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How do I reproduce EMI-related problem at my place? Also smoke
Posted: Thu Nov 16, 2023 3:32 am
by AndreyB
Back in 2022 a fatal error caused by specific variable speed shop fan was reported
https://github.com/rusefi/rusefi/issues/4310 it's unfortunately still being reproduced.
What shall I do next? Go back with an oscilloscope to confirm noise on 12v power supply lines? Should I go back with $5 aliexpress USB isolator which claims to have ADUM3160?
How can I reproduce this at home say for $500 or less?
Re: How do I reproduce EMI-related problem at my place?
Posted: Thu Nov 16, 2023 7:32 am
by JRD McLAREN
...as I'm see ... it is hellen88bmw ..??
what kind of ignition coil (or ign. pack) BMW have ..??
now I have one totally burned Ecu Master EMU SIlver (a.k.a. VEMS) ..from BMW
..and few VEMS ecu, was destroyed the same way, cause EMI, aprox. three years ago.
This "big square" coil has problem -
https://accessoriesspares.co.za/product/ign-coil-bmw-e46-m-series-325-3pin/
new "small round" coil is ok -
https://accessoriesspares.co.za/product/ign-coil-elect-bmw-l-rover-3p-2/
Re: How do I reproduce EMI-related problem at my place?
Posted: Thu Nov 16, 2023 2:37 pm
by AndreyB
Back in 2022 it was hellen88can but this year is the small-can-board without igniters without coil control at all.
Re: How do I reproduce EMI-related problem at my place? Also smoke
Posted: Thu Nov 16, 2023 2:58 pm
by AndreyB
Well, wider context: we have two separate incidents of smoke recently.
https://github.com/rusefi/rusefi/issues/5728 and
https://github.com/rusefi/rusefi/issues/5729
We run a manual test and results are claiming that hard fault would have stopped pins and NOT caused smoke
https://github.com/rusefi/rusefi/issues/5723
Looking for ideas on what to do next. We will implement stm32 own hardware watchdog maybe we are legit hanging the code flow somehow? Not sure
My case of smoke I know DC motor signal was registering on VR input maybe crazy inputs have failed to decode enough to cause smoke? See note on
https://github.com/rusefi/rusefi/issues/5723
Overall the big question is what kinds of negative testing can we do how.
Re: How do I reproduce EMI-related problem at my place? Also smoke
Posted: Thu Nov 16, 2023 4:45 pm
by Dron_Gus
EMI will not 100% lead to HardFault.
EMI can cause PLL or oscillator failure - code execution stops.
So SW is not a solution.
Use HW timers for one-short pulse generation. Still can stuck active in case of PLL/clock issue.
Use special IC. MC33810 has several protections for ign outputs.
Re: How do I reproduce EMI-related problem at my place? Also smoke
Posted: Thu Nov 16, 2023 4:48 pm
by Dron_Gus
Negative test - short oscillator. ECU should stop driving everything. I guess we have no fallback to internal oscillator enabled.
Re: How do I reproduce EMI-related problem at my place? Also smoke
Posted: Thu Nov 16, 2023 4:56 pm
by AndreyB
Dron_Gus wrote: ↑Thu Nov 16, 2023 4:45 pm
EMI will not 100% lead to HardFault.
Good chance we have more than one issue?
variable FAN situation seems to be trigger specifically by USB, so maybe EMI makes USD driver hard fault maybe the driver is not handling something properly?
and the coils stuck open could be a totally different story
Re: How do I reproduce EMI-related problem at my place? Also smoke
Posted: Thu Nov 16, 2023 4:59 pm
by AndreyB
Dron_Gus wrote: ↑Thu Nov 16, 2023 4:48 pm
Negative test - short oscillator. ECU should stop driving everything. I guess we have no fallback to internal oscillator enabled.
https://github.com/rusefi/rusefi/issues/5730
Re: How do I reproduce EMI-related problem at my place? Also smoke
Posted: Thu Nov 16, 2023 5:02 pm
by AndreyB
Dron_Gus wrote: ↑Thu Nov 16, 2023 4:45 pm
Use special IC. MC33810 has several protections for ign outputs.
https://github.com/andreika-git/hellen-one/issues/207
Re: How do I reproduce EMI-related problem at my place? Also smoke
Posted: Thu Nov 16, 2023 7:15 pm
by JRD McLAREN
sometimes is not problem in ECU .. itself ..
I have one scenario on 4AGE engine, Hall on crank, 4 CDI coils
modified stock wiring loom ...
Never runs properly, kills 3 USB ports ... and many many hall sensors and spark plugs..
It must be totally reworked ..
VR on crank, brand new wiring loom must be created
and wires for CDI coils must be shield, and routed separately from all other wires