CAN Firmware Compilation

Pre-Flash Notes

Confirm Current Mode and Operation Path

• Important Note: If the toolboard is already in Klipper-CAN mode, you can directly flash it via command after compiling the firmware. The command will automatically reset it into Katapult and complete the flash.
• Factory State: The board comes pre-flashed with Katapult firmware in CAN mode at a baud rate of 1M.
• Status Check (via LED): If the onboard LED is blinking (as shown below), it indicates the board is in Katapult mode and ready for flashing.
  Loading...
• Abnormal Mode: If the LED does not blink, the firmware is not Katapult. You must reflash it by following the link below: Click here to flash Katapult firmware

Setting DIP Switches and Physical Connection

1. DIP Switch Settings: Regardless of the current state, first set the onboard DIP switch to CAN mode and turn on the 120Ω switch (as shown below).

   Loading...

2. Device Connection: Use a CAN cable to connect the toolboard to a UTOC or a mainboard already flashed with bridge firmware. Refer to the diagram below for wiring:

   Loading...

3. Critical Check (Termination Resistor): With the system completely powered off, use a multimeter to measure the resistance between the CAN_H and CAN_L pins.

   Device	Operation Instructions
   Toolboard	Locate and install the jumper cap marked 120Ω.
   Mainboard	If connecting to a mainboard, also install its 120Ω jumper cap.
   UTOC Module	Includes a built-in resistor.

   How to Check:

   1. Keep the system completely powered off.
   2. Use a multimeter to measure the resistance between CAN-H and CAN-L on the toolboard's CAN port.
   3. Result Analysis:
      • Approximately 60Ω: Normal, both termination resistors are correctly connected.
      • Approximately 140Ω: The CAN-H and CAN-L wires may be reversed.
      • Approximately 120Ω: The 120Ω resistor is not installed, or there is a break in the wiring.
      • Approximately 40Ω: There may be an extra resistor; please check the intermediate nodes.

---

Start Compilation

Brief Guide to Firmware Compilation

Notes

• Network: Ensure the host (Raspberry Pi, etc.) is connected to the internet.
• Login Method: Must log in via SSH over the network; serial port access is disabled.
• Input Method: Keep the keyboard in English half-width mode.

---

SSH Login and User Switching

Use tools like MobaXterm, PuTTY, etc., to SSH into the host.

Switch User:

• Standard System (Official Raspberry Pi system, etc.)
  Do not use root; switch to a regular user:

  su <username>

• FLY Host System (FlyOS-FAST system)
  Only supports login as root user (password: mellow)

---

Firmware Compilation Operation Guide

In the Klipper firmware configuration interface, only keyboard operations are supported; the mouse cannot be used.

Key	Function
↑ / ↓	Move cursor up/down to select menu items
Enter / Space	Confirm selection, check options, or enter submenus
ESC	Return to the previous menu
Q	Exit the configuration interface
Y	If prompted when exiting, press Y to save the configuration

Start Firmware Compilation

The following describes how to compile the firmware:

• After connecting via SSH, enter the following command and press Enter:

  cd ~/klipper && rm -rf ~/klipper/.config && rm -rf ~/klipper/out && make menuconfig

• Where rm -rf ~/klipper/.config && rm -rf ~/klipper/out is to delete previous compilation data and firmware

• make menuconfig is for compiling the firmware, after execution you should see the following interface

  Loading...

• Select Enable extra low-level configuration options and press Enter

  Loading...

• Enter the menu Micro-controller Architecture then select Raspberry Pi RP2040/RP235x and press Enter

  Loading...

• Select Bootloader offset, select:16KiB bootloader

  Loading...

• Select Communication interface, select:CAN bus

  Loading...

• Select (4) CAN RX gpio number, delete 4 and input 1

• Select (5) CAN TX gpio number, delete 5 and input 0

  Loading...

• Select GPIO pins to set at micro-controller startup, enter:

  !gpio5

  Caution

  Please input in English input mode

  !gpio5

  Loading...
  • Please check against the image above to ensure it matches, then proceed to the next step

• Press the Q key, Save configuration will appear, then press the Y key

Loading...

• The configuration should now be saved and you will return to the command line interface
• Enter the following command to start compiling, it will take some time

make -j4

Loading...

• The following output indicates successful compilation
• Due to Klipper version issues, only the appearance of out/klipper.bin indicates success

  Linking out/klipper.elf
  Creating bin file out/klipper.bin

Search ID and Flash

Querying CANBus UUID

Prerequisites

• It is recommended to perform ID query and firmware flashing operations in a non-printing state to avoid interfering with the printing process.
• The Katapult (CANBoot) firmware and Klipper firmware on the same mainboard/toolboard use the same CAN ID.

Prerequisites

Please ensure the following conditions are met, otherwise the CAN ID may not be found:

1. The host's CAN network is correctly configured
2. The toolboard's CAN baud rate is exactly the same as the host's (inconsistent baud rates will prevent communication)
3. Executing the lsusb command shows the 1d50:606f device (USB-CAN adapter)

Search Command (Choose based on system)

• Standard host search command

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

• FLY host search command

  python3 ~/klipper/scripts/canbus_query.py can0

Search Result Explanation

Case 1: Mainboard/Toolboard with Klipper Firmware Flashed

• Display: Shows one CAN ID, with the prompt Application: Klipper
• Explanation: The device is already running Klipper firmware and can be used directly. This ID could belong to the mainboard or the toolboard.
• Differentiation Method: Disconnect the toolboard's CAN cable and search again. If the ID disappears, it belongs to the toolboard; if the ID remains, it belongs to the mainboard.

Loading...

---

Case 2: Mainboard + Toolboard Ready for Flashing

• Display: Shows two CAN IDs
• Explanation: The mainboard runs Klipper firmware, and the toolboard runs CanBoot firmware, waiting to be flashed.

Loading...

---

Case 3: UTOC + Toolboard Ready for Flashing

• Display: The UTOC itself does not display an ID, only the toolboard's ID is shown
• Explanation: The UTOC acts only as a bridge; ensure the toolboard is in CanBoot mode.

Loading...

---

Case 4: No ID Displayed

• Display: No IDs are shown
• Possible Reasons:
  1. The CAN bus is occupied by Klipper
  2. Incorrect baud rate configuration on the host's CAN0 interface
  3. Physical wiring issues
  4. The device is not in CanBoot mode

Loading...

---

Important Notes

• Ready for Flashing State: When the toolboard is in CanBoot mode, it will display Application: CanBoot and the firmware LED will blink. Firmware flashing can be performed at this time.
• ID Occupancy Handling: If a device is already running Klipper firmware and the ID has been entered in the configuration file, the ID will not be shown (occupied by Klipper). To display it again, you need to comment out the ID in the configuration and perform a complete power cycle.

Troubleshooting

If you cannot query the UUID, please refer to: CAN Issue Troubleshooting Guide

Firmware Flashing

Flash Command

1. Replace 241696050c56 in the command below with the UUID you actually queried
2. Note: A space is required after the -u parameter

python3 ~/klipper/lib/canboot/flash_can.py -u 241696050c56

Confirming Successful Flash

A CAN Flash Success prompt indicates successful flashing:

Loading...

Firmware Update

Update Method

When a firmware update is required, simply:

1. Recompile the firmware
2. Ensure the device's CAN ID can be queried (or that Klipper is connected to the device)
3. Execute the same flashing command

python3 ~/klipper/lib/canboot/flash_can.py -u <MCU ID>

Update Success Example

Loading...

Confirm Firmware Startup

• If the firmware starts normally, the LED will light up.
  Loading...