Basic Information: Printer Model: Custom CoreXY MCU / Printerboard: Custom STM32H7 klippy.log (118.4 KB) Describe your issue: We updated our controller board from one with an Atmel ATSAM3 to a new board based on an STM32H723 running at 480 Mhz and we started getting MCU 'mcu' shutdown issues w…

Found the problem: 480mhz is too fast for Klipper. Slowing down the board to 400Mhz fixed it for good.

[image] tettabeta: The host is is a Celeron PC, which should have plenty of power. Do you use a VM? Apart from that, refer to Timer too close

No VM, checked the checklist: what we found (as written in original message) is abnormal activity. Usb: we tried ferrite, slowing down speed and accels, no other USB device…no way. SBC is supplied with a good industrial PSU (24vdc). As soon as mesh calibration starts system goes amok: timer too c…

[image] tettabeta: MCU / Printerboard: Custom STM32H7 What does this mean? [image] tettabeta: and the latest klipper version cloned from Github (master branch). Does not seem so: Git version: 'v0.11.0-257-ged66982b-dirty' Modified files: src/stm32/gpio.c, src/stm32/stm32f0_i2c.c, src…

MCU: we have been working on a custom motherboard, based on a STM32H7. Home made problem: can you elaborate ? Not offended, just trying to understand what is going on. Brgds

Well, we moved from The general configuration of the printer is unchanged (same speed, same acceleration, same Klipper config), we just updated the pinout definitions. to: We have stuffed in a (probably untested) custom board and modified the Klipper sources and now it is not working like expect…

to: We have stuffed in a (probably untested) custom board and modified the Klipper sources and now it is not working like expected. The hardware as been tested validated, and we are able to print if we skip BED_MESH_CALIBRATE. The source changes are rather simple and we can exclude any issue cau…

You can try to set the TRSYNC_TIMEOUT in mcu.py to .050 from .025, line 218, its a hack but appears to do the job.

Thank you Gruntt. Sadly, no change- BED_MESH_CALIBRATE still crashes the party. :frowning:

[image] tettabeta: why do you say “I have never seen a log like this”? What is unusual? See the paste in my above comment. I have never seen such a pattern before [image] tettabeta: is it possible that a (much) higher clock MCU leads to the host to be overloaded, even with the very same …

Might be the reason why the Octopus Pro with H7 CPUs are capped at 400 MHz by default.

MCU 'mcu' shutdown: Timer too close during BED_MESH_CALIBRATE

General Discussion

Sineos August 2, 2023, 7:52pm 2

Do you use a VM?

Apart from that, refer to Timer too close

Topic		Replies	Views
MCU 'mcu' shutdown: General Discussion	47	1638	December 16, 2024
MCU 'mcu' shutdown: Rescheduled timer in the past - Host Buffer 100% General Discussion	21	1862	October 22, 2022
Sudden MCU Shutdown During Print General Discussion	22	3135	December 15, 2023
Help fixing "Timer too close" shutdown General Discussion	15	689	July 13, 2025
MCU 'mcu' configured for 64Mhz but running at 63Mhz! General Discussion	25	3730	June 21, 2024

MCU 'mcu' shutdown: Timer too close during BED_MESH_CALIBRATE

Related topics