Connecting a Fly-407ZG via SBC


The Fly-407ZG is an STM32F407ZGT6 based board.

Firmware File

Choose the correct corresponding firmware (firmware-stm32f4-sbc.bin) from here. Remember to rename it to firmware.bin. Put it in the root of a FAT32 formatted SD card.


Connecting a Single Board Computer, such as a raspberry pi 3B/3B+/4.

Prepare the Raspberry Pi

Follow the instructions detailed here.


  • 5 x 100R resistor
  • jumpers or other ways of connecting to the Fly-407ZG

Connecting the SBC to the Fly-407ZG

The pinout for the Fly-407ZG can be found here and the schematic for the Duet 3 for reference can be found here. The raspberry pi GPIO pinout can be found here.

The table below shows the pins required on the SBC and what they are connected to on the Fly-407ZG. Please ensure that your cables are no longer than 30cm although they should ideally be as short as possible.

SBC Pin Fly-407ZG Pin Resistor Value
23/BCM11/SPI0 Clk PB13 on EXP2 100R
21/BCM9/SPI0 Miso PB14 on EXP2 100R
19/BCM10/SPI0 Mosi PB15 on EXP2 100R
24/BCM8/SPIO CE0 PF11 on EXP2 100R
22/BCM25 PB2 on EXP2 100R
20/GND GND on EXP2 None

Don’t power the raspberry pi from the Fly-407ZG. Either us a 12/24v to 5v step down transformer or power the pi from the micro usb or usb-c port.

Prepare the SD Card

All the SD card on the Fly-407ZG needs is the board.txt file with the following contents.

//Config for Fly-407ZG
board = fly_f407zg
sbc.TfrReadyPin = B.2
sbc.csPin = F.11
heat.tempSensePins = { F.3, A.0, C.1, C.0, F.10, F.5, F.4 }

Smart Drivers

If using TMC5160 or TMC22XX drivers (where 22XX is either the TMC2208, TMC2209, TMC2225 or TMC2226), the following line must also be added to the board.txt file

stepper.numSmartDrivers = X

Where X is the number of drivers fitted in total.

TMC22XX UART Drivers

The drivers must be continuous and start at unit 0 (unless TMC5160 are also used, which case they must be installed after them). So, for the SKR board, if you have say 3 TMC2208s and 1 other driver, the 2208s must be in slots 0, 1, 2 and the remainiong driver in slot 3 or 4. You can use RRF to assign any of those slots to an axis/extruder.

TMC5160 SPI Drivers

The Fly-407ZG is the only STM32 board that can’t be used with 5160 drivers. This is due to them sharing the SPI pins used to also gain SBC support.

Sensorless Homing

To be able to use sensorless homing on this board, a jumper cable needs to be installed between the diag pin of the driver and an endstop input.
For more information about setting up sensorless homing, please read this.

Board.txt Location

Place the board.txt file in a directory called “sys” on the SD card and install the SD card in the Fly-407ZG.


Turn it all on and you should be good to go.

You can either navigate to duet3.local or find the IP address of the rasberry pi using your router. If you don’t have access to that, use something like Fing to scan your network.

Once you’ve connected to the raspberry pi through your router, start to customise your config.g file etc or upload the outputted zip file from the Configurator to the pi using the system tab of DWC.


Please report any disconnects on either the forum or discord.

Changing the SBC hostname

This is an optional step if you only have a single duet3 on your network. It is required if you have more than one SBC configured RRF setup (as each setup on a network needs a unique host name) or you just want to change the name from the default “duet3”.

The name of the printer is its hostname on the network, you will need to connect to the SBC over SSH in order to run the Raspberry Pi configuration utility and change the hostname.

  1. Connect via ssh
  2. At a command prompt type
    sudo raspi-config
  3. Select “System Options” -> Hostname-> “OK”-> and set the new printername/hostname.

  4. Select “Finish” and reboot.

Once up and running

You will need to PID tune your tools and your bed. Please be aware that bed tuning may take up to an hour and tool tuning normally takes around 15 minutes. If it takes longer, that is also fine as up to 30 cycles may be ran.

To tune the bed, run the following command, changing the temperature (the S value) if a different tuning temperature is required.

M303 H0 S60

To tune each tool, run the following command, changing the temperature (the S value) if a different tuning temperature is required. This proceedure will activate the part cooling fans during the final phase of the tuning process so their effect is taken into account. If your printer has more than one tool, make sure each one of them is tuned.

M303 T0 S220

Once the tuning is complete, either copy the M307 command into the heater definitions or send M500, ensuring you have M501 at the end of your config.g.
If the tuning fails at the end, carry on saving the values as in most cases the outputted values still work correctly.
If the values still result in a heater fault, please refer to this wiki page for information about how to adjust the values manually.