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Visitor II
November 25, 2025
Question

TCPP03-M20 with STM32G0B1CBT6 failed to connect

  • November 25, 2025
  • 6 replies
  • 298 views

Hello Expert,

 

Could you please provide guidance on the issue below? 

 

We are using the following setup:

- MCU: STM32G0B1CCTx

- Software: X-CUBE-TCPP 4.2.0 with USBPD Application 4.2.0 Dual Role

- Board Part: TCPP0203 v1.2.3

 

We are developing a USB PD board.

When we plug in an Android smartphone (USB Type-C port), the phone does not detect the connection.

Attached is the log showing three plug-in/plug-out attempts.(we plug in and out 3 times)

From the log, it appears that after attachment, the connection detaches immediately, then the roles switch, followed by another detachment.

We have already tried increasing the CAD source/sink toggle time from 100 ms to 144 ms, but the issue persists.

Could you advise on possible causes or solutions? Thanks.

 

DEBUG 86569 0 -- BSP_USBPD_PWR_SetRole : SNK -- 96
DEBUG 86609 0 -- BSP_USBPD_PWR_SetRole : SRC -- 97
DEBUG 86653 0 -- BSP_USBPD_PWR_SetRole : SNK -- 98
DEBUG 86693 0 -- BSP_USBPD_PWR_SetRole : SRC -- 99
DEBUG 86705 0 -- BSP_USBPD_PWR_VBUSInit -- 100
DEBUG 86705 0 -- BSP_USBPD_PWR_SetPowerMode -- 101
DEBUG 86706 0 -- Normal -- 102
CAD 86706 0 USBPD_CAD_STATE_ATTACHED_WAIT 103
CAD 91053 0 USBPD_CAD_STATE_DETACH_SRC 104
DEBUG 91053 0 -- BSP_USBPD_PWR_VBUSDeInit -- 105
DEBUG 91053 0 -- GDP/GDC setting : default -- 106
DEBUG 91053 0 -- BSP_USBPD_PWR_SetPowerMode -- 107
DEBUG 91053 0 -- Low Power -- 108
CAD 91053 0 USBPD_CAD_STATE_SWITCH_TO_SNK 109
DEBUG 91055 0 -- BSP_USBPD_PWR_SetRole : SNK -- 110
CAD 91055 0 USBPD_CAD_STATE_DETACHED 111
DEBUG 91097 0 -- BSP_USBPD_PWR_SetRole : SRC -- 112
DEBUG 91141 0 -- BSP_USBPD_PWR_SetRole : SNK -- 113
DEBUG 91181 0 -- BSP_USBPD_PWR_SetRole : SRC -- 114

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    6 replies

    PaulMinhAuthor
    Visitor II
    November 26, 2025

    When we try to plugin/out quickly, we chould see "USBPD_CAD_STATE_ATTACHED" state but not always.

     

    CAD375960USBPD_CAD_STATE_ATTACHED_WAIT1627
    CAD377180USBPD_CAD_STATE_ATTACHED1628
    NOTIF377180USBSTACK_START1629
    DEBUG377180ADVICE: USBPD_DPM_Notification:1041630
    EVENT377180EVENT_ATTACHED1631
    DEBUG377180VBUS ON1632
    DEBUG377180-- BSP_USBPD_PWR_VBUSOn --1633
    DEBUG377210-- GDP/GDC setting : SRC --1634
    DEBUG377210ADVICE: USBPD_DPM_Notification:1041635
    PE377210PE_SRC_STARTUP1636
    NOTIF377210POWER_STATE_CHANGE1637
    DEBUG377210ADVICE: USBPD_DPM_Notification:901638
    PE377210PE_SRC_SEND_CAPABILITIES1639
    OUT377230SOP PD3s:018    H:0x41A1    (id:0, DR:DFP, PR:SRC) SRC_CAPABILITIESDATA: 2C91013F2CD102002CB1040064400600
    Option: UNCHUNKDRDUSBEPWUSBSUSPDRP
     [1] Fixed : 5V - 3A
     [2] Fixed : 9V - 3A
     [3] Fixed : 15V - 3A
     [4] Fixed : 20V - 1A
    1640
    OUT377250SOP PD3s:018    H:0x41A1    (id:0, DR:DFP, PR:SRC) SRC_CAPABILITIESDATA: 2C91013F2CD102002CB1040064400600
    Option: UNCHUNKDRDUSBEPWUSBSUSPDRP
     [1] Fixed : 5V - 3A
     [2] Fixed : 9V - 3A
     [3] Fixed : 15V - 3A
     [4] Fixed : 20V - 1A
    1641
    OUT377270SOP PD3s:018    H:0x41A1    (id:0, DR:DFP, PR:SRC) SRC_CAPABILITIESDATA: 2C91013F2CD102002CB1040064400600
    Option: UNCHUNKDRDUSBEPWUSBSUSPDRP
     [1] Fixed : 5V - 3A
     [2] Fixed : 9V - 3A
     [3] Fixed : 15V - 3A
     [4] Fixed : 20V - 1A
    1642
    PE377290PE_SRC_DISCOVERY1643
    IN381880HRST1644
    NOTIF381880HARDRESET_RX1645
    DEBUG381880ADVICE: USBPD_DPM_Notification:301646
    PE381880PE_HARD_RESET_RECEIVED1647
    NOTIF381880USBSTACK_STOP1648
    DEBUG381880ADVICE: USBPD_DPM_Notification:1051649
    PE381880PE_SRC_HARD_RESET_TIMEOUT1650
    Technical Moderator
    November 27, 2025

    Hello @PaulMinh 

    Did you implement the user code provided in this example? Would you share minimum schematics with USB C connector? Compare with reference board design to narrow down the issue. 

    PaulMinhAuthor
    Visitor II
    November 28, 2025

    Hello FBL, 

    We followed https://www.youtube.com/watch?v=mJ4VX_2B6wE&t=839s , for our custom board (configured as in  MX_Config.PNG, SCH.pdf).

     

    PaulMinhAuthor
    Visitor II
    December 4, 2025

    Hello FBL, 

    What conditions, order to change from this state "USBPD_CAD_STATE_ATTACHED_WAIT" to "USBPD_CAD_STATE_ATTACHED"?

    We concern there is an unstable internal resistor; debounce failed and then unable to ATTACHED.

    May you suggest how to debug and fix this issue? Thanks.