[New] CB2 Timer too close

Issue Explanation: Timer too close Error

※Error Message

When using the BTT CB2 mainboard with Klipper, you might encounter the following error:

MCU 'mcu' shutdown: Timer too close This often indicates the host computer is overloaded. Check for other processes consuming excessive CPU time, high swap usage, disk errors, overheating, unstable voltage, or similar system problems on the host computer.

※Cause of the Problem

This error typically indicates a synchronization issue between the host computer (running Klipper) and the MCU (microcontroller unit), where the timer intervals are too close. It is generally not a hardware fault but a configuration issue, especially in systems with higher resource demands. Potential causes include:

1. Host performance: High CPU or memory usage may impact communication efficiency, particularly if the host is running other processes or tasks simultaneously.

2. Communication delays: Factors like USB cable quality or system responsiveness can introduce small delays in communication.

3. System configuration: The default value for the TRSYNC_TIMEOUT parameter in Klipper is set for typical use cases, but in some setups, it may need to be adjusted to better handle high-load conditions.

4. Increased system demand: Adding optional components like Knomi displays, RGB light strips, or cameras can increase the system load, affecting communication timing.

This method, recommended by BigTreeTech, is an official solution to adjust the system’s tolerance and improve stability in more complex setups.

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※Solution

Adjusting the TRSYNC_TIMEOUT parameter in Klipper can alleviate this issue. The default value is 0.025 seconds. Increasing it to 0.05 seconds allows for more time margin to accommodate higher system delays. Below is a step-by-step guide on how to modify this parameter using MobaXterm.

Step 1: Log in to the Host

Follow your existing SSH login guide to access the host running Klipper.

Step 2: Modify the TRSYNC_TIMEOUT Parameter

1. Navigate to the Klipper Directory Enter the following command in the terminal to navigate to the Klipper directory:

   cd ~/klipper

2. Open the mcu.py File Run the following command to open the file in a text editor:

   nano klippy/mcu.py

3. Locate the Target Parameter To find the parameter, use the mouse scroll wheel to navigate through the file. You cannot edit directly by clicking, so use the scroll wheel to move through the file. Look for the following line:

   TRSYNC_TIMEOUT = 0.025

1. Adjust the Parameter Value Change the value from 0.025 to 0.05, so it looks like this:

TRSYNC_TIMEOUT = 0.05

1. Save the Changes

• Press Ctrl + O to save the file.

• Press Ctrl + X to exit the editor.

• it will prompt you with "Save modified buffer?". Press Y to confirm.

• Next, it will ask for the file name to write: klippy/mcu.py. Simply press Enter to confirm and save.

Step 3: Restart the Klipper Service

1. Restart Klipper Enter the following command to restart the Klipper service and apply the changes:

   sudo service klipper restart

2. Test the Printer After the restart, test the printer to ensure the Timer too close error no longer occurs.

This method can effectively address the Timer too close error and improve printer stability.