Howdy,

I'm finally testing my dirk bike ECU. It worked wonderfully till a point,
where the engine turned off and didn't want to start anymore. I thought it
was maybe a bad/cold soldering, so I just replaced it with the original and
didn't bother anymore for that day.

But when back in the lab, the ECU worked! I made a lot of tests and my ECU
proved to work absolutely perfectly, even when hammered. ;) So what was it
that made it suddenly stop working?

I immediately recalled where it happened (I even have GPS logs): I was in a
dried river bed full of rocks, and a thick gray cable was making impossible
for me to pass. I stopped in front of it, the engine turned off but I thoug=
ht
it was just because of carburetion problems (too low idle), etc..

I noticed it was a very high tension/current cable that fell down from a
tower. Regardless of that, it felt natural for me to grab it with my hand,
raise it, and thus push the bike beyond the obstacle. Then I tried to start
the engine but, as said, it didn't run, so (as I wasn't alone and everybody
was in a hurry) I quickly swapped the ECU with the original, and the engine
restarted.

I am thinking to return there but it means to do 200 kms alone.. it's not
safe to do it off road, but thanks to the GPS log I found a way to do 99% o=
f
those 200km via asphalt, and I will return there to clear my doubts.

I tried to disturb the ECU in my lab with 230V 2000W appliances, but
evidently that wasn't enough. I will have to return there, near that cable,
and see if the fault is repeatable, also because I've been using it for
many hours today and it worked flawlessly.

But as it's very distant from home, I want to make 1 trip and 2 jobs: I wan=
t
to bring with me a 2nd prototype, with a supposed workaround/fix/improvemen=
t
in place, and see if this new prototype is immune enough to that terribly n=
oisy
cable.

Will shielding help? It probably won't, as it's just 50Hz magnetic field I =
think,
but I wish to ask you.

Will placing the Xtal nearer to the MPU help (currently 10mm), as well as m=
oving
the Xtal caps to the bottom of the PCB board, so they're as near as possibl=
e to
the Xtal and MPU too? (currently the caps are on the same PCB side of the X=
tal
and MPU and are comprehensibly not really close (another 10mm) but, worse, =
their
ground return doesn't go into the MPU Vss pin, but to the opposite side of =
the
PCB). Can this have made a difference?

What else would you make to ensure maximum immunity to the noise coming fro=
m
a very high tension/current cable that is there although it should not be t=
here?

It's a chance I have to make my circuit more robust and gain experience bef=
ore
they fix that cable (because it can't be there, it's dangerous, and I will =
notify
the local police about it then, i.e. hopefully tomorrow morning already).

Oh yes this time I won't touch it, I will reach it near with my bike and EC=
U but
not grab it anymore. If it was the cause of the malfunction, it indeed did =
it even
at 1 meter of distance, so I'll do it from a small distance.

Cheers,
Mario

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