Hi, I use the core-g431kbt6 which I feed at 10 volts between the Vin pin and the gnd. I would need to connect with the usb via stm Studio to monitor some variables, but when I do the card is reset. Is there any way to avoid this reset?

[Mbert.1]

Hi, I use the core-g431kbt6 which I feed at 10 volts between the Vin pin and the gnd. I would need to connect with the usb via stm Studio to monitor some variables, but when I do the card is reset. Is there any way to avoid this reset?

[Ozone]

I don't know that specific board.

But what I find strange, the user manual does nowhere specify the supply voltage range, nor current consumption.

I used to have strange effects when trying to supply a MCU board with attached LCD display through the debugger, due to current limitiations.

So, I would check the supply voltage and current consumption upon USB connect.

[Mbert.1]

hi, ozone thanks for the reply!

Reading the UM2397 manual on page 12 chapter "Power supply" describes the possibility of powering the core through Vin in a voltage range of 7V-12V, I power it at 10v (the power supply can supply 500mA sufficient current for a core). The card then turns on and works, I need to read some variables, after a few minutes from switching on then via the USB I connect to the card AND WHEN I DO THIS THE VARIABLES ARE RESET (this is not a power problem to be of course I monitored the Vdd voltage of the µ through an oscilloscope, the power supply is constant at + 3.3V). I monitored with osilloscope so the Nrst signal when I insert the USB into the PC someone sends a reset signal. Thinking it was ST-Link I tried to remove the resistor R4 (attached diagram), (to remove any connection between µ and ST-LINK) but nothing has changed, when I insert the USB into the computer the variables are reset. SOMEONE KNOWS HOW TO PREVENT THIS FROM HAPPENING?