Motor Suddenly Stops When Touching the Micro Controller and XTAL

[mimho]

Hey there!

I know I have already asked a lot of questions so I need to tell the ST family how much grateful I am!

Recently, after resolving all the errors related to the MCSDK, When we touch either the uC or XTAL, the motor stops abruptly and violently.

It happens every time and the weird point is that the micro doesn't reset and we get no error from the FW.

we use both MC_GetCurrentFaultsMotor1() and MC_GetOccurredFaultsMotor1() functions and they both return zero.

we implemented an LED for debugging purposes and it continues blinking showing that the micro doesn't reset(We also inserted a considerable delay before any initialization to make sure of that)

Do you have any idea of what is happening? Is there anything wrong with our PCB or its grounding?

Any suggestion would be awesome! Thanks

[unrealistic]

no idea,i feel it is some sort of micro shorting out of the pins as finger is conductive

I had it happened before with a branded esc, was connected to 3s2p battery and i touch random spot while the motor was spinning to check for heat and was kind of surprise that touching the crystal will stop the motor so as always my itchy hand just kee poking it and BOOM the mosfets short itself out and burn out the motor windings too, lots of smoke

I learn the hard way, nvr touch with bare hands. just a clear tape cover it and touch.

I touch a 12v powered linksys router pcb and fried the buck regulator too with bare hands, lucky it survived after ic replacement.

In short dont touch with bare hands especially with sweaty hands

[mimho · Accepted solution]

That was a comprehensive response, thanks for your reply.

So you're telling me that it may not be a problem on its own and it had happened on a branded ESC before?

To elaborate, without touching, everything is perfect, whenever we want to reset the micro for some reasons, the motor stops violently before even pressing the reset pin and we suddenly realised that it happened when getting close to the micro or the crystal.

So We just need to touch the board with care?