Tip

• SB2040 PRO V3 is pre-flashed with Katapult firmware for CAN connections at a rate of 1M from the factory.
• The SB2040 PRO V3 CAN-connected Katapult firmware supports rates of 500K and 1M. You can reflash it if needed.
• Katapult Firmware Flashing

Firmware Flashing Instructions

• The SB2040 PRO V3 can connect to the host using either RS232 or CAN.
• RS232 and CAN require a connection via XT30(2+2)-F.
• Below is the XT30(2+2)-F data cable style.

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Notes

• To flash the mainboard firmware, you need to flash Klipper through Katapult.
• If you are sure the mainboard already has Katapult flashed, there is no need to flash the Katapult firmware at the end.
• You can quickly press the reset button twice and check if an LED on the mainboard blinks. If it does, it means the mainboard has entered Katapult firmware mode.

Select Firmware Type

Please confirm the connection method first.

• If you need a CAN toolboard: choose CAN firmware.
• If you need an RS232 connection: choose RS232 firmware.
• Only one of the two firmware types can be selected; do not flash both simultaneously.

Firmware Type	Applicable Scenario	Advantages	Confirm Before Choosing	Operation
CAN Firmware	When a CAN toolboard is needed	Supports connecting multiple devices via the CAN bus	Confirm that the host supports CAN, and prepare a UTOC or USB-CAN bridge board	Compile CAN Firmware
RS232 Firmware	When an RS232 connection is needed	Stable communication, simple configuration	Requires RS232 connection devices such as G2T or UTOR	Compile RS232 Firmware

Katapult Firmware Notes

Name Explanation

Katapult was formerly known as CanBoot, and both names may appear simultaneously in older tutorials or firmware names.

Katapult is a bootloader used to boot and update Klipper:

• Katapult itself cannot be used as a Klipper MCU; after flashing, you still need to write Klipper firmware that matches the hardware and communication method.
• Supported tool boards can enter Katapult by quickly double-pressing the RESET button; after entering, there is usually a status light blinking.
• CAN, RS232, and USB use independent Katapult firmware; you cannot simply modify file names or mix them directly.
• For CAN firmware, you must also select the correct bus speed, with common speeds being 500K and 1M.