3D printing

Problem:

When using Trinamic drivers with the Marlin 3D printer firmware, you might occasionally experience errors like

Send: N4193 G1 X12.345 Y34.567 E122.15252
Recv: 
Recv: E driver error detected: 0x10136000
Recv: coil short circuit
Recv: 		X	Y	Z	E
Recv: Enabled		true	true	true	true
Recv: Set current	2000	2000	2000	1000
Recv: RMS current	1999	1999	1999	990
Recv: MAX current	2819	2819	2819	1396
Recv: Run current	31/31	31/31	31/31	19/31
Recv: Hold current	15/31	15/31	15/31	9/31
Recv: Global scaler	167/256	167/256	167/256	133/256
Recv: CS actual	31/31	31/31	22/31	19/31
Recv: PWM scale	196716	33095745	65576	33488924
Recv: vsense
Recv: stealthChop	true	true	true	true
Recv: msteps		128	128	128	128
Recv: interp		true	true	true	true
Recv: tstep		171	678	max	1580
Recv: PWM thresh.	24	24	411	13
Recv: [mm/s]		102	102	3	41
Recv: OT prewarn	false	false	false	false
Recv: triggered
Recv:  OTP		false	false	false	false
Recv: off time	4	4	4	4
Recv: blank time	24	24	24	24
Recv: hysteresis
Recv:  -end		2	2	2	2
Recv:  -start		1	1	1	1
Recv: Stallguard thrs	0	0	0	0
Recv: uStep count	62	32	227	497
Recv: DRVSTATUS	X	Y	Z	E
Recv: sg_result	0	0	395	0
Recv: stallguard
Recv: fsactive
Recv: stst		*	*		*
Recv: olb
Recv: ola
Recv: s2gb					*
Recv: s2ga
Recv: otpw
Recv: ot
Recv: Driver registers:
Recv: 		X	0x00:1F:40:00
Recv: 		Y	0x00:1F:40:00
Recv: 		Z	0x80:16:41:8B
Recv: 		E	0x10:13:60:00
Recv: 
Recv: 
Recv: echo:Driver error
Recv: Error:Printer halted. kill() called!
Changing monitoring state from "Printing" to "Error"

Solution:

If the error always occurs at the start of each print, be sure to check your stepper motor setup for actual shorts! Measure the inducitivity using an LCR meter to be sure, it should be around the rated value for your motor! See this post for information about typical stepper motor inductivity.

If the error occurs occasionally, it is recommended in the datasheet that you use more conservative short detection settings.

You need to make the change this in Marlin/src/module/stepper/trinamic.cpp.

Go to the section for the driver type you are using. In my example, this would be

#if HAS_DRIVER(TMC5160)
// ...
void tmc_init(/* ... */) {
   // NOTE: tmc_init() is the function we need to insert code in!
}
#endif

Now insert, just before the TERN(HYBRID_THRESHOLD, /* ... */) line (if such a line does not exist, insert at the end of the function:

// Set more conservative short detection settings
st.shortfilter(3); // 3us SHORT filter
st.s2vs_level(15); // Lowest sensitivity short to supply voltage protection
st.s2g_level(15); // Lowest sensitivity short to ground protection
st.shortdelay(1); // 1.5us instead of 0.75us short delay

These are the most conservative settings possible using this setup.

Now retry your print.

In case this still doesn’t help, you can disable short protection entirely. Note that short protection exists to prevent damage to your stepper motor, your mainboard and your cabling, so you should only disable it if there is no other choice!

In order to disable short protection entirely, insert this code block instead of the conservative setting code block from above:

// Disable short protection entirely
st.diss2g(true);
st.diss2vs(true);

Tested with Marlin version 2.0.9.1

Under certain critical circumstances like thermal runaway protection, Marlin entered a killed state. You typically need to hard-reset the mainboard after entering that state. However, in environments where physical access to the machine, hard-resetting Marlin is not possible, so you might need to implement.

Note that diagnosing & fixing the underlying issue that caused the reset is extremely important and ignoring it might lead to further issues, up to a fire hazard or the destruction of the printer. So be sure to know what you are doing before just.

The following guide was tested with Marlin 2.0.9.1. It should work with most Marlin 2.x versions with minor adjustments.

First, note that as an alternative to hard-resetting the mainboard there is the SOFT_RESET_ON_KILL option which allows you to trigger a soft reset out of kill mode using a button connected to a pin. We won’t delve into more detail on this, since it doesn’t really change the requirement for physical access to the printer.

Open Marlin/src/MarlinCore.cpp and find the minkill(bool) function.

At the end, this function contains a preprocessor-controlled branch of the following structure:

#if EITHER(HAS_KILL, SOFT_RESET_ON_KILL)
  // Branch 1 ...
#else
  // Branch 2 ...
#endif

We will replace this entire branch by these lines:

// Wait for 5 seconds for controller to catch up
for (int i = 5000; i--;) { DELAY_US(1000); watchdog_refresh(); } // 5000*1ms = 3s
// Auto-reset after kill
HAL_reboot();

I prefer to insert the 5-second delay into the reboot logic so no superordinate controller (like a Raspberry Pi running OctoPrint) can miss that the Marlin board has been killed. Although most controllers should be able to detect the killed state from the G-Code, this 5-second delay will simulate the default behaviour of not resetting at all after the killed state has been reached. However note that in case you absolutely need to reset ASAP after the kill state has been reached, it’s typically safe to omit the wait loop.