How to Read Mainboard and Toolboard IDs

Power Off Before Proceeding

Before starting, completely shut down the printer and disconnect the power supply. Do not plug or unplug cables, rearrange wiring, or touch terminals while the system is powered on.

Notes

• Mainboard USB ID: Used to search for mainboards connected to the FLY-Lite2 via USB that have been flashed with USB firmware.
• CANBus UUID: Used to search for CAN toolboards connected to the FLY-Lite2 can0 network.
• Both the USB ID and CANBus UUID are searched via SSH over the network, not through the web-based DEVICES feature.

• Obtaining Mainboard USB ID
• Obtaining CANBus UUID

Obtaining the Mainboard USB ID

Important Notes

Power Off Before Operation

When connecting or re-plugging the mainboard USB cable, please completely shut down the printer and disconnect the power supply first. Do not plug or unplug the cable while the printer is powered on.

Scope of Use

• You must log in to the host machine via SSH to execute the search commands.
• Before proceeding, please confirm that the mainboard has been flashed with USB firmware and is connected to the host machine's USB port via a Type-C data cable.
• This tutorial is only for searching the mainboard USB ID and is not applicable for searching toolhead board IDs.
• For toolhead board devices, please refer to the USB or CAN ID acquisition tutorial in the corresponding product documentation.

Procedure

Searching for the USB Device ID

Log in to the host machine via SSH and run the following command to list all USB serial device IDs:

ls /dev/serial/by-id/*

Unusable IDs

After executing the command, please avoid using the following two types of IDs:

ID Characteristic	Reason	Example
usb-1a86_USB_Serial-if00-port0	Default name for generic serial chips like CH340; cannot be used as the Klipper mainboard connection address	/dev/serial/by-id/usb-1a86_USB_Serial-if00-port0
Contains katapult	The device is in Katapult flashing mode; Klipper firmware needs to be flashed first	/dev/serial/by-id/usb-katapult_xxxxxxxxxxxx

Search Results

Under normal circumstances, the terminal will display a device path similar to the image below. The ID in the image serves only as a format example.

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No Available ID Found: Refer to the Firmware and Connection Troubleshooting Guide

Multiple IDs Detected

If the command returns multiple available IDs, please identify the complete device path corresponding to your mainboard by checking the MCU model and comparing the device list before and after plugging/unplugging.

Filling the USB ID into the Configuration

Open printer.cfg in Fluidd or Mainsail:

Fluidd: Click the {…} icon on the left, then open printer.cfg. Loading...

Mainsail: Click "Machine" on the left, then open printer.cfg. Loading...

Use the Actual Search Result for the ID

All device paths in this document are examples. The USB ID of each mainboard may differ. Please copy the exact path returned by the SSH command.

Locate the [mcu] configuration section and change the serial parameter to the complete device path you obtained:

[mcu]
serial: /dev/serial/by-id/usb-Klipper_xxxxxxxxxxxx

When using USB firmware, you should configure serial. Do not fill in canbus_uuid in the same [mcu] section simultaneously.

Refer to the image below for the configuration location:

Fluidd Configuration Example Loading...

Mainsail Configuration Example Loading...

After modification, click SAVE & RESTART in the top right corner to save the configuration and restart Klipper.

CAN Connection Preparation

The FLY-Lite2 does not have an onboard CAN interface. Before searching, you need to connect a finished USB-to-CAN module and complete the can0 network configuration.

CANBus UUID Acquisition

Preparation

Important Prerequisites

• Toolboard Status: Ensure the toolboard has been flashed with Klipper-can firmware or is in Katapult-can mode
• Important Note: This tutorial is only for searching toolboard IDs, not for mainboard IDs
• Connection Requirement: The toolboard must be connected to one of the following devices:
  • UTOC module
  • A mainboard flashed with USB Bridge CAN firmware
• Final Connection: The above devices need to be connected to the host machine

CAN Network Configuration Requirements

• Default Configuration: This tutorial assumes the host machine has already configured the CAN network
• Fly Users: If using a Fly host running the Fly-FAST system, CAN is configured by default (1Mbps rate)
• First-time Use: Please be sure to read the tutorial below first: CAN Configuration Tutorial

Connecting via SSH

• Log in to SSH over the network (do not use serial login)
• Ensure the host machine is properly connected to the CAN network devices

Searching for CAN ID

• Search command for standard host machines

  ~/klippy-env/bin/python ~/klipper/scripts/canbus_query.py can0

• Search command for FLY host machines

  python3 ~/klipper/scripts/canbus_query.py can0

Explanation of Search Results

CANID

• Note: The mainboard ID has already been configured into Klipper in previous documentation, so the mainboard's CANID cannot normally be found during a search
• Quick Verification Method: If confirmation is needed, first disconnect the CAN connection cable between the mainboard and the toolboard, then re-run the search

• After executing the search command, the following situations may occur:

Result Displayed	Status Description	Next Steps
Application: Klipper	Device has Klipper firmware flashed	The ID can be used directly
Application: CANBOOT or Katapult	Device is in Bootloader mode	Klipper firmware must be flashed before use
Total 0 uuids found	No devices found	Please check the following issues: 1. Whether the CAN network configuration is correct 2. Whether the CAN baud rate is consistent (default 1Mbps) 3. Whether this ID is already in use in the configuration (if so, comment it out, save, power off, and restart)

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Regarding Duplicate IDs

If a device ID is already configured in printer.cfg, it will not appear in the search results. To search again, please:

1. Comment out that device ID in the configuration file
2. Save the configuration and restart Klipper
3. Power off and restart all devices

Configuring the CAN Device ID

1. Locate the Configuration File

Based on the web interface being used, find the printer.cfg configuration file:

Fluidd Click the {...} icon in the left navigation bar, then find printer.cfg Loading...

Mainsail Click Machine in the top navigation bar, then find printer.cfg Loading...

2. Add Device Configuration

Add the toolboard configuration to printer.cfg:

[mcu toolboard]
canbus_uuid: <fill in the queried ID here>

Configuration Notes

• toolboard is the name of the toolboard; modify it according to the actual situation
• For a mainboard ID, the configuration section should be [mcu]
• In normal configurations, the mainboard uses [mcu], and the toolboard uses [mcu toolboard]

3. Save and Restart

1. Click the SAVE & RESTART button in the top right corner
2. The system will automatically save the configuration and restart Klipper

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Note

All IDs appearing in this documentation are examples only; the actual IDs differ from board to board. Please modify and fill in the ID based on what you actually obtain.