Random "Timer Too Close" one more time, Sermoon D1 Printer, Creality 4.3.1 Board

Basic Information:

Printer Model: Creality Sermoon D1
MCU / Printerboard: Creality 4.3.1 (stm32f103xe, klipper v0.12.0-404-g80d185c94)
Host / SBC: Raspberry Pi Zero 2W - connected by UART, with Kingston microSD 64GB - temperature during printing around 50C-60C (with radiator)
Klipper: v0.12.0-404-g80d185c94-dirty, MainsailOS 1.3.2 (bullseye)
Additional: active usb 2.0 hub with camera and 2 relays for printer and leds.
Power supply for raspberry, hub and relays is a RS-15-5 Mean Well (15W, 5V, 3A)
klippy.log klippy.log.zip (786.6 KB)
printer.cfg printer.cfg (5.0 KB)

Describe your issue:

All is working good, but sometimes (most often after many hours (e.g. 10h-12h) of printing, but once it also happened after a few minutes from start) I got a well-known and disliked error “Timer too close”, then printer stopped and all hours of print are good to trash. Currently, the problem occurs on average once every 10 prints. Totally in random moment.

I tried before:

  • printing with USB connection (thought that there is problem between usb hub, camera and printer mainboard) now on UART I think it works a little better or maybe it just seems that way to me.
  • printing with disabled camera - not disconnected from hub only disabled service - nothing changed.
  • printing with disabled LEDs (trying to rule out any interference from the additional power supply for the LED)

I read something about microsteps somewhere - what is it, maybe I should change it somewhere? Will it affect print quality or speed?

In klippy.log I can’t notice anything strange, maybe you will see something.

Error in klippy.log: MCU ‘mcu’ shutdown: Timer too close

clocksync state: mcu_freq=72000000 last_clock=1817266789333 clock_est=(25250.339 1815207696595 72004322.994) min_half_rtt=0.000069 min_rtt_time=23940.430 time_avg=25250.339(850.217) clock_avg=1815207696595.854(61219304553.247) pred_variance=5141668.459

Dumping serial stats: bytes_write=94943774 bytes_read=10676032 bytes_retransmit=117 bytes_invalid=0 send_seq=1574939 receive_seq=1574939 retransmit_seq=1574939 srtt=0.001 rttvar=0.000 rto=0.025 ready_bytes=0 upcoming_bytes=0

Dumping send queue 100 messages

Please help, what can I check next…