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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
Associate II

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?

2 REPLIES 2
Ozone
Lead II

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
Associate II

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?