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Visitor II
December 27, 2022
Solved

Why the leg (pd8) is connected to ground in the schematics

  • December 27, 2022
  • 7 replies
  • 2179 views

can some one please tell me why is the schematics the pd8 is connected to gnd?

here is a picture of the schematics0693W00000Y6vykQAB.png 

    This topic has been closed for replies.
    Best answer by KDJEM.1

    Hello @YShko.1​,

    By default the PD8 and PD9 are used as GPIOs.

    And when solder bridges SB29/SB30 are OFF, you can use PD8 and PD9 as GND and VDD as shown in the UM2324 and precisely in table 10.

    0693W00000Y6wDzQAJ.pngBut I notice a contradiction between the UM2324 and the schematic, Is it PD8 connected to GND or VDD?

    I reported this issue internally.

    Internal ticket number: 141998(This is an internal tracking number and is not accessible or usable by customers). 

    Kaouthar

    7 replies

    KDJEM.1Answer
    Technical Moderator
    December 27, 2022

    Hello @YShko.1​,

    By default the PD8 and PD9 are used as GPIOs.

    And when solder bridges SB29/SB30 are OFF, you can use PD8 and PD9 as GND and VDD as shown in the UM2324 and precisely in table 10.

    0693W00000Y6wDzQAJ.pngBut I notice a contradiction between the UM2324 and the schematic, Is it PD8 connected to GND or VDD?

    I reported this issue internally.

    Internal ticket number: 141998(This is an internal tracking number and is not accessible or usable by customers). 

    Kaouthar

    YShko.1Author
    Visitor II
    January 1, 2023

    Thank you very much!!

    Super User
    December 27, 2022

    Next time tell us it's a Nucleo board.

    The solder bridges SB29 and SB30 for the 'G070 should be unconnected, i.e. those pins are not connected to GND and VDD. The board is used also for other 'G0xx models, and some of them have power pins as pins 40/41 rather than GPIO.

    JW

    YShko.1Author
    Visitor II
    January 1, 2023

    Thank you very much!!

    Super User
    December 27, 2022

    Hi Kaouthar,

    I believe that the symbols used for SB29/SB30 on the above schematics mean "disconnected solder bridge" - note that the arc within the symbol is not continuous, in contrast to SB20.

    JW

    @KDJEM.1​ 

    Technical Moderator
    December 27, 2022

    Hello @Community member​,

    You are right.

    By default the SB29/SB30 are disconnected solder bridge because the arc is not continuous, in contrast SB20.

    Thank you for your contribution.

    Kaouthar

    Technical Moderator
    January 10, 2023

    Hi @YShko.1​,

    The connections are set as described below:

    - PD8 is well connected to SB30 which is connected to GND

    - PD9 is well connected to SB29 which is connected to VDD

    I have already raised internally the UM2324 typo for correction in next release.

    Thank you for your contribution in STCommunity.

    Kaouthar

    Super User
    January 10, 2023

    Ouch.

    JW​

    Technical Moderator
    October 15, 2025

    Hello @YShko.1 ,

     

    The issue is fixed in UM2324 Rev 5.

    KDJEM1_0-1760524423904.png

     

    Thank you.

    Kaouthar