Stm32f103 watchdog problem

General Discussion
1

Hello everybody. I have a very strange problem with a stm32f103 (SKR Mini E3 V2). If i activate maximum_mcu_duration: 5.0 (maximum) in klipper config I get the following error message "“Scheduled digital out event will exceed max_duration”. This happens almost every time during a print when I switch off an output pin for example my caselight. Everything else is working perfect, also long prints.

This never happens during idle.
I have tried so many things and googled alot, also I am using klipper on several printers and no one shows this behaviour.

What I have tried so far:

  1. No 5V Pin (USB) between RPI and MCU
  2. Tried UART
  3. Deactived heaters (bed and hotend at 0 degree)
  4. Tried another raspberry pi from another printer where everything is working perfect.
  5. Tried several usb cables
  6. Tried another mainboard (skr mini e3 v2)
  7. Tried several output pins, even when there is no load (mosfet & light) the shutdown occours
  8. Reflashed the mainboard
  9. Created a test setup on my workbench with stabilised PSU for RPI and MCU

I really dont know what to do. Most of my printers are running with an octopus and I never had a problem.

I hope someone could help me because I am already searching, testing for about 20 hours.

Thank you very much!
klippy(12).log (890.9 KB)

2

Hello @Zodiak1993 !

Ever thought about using another value?

3

Thank you for your answer. Same behaviour with different values but good aspect!

4

I’m not sure why that would be. I did note two things:

  1. It’s not clear why you are setting maximum_mcu_duration - that is intended as a safety feature to turn off spindles, lasers, or similar in the event of a communication failure between host and mcu. If you don’t need that feature, you are better off not enabling it.
  2. It seems you have customized Klipper (at a minimum by loading external modules into the Klipper source code). You should reproduce the problem using the pristine Klipper code and post a log from that session.

Cheers,
-Kevin

5

Thanks Kevin for your help.

  1. I like this feature because if I shutdown the host everything goes off.
    Motors are off, lights are off and so on. If this is not enabled everything stays at the same state (except heaters of course).
    I am also using it to detect failure of the mcu and shutdown after 30s with an arduino to kill mainsupply. For example if the SSR fails Klipper will go in shutdown, but the heater is still active. After 30s main supply is switched off.

  2. Yeah it is customized. But no other printer (9 printers with klipper) show this behaviour. But of course I will reproduce the problem with pristine Klipper code.

  3. Is it normal, if I use “maximum_mcu_duration” with one pin in the config, that the watchdog is activated for every other pin?

Thanks for your help and for your Canbus support the last time! I love klipper :wink: