FLY-ERCF Bootloader (Katapult) Recovery

For unbricking recovery only

FLY-ERCF is pre-flashed with Katapult at the factory. Do not repeatedly flash the firmware on this page during normal use and Klipper firmware updates; this page is only for unbricking recovery after the Bootloader is damaged.

Firmware Description

Name Description

Katapult was formerly named CanBoot; both may appear simultaneously in old tutorials or old firmware names.

Katapult is the bootloader used to boot and update Klipper:

• Katapult itself cannot be used as a Klipper MCU; after flashing, the Klipper firmware matching the hardware and communication method still needs to be written.
• The method for entering Katapult is subject to the current product page: boards with a RESET button can enter by quickly double-pressing RESET; boards with only a BOOT button require fully powering off first, then holding BOOT while connecting USB, and releasing it once the device is recognized. After entering, there is usually a status LED blinking.
• CAN, RS232, and USB use mutually independent Katapult firmware and cannot be mixed by simply changing the file name or using them directly.
• CAN firmware must also select the correct bus rate; common rates are 500K and 1M.

• The FLY-ERCF supports CAN and USB communication.
• The repository provides USB firmware, as well as CAN firmware for two speeds: 500K and 1M.

Select Only One Firmware

USB and CAN firmware cannot be used simultaneously. When selecting CAN firmware, the firmware speed must match the host and all CAN devices on the same bus.

Entering Bootloader Mode

Power Off First

Before starting, fully power off the printer and disconnect the power supply. Do not plug or unplug wiring harnesses, arrange interface cables, or touch terminals while the system is powered on.

The BOOT button is indicated in the figure:

1. Keep the toolboard completely powered off.
2. Press and hold the BOOT button.
3. Connect the toolboard to your computer or host using a Type-C cable that supports data transfer.
4. Release the BOOT button once the device is recognized.

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Flashing Firmware

• Windows
• Linux / FLYOS

1. Confirm that the device has entered UF2 flashing mode, and a removable disk named RPI-RP2 appears on the computer.

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2. Release the BOOT button or remove the BOOT jumper.

Windows file extension display

Windows may hide file extensions. Please check "File name extensions" in File Explorer, and confirm that you are using .uf2 firmware; do not modify the firmware extension.

3. Download the Flash erase firmware:

• nuke_universal.uf2

Windows 默认可能隐藏文件扩展名。下载后请确认文件扩展名未被修改，不要保存成 .txt 或其他扩展名。

The directory of the erase firmware in the repository is:

FLY-Firmware/RP2040

4. Copy nuke_universal.uf2 to the RPI-RP2 disk to erase the old firmware already present on the device.

5. After the copy is complete, the RPI-RP2 disk will automatically disappear; after the device erases the Flash, it will appear again as an RPI-RP2 USB drive, and at this point the Flash is already empty.

6. Download the FLY-ERCF Katapult firmware:

• FLY_ERCF_CANBOOT_USB.uf2
• FLY_ERCF_CANBOOT_500K.uf2
• FLY_ERCF_CANBOOT_1M.uf2

Windows 默认可能隐藏文件扩展名。下载后请确认文件扩展名未被修改，不要保存成 .txt 或其他扩展名。

The firmware directory in the repository is:

FLY-Firmware/ToolBoard/ERCF

7. Copy the Katapult .uf2 firmware to the newly appeared RPI-RP2 disk.

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8. After the firmware is written, the RPI-RP2 disk will automatically disappear, indicating that Katapult has been flashed successfully.

1. Compile the RP2040 flashing tool. Skip this step if it has already been executed.

cd ~/klipper/lib/rp2040_flash/
make

2. Confirm that the device has entered UF2 flashing mode.

lsusb

If 2e8a:0003 appears in the output, it indicates that the device has entered RP2040 flashing mode. The device name displayed may differ across systems; the USB ID should be used as the reference.

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Device not recognized

Do not continue flashing if 2e8a:0003 does not appear. Please disconnect the device power again and repeat the steps in "Entering flashing mode" on this page.

3. Pull or update the precompiled firmware repository.

• Linux
• FLYOS

First-time download:

cd ~
git clone https://cnb.cool/3dmellow/FLY-Firmware.git

Update the repository if it has already been downloaded:

git -C ~/FLY-Firmware pull --ff-only

First-time download:

git clone https://cnb.cool/3dmellow/FLY-Firmware.git /data/FLY-Firmware
ln -s /data/FLY-Firmware /root/FLY-Firmware

Update the repository if it has already been downloaded:

git -C /data/FLY-Firmware pull --ff-only

4. Flash the erase Flash firmware to clear the old firmware already present on the device:

sudo ~/klipper/lib/rp2040_flash/rp2040_flash ~/FLY-Firmware/RP2040/nuke_universal.uf2

After the command finishes, the device will automatically restart and return to BOOTSEL / UF2 mode. lsusb will show 2e8a:0003 again, and at this point the Flash is already empty.

5. Depending on the communication method and CAN rate, execute only one of the following flashing commands:

USB:

sudo ~/klipper/lib/rp2040_flash/rp2040_flash ~/FLY-Firmware/ToolBoard/ERCF/FLY_ERCF_CANBOOT_USB.uf2

CAN 500K:

sudo ~/klipper/lib/rp2040_flash/rp2040_flash ~/FLY-Firmware/ToolBoard/ERCF/FLY_ERCF_CANBOOT_500K.uf2

CAN 1M:

sudo ~/klipper/lib/rp2040_flash/rp2040_flash ~/FLY-Firmware/ToolBoard/ERCF/FLY_ERCF_CANBOOT_1M.uf2

6. After the flashing success message appears, proceed with the power-off operation.

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Completing the Flash

Power Off First

After flashing is complete, disconnect the toolboard's USB and external power before restoring normal wiring. Do not plug or unplug the toolboard wiring harness while the system is powered on.

After re-powering, the status LED will blink when Katapult starts normally:

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