply is very close (less than 100mm) to the Duet WiFi and DueX5. Instead, run a very short and thick ground wire directly from the negative (-) terminal of th VIN terminal block on the DueX board to the negative VIN terminal of the Duet. Also connect the negative wire from your power supply to the negative VIN terminal of the Duet. You can run separate +VIN wires from the Duet and DueX5 back to the positive terminal of the power supply if you wish.
• Caution! On early production (v0.6, v0.7) DueX2 and DueX5 boards, the VIN and GND markings on the underside of the board are incorrect and should be swapped over, so GND is the terminal that is also marked -, and VIN is the terminal that is also marked +.
• Important! You must have a reliable low-resistance connection between the negative (ground) terminals of the two VIN terminal blocks. Failure to do so may result in high currents flowing in the ground connectors of the ribbon cable and may cause damage to the Duet WiFi or Duex5. Preferably, make this connection using either solid core wire, or stranded core wire with ferrules of the correct size crimped on securely. Re-tighten the terminal block screws regularly for the first few days of use, to make sure there is no creep in the wires causing the screws to become loose.
• Important! If you have previously used the Duet with Duex4 expansion board, note that the VIN terminal block polarity of the Duex5 is not the same as on the Duex4. Instead, the + and - terminals line up between the two boards when the Duet WiFi and Duex5 are positioned back-to-back or side-by-side.
• You do not need to connect anything to the 5V_EXT_POWER connector unless you want to supply external 5V power to power servos and fans.
• As with the Duet WiFi, you must never connect or disconnect anything (except the USB connector) when the board is powered up. In particular, connecting or disconnecting stepper motors while powered may damage the stepper driver chips.

Jumpers ¶ 

• Place the fan voltage select jumper in the 5V, 12V or VIN position according to your needs
• Place the endstop voltage selection jumper in the 5V or 3.3V position according to your needs
• Place the 5V_SELECT jumper in the INT position, unless you want to provide 5V power to servos and fans from the external 5V input
• If you will be using VIN power greater than 12V and you wish to enable the on-board 12V converter, put a jumper across the 12V_EN PINS

Commissioning ¶ 

The DuexX5 is supported in firmware 1.16 and later. You must upgrade your firmware if you are using an earlier version.

• Double check your wiring, in particular the polarity and security of the connections to theVIN terminal block. The DuexX5 is not protected against reverse supply voltage polarity.
• Apply 5V power only, for example via the USB port on the Duet WiFi.
• Connect to the Duet WiFi via Duet Web Control, or using a USB host program such as Pronterface.
• If using DWC, go to the Gcode Console page
• Send command M115. Check that the ELECTRONICS string reports "Duet WiFi + Duex5" or "Duet WiFi + Duex2" as appropriate. If the "Duex5" part is missing, remove power and check your wiring.
• If you have connected additional thermistors, thermocouples or PT100 sensors, send appropriate GCode commands to enable them and test that they are giving the correct readings.
• If everything is working so far, apply 12V or 24V power and proceed with testing other devices you have connected.