How to configure an SBC for use with LPC based Boards

A Raspberry Pi 3/3+/4 is recommended (Raspberry Pi Zero and lower than a 3 (i.e. the original and 2b) are not supported).

Prepare the Raspberry Pi

DuetPi is the official Debian image based on Raspbian that is customised for the Duet 3. If you are not very familiar with the Raspberry Pi, it is strongly recommended to use it instead of the stock Raspbian image.

There are two versions of DuetPi available, one with and another one without GUI:

These versions are targeted at ARMv7 processors like the Raspberry Pi 3 or 4.

Once downloaded, use a flashing application like Win32DiskImager or baleanaEtcher. You can follow the official Raspberry Pi instructions for further details.

When the image of your choice has been flashed, the Duet 3 can be connected to via the hostname “duet3”. It comes preconfigured with mDNS enabled (via avahi), SSH activated (on the lite version only) and the standard credentials “pi” and “raspberry”. To set up WiFi, you can edit “wpa_supplicant.conf” on the SD card (first partition), see here for instructions.

If you want to enable SSH on the DuetPi with GUI image, SSH can be enabled by placing a file named ssh, without any extension, onto the boot partition of the SD card from another computer (this is only needed for the GUI version). When the Pi boots, it looks for the ssh file. If it is found, SSH is enabled and the file is deleted. The content of the file does not matter; it could contain text, or nothing at all.

Installing/Updating to the latest stable version

Regardless of whether you are installing the LPC specific DSF changes for the first time or are updating to the latest stable version, the procedure is the same. We suggest using the automatic mode.

To use the automatic updater, send the following:

sudo chmod 755

This does everything from the manual section.
Thats the SBC prepared and ready.

To use the automatic updater, send the following:

sudo chmod 755

This does everything from the manual section.

If the updates fail with an error exit status 1, run the following and then rerun the script.

sudo mv /var/lib/dpkg/info/duet* /tmp/
sudo mv /var/lib/dpkg/info/reprapfirmware.* /tmp/
sudo apt-get update
sudo dpkg --configure -a
sudo apt-get install --reinstall duetcontrolserver

As soon as your Raspberry Pi has established an internet connection, it is recommended to install the latest updates. To do so, connect via SSH (e.g. via PuTTY) to your Raspberry Pi or open a terminal and run

sudo apt update
sudo apt upgrade

This will install the latest software components and the latest RepRapFirmware version on your Duet 3.

Prepare the LPC version of DSF

Stop the duetcontrolserver and duetwebserver.

sudo systemctl stop duetcontrolserver
sudo systemctl stop duetwebserver

Then edit the config.json

sudo nano /opt/dsf/conf/config.json

Now change the following lines.

  • SpiBufferSize from 8192 to 3072
  • SpiTransferMode from 0 to 3
  • MaxCodeBufferSize from 356 to 200
  • MaxMessageLength from 4096 to 2560

Now restart duetcontrolserver and duetwebserver

sudo systemctl start duetcontrolserver
sudo systemctl start duetwebserver