RS232 Firmware Connection Guide

Firmware Preparation

• Before entering RS232 mode, please first flash the RS232 firmware pre-compiled for the toolboard onto the toolboard via a Type-C data cable.

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Wiring Steps

Setting the DIP Switches

1. Power Off Safely: Ensure the toolboard is completely disconnected from the power source before operation.
2. Locate DIP Switches: Flip the toolboard over and locate the group of DIP switches on the back.
3. Switch Mode: Set all DIP switches to the specified position for RS232 mode (see image below).

Warning

• If the DIP switch state is changed, the RS232 firmware must be re-flashed, otherwise communication will fail.
• If the correct firmware was previously flashed and the DIP switches have not been changed, re-flashing is not necessary.

Connecting Cables

1. Keep Power Off: The device must remain powered off throughout the entire wiring process.
2. Required Cable: Prepare an XT30(2+2)-F 4-core cable. The core definitions are as follows:

Wire Color	Signal	Connection Target
Red	VCC (Power Positive)	12V–24V Power Supply Positive
Black	GND (Power Negative)	Power Supply Negative
Yellow	IN (Signal Input)	OUT pin of the UTOR module's RS232 expansion port
White/Green	OUT (Signal Output)	IN pin of the UTOR module's RS232 expansion port

3. Complete Connection:
   • Insert the cable's male connector into the corresponding interface on the toolboard.
   • Insert the cable's female connector into the corresponding interface on the UTOR module.
   • Connect the UTOR module to the host computer (e.g., FLY Pi, Raspberry Pi, or PC) using a USB cable.

Checking Common Ground

• Use a multimeter in Continuity/Resistance mode to measure between the following two points:
  • GND on the toolboard
  • GND on the host computer
• It is essential to ensure these two grounds are connected (resistance close to 0Ω). If they are not connected, communication cannot be established. Please check if the wiring is complete and secure.

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Searching and Configuring Toolboard RS232 ID

🔴 Important Preparation

Warning

1. Firmware Requirement: The toolboard must be flashed with the RS232 firmware, otherwise communication is impossible.
2. Mandatory Common Ground: ⚠️ You must ensure the GND of the toolboard is connected to the GND of the mainboard (using the same 24V/12V power supply will achieve this).

📌 Hardware Notes

• Only D8, D8PRO, C8P mainboards natively support the RS232 interface.
• Other mainboards require connection via a UTOR or G2T module (this tutorial uses UTOR as an example).

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🔍 Steps to Search for RS232 ID

Step 1: Access the Host Computer

1. Open a browser and enter the host computer's IP address (e.g., 192.168.101.179).

Step 2: Open the Configuration File

2. Go to the left-side menu, find and click on printer.cfg:

Fluidd Click the {…} icon.

Mainsail Click the "Machine" menu.

Step 3: View Device List

3. Click the DEVICES button in the top right corner:

Step 4: Refresh Serial Devices

4. Click SERIAL and refresh the list:

Fluidd

Mainsail

Step 5: Copy the RS232 ID

5. Find the device containing ttyUSB and copy its Path_by_hardware value:

Fluidd Confirm the presence of ttyUSB and Path_by_hardware.

Mainsail Confirm the presence of ttyUSB and Path_by_hardware.

Note for UTOR Users

• When connected via UTOR, there are usually two candidate IDs. Try each one to determine the correct ID.
• Click the arrow icon next to the ID to copy it.

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⚙️ Configuring the RS232 ID into the Firmware

Configuration Note

• In the configuration below, toolboard refers to the toolboard name. Please replace it according to your actual situation.
• The toolboard configuration should be [mcu toolboard], and the mainboard configuration is [mcu]. Do not confuse them.

Reference Configuration:

Configuration Template

[mcu toolboard]
serial: <Replace here with the actual ID you queried>
baud: 250000
restart_method: command

Configuration Steps:

1. Paste the copied ID after the serial: parameter.
2. Click the SAVE & RESTART button in the top right corner to save and restart Klipper.

Important Warning

• All IDs in this document are examples. It is strictly forbidden to copy and use them directly.
• You must fill in the hardware ID you actually obtained.
• The following IDs are invalid examples and must not be used:

  serial: /dev/serial/by-id/usb-1a86_USB_Serial-if00-port0

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Important Note: About the RS232 ID

Key Point

The RS232 ID you searched for is the ID of the UTOR module itself, not the ID of the toolboard.

Crucial Understanding

• This ID represents the connection interface between the UTOR module and the host computer.
• The host computer uses this ID to tell the UTOR module: "Please connect to the toolboard through this interface of yours."
• Regardless of whether the toolboard is connected, as long as the UTOR module is connected to the host computer, this ID will exist.

In Simple Terms

Host Computer → [UTOR Module (ID)] → Toolboard

You are configuring the address of the middle box (UTOR), not the address of the toolboard.

Practical Tips

• The ID can be found as long as UTOR is connected, but communication only works if the toolboard is properly connected.
• ID changes usually occur because the UTOR was moved to a different USB port or the system was restarted.
• When configuring, ensure the toolboard is correctly connected and powered.