Feature Request: Warning for multiple driver entries

Features
1

Hello, I encountered a problem while setting up a CAN system that could pose a significant security risk to the printer in question. When setting up an EBB SB2209 RP, I used the default configuration from BTT. The default configuration contains the following entry:

[tmc2209 extruder]

uart_pin: EBBCan:gpio20

run_current: 0.650

stealthchop_threshold: 999999

I had already entered a different [tmc2209 extruder] with a different uart_pin in my printer.cfg and overlooked the fact that there were now two entries.

Klipper didn’t issue a warning, and the printer was able to print normally. Only after about 30 minutes did the extruder get so hot that it started to melt the filament in the extruder (G2E). Even after aborting the print and deactivating the steppers, the extruder motor remained very hot.

Apparently, if a double driver entry is present, the extruder motor is fired at both current levels, which leads to overheating after a short time.

Without a clogging sensor, I believe this poses a significant fire risk.

It would therefore be helpful if Klipper implemented a safety test to check for double feeds in the extruder drivers.

2

Hi @Biffes ,

This isn’t a bug. Subsequent config sections will overwrite the repeated parameters in them. For example:

[tmc2209 extruder]
uart_pin: some_pin
run_current: 0.25
stealthchop_threshold: 99999

# Later in config
[tmc2209 extruder]
run_current: 0.50

What Klipper sees in this case is:

[tmc2209 extruder]
uart_pin: some_pin
run_current: 0.50 # Updated run_current from second entry
stealthchop_threshold: 99999

Klipper never sees duplicate parameters, only the ones listed last in the config.

Then Klipper would see the section with the latest uart_pin setting. I’m guessing the issue is that Klipper connected to a different TMC driver than the extruder (if the uart_pin didn’t point to a TMC at all I would expect a different error). Then, things like current, microsteps, and stealthchop wouldn’t get updated on the actual extruder TMC2209.

Could you post the two [tmc2209 extruder] sections so we can diagnose the issue? Also a klippy.log would be helpful.

3

This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.