Skip to main content
Graduate II
January 22, 2025
Solved

STLINK-v3 + CANbus transceiver wiring?

  • January 22, 2025
  • 2 replies
  • 1423 views

This is my setup, STLINKV3+CubeProgrammer (trough CAN) accesing Systembootloader of stm32f405RG

Javier1_1-1737562818363.png

It doesnt work.

Ive tried no Canbus transceiver , digital connection with the onboard diodes from STLINK expansion (blue pcb) and everything works fine.

Javier1_2-1737562946442.png

 

Maybe im messing up the STLINKV3 wiring?

Javier1_3-1737563041394.png

Removing the JP7 CAN-ON jumper and its diodes, looking at UM2448:

Javier1_0-1737562371567.png

Javier1_0-1737564291681.png

 

I wired CN7 CANrx and CANtx, took GND and 3,3V from the "reserved" pins  

 

Javier1_5-1737563561786.pngJavier1_6-1737563583651.png

 

No conexion, and my target board performs SystemReset, so something is arriving to the stm32f405 systembootloader

18:00:05:214 : UR connection mode is defined with the HWrst reset mode
 18:00:07:249 : ST-LINK FW : V3J8M1B5
 18:00:07:250 : Voltage : 0.00V
 18:00:07:256 : Bridge Freq : 48000 KHz
 18:00:07:257 : CAN peripheral parameters
 18:00:07:257 : Mode : NORMAL
 18:00:07:257 : SJW : 1 
 18:00:07:257 : TimeSeg1 : 9 
 18:00:07:258 : TimeSeg2 : 6 
 18:00:07:258 : Prescaler : 24 
 18:00:07:258 : Baudrate : 125 Kbps
 18:00:07:259 : CAN Filter parameters
 18:00:07:259 : IDE : STANDARD
 18:00:07:260 : RTR : DATA
 18:00:07:260 : Activation : ENABLE
 18:00:07:260 : Bank Num : 0 
 18:00:07:260 : ID filter : MASK
 18:00:07:261 : Scale : 32BIT
 18:00:07:261 : Fifo : FIFO0
 18:00:07:266 : s 0 byte(s): 0x79
 18:00:07:273 : s 0 byte(s): 0x79
 18:00:07:274 : s 0 byte(s): 0x79
 18:00:07:274 : s 0 byte(s): 0x79
 18:00:07:275 : s 0 byte(s): 0x79
 18:00:07:276 : s 0 byte(s): 0x79
 18:00:07:276 : s 0 byte(s): 0x79
 18:00:07:276 : s 0 byte(s): 0x79
 18:00:07:276 : s 0 byte(s): 0x79
 18:00:07:276 : s 0 byte(s): 0x79
 18:00:07:276 : Error: ST-LINK error (BRG_TARGET_CMD_TIMEOUT)
 18:00:07:299 : Error: Establishing connection with the device failed
    This topic has been closed for replies.
    Best answer by Javier1

    >>As specified by the note (3) "Do not connect to the target.", reserved pin CN7-pin10 must not be used. It is not a 3.3V signal and it is reserved for STLINK-VSET and its additional boards power supply. STLINK-V3SET cannot be used to provide 3.3V.

    It cannot or it shouldnt?, because i made it work by using the 3v3 available in that pin.

     

    >>Maybe you also need to add  CAN bus terminator resistor.
    My issue was indeed defective EOL resistors on the adafruit modules https://forums.adafruit.com/viewtopic.php?t=214817

    I made everything work as shown in the question, no setup difference but the correct EOL resistors.

     

    2 replies

    Javier1Author
    Graduate II
    January 22, 2025

    Maybe i chose the wrong connector?
    Maybe i need to use the Bridge CN9 

    Javier1_0-1737564650524.png

     

    Hard to know without STLINKv3 cad files

     

    I just tried, that was not the issue

    ST Employee
    February 3, 2025

    Hello Javier1,

     

    As specified by the note (3) "Do not connect to the target.", reserved pin CN7-pin10 must not be used. It is not a 3.3V signal and it is reserved for STLINK-VSET and its additional boards power supply. STLINK-V3SET cannot be used to provide 3.3V.

    Maybe you also need to add  CAN bus terminator resistor.

    Best regards

    Javier1AuthorAnswer
    Graduate II
    February 3, 2025

    >>As specified by the note (3) "Do not connect to the target.", reserved pin CN7-pin10 must not be used. It is not a 3.3V signal and it is reserved for STLINK-VSET and its additional boards power supply. STLINK-V3SET cannot be used to provide 3.3V.

    It cannot or it shouldnt?, because i made it work by using the 3v3 available in that pin.

     

    >>Maybe you also need to add  CAN bus terminator resistor.
    My issue was indeed defective EOL resistors on the adafruit modules https://forums.adafruit.com/viewtopic.php?t=214817

    I made everything work as shown in the question, no setup difference but the correct EOL resistors.

     

    ST Employee
    February 3, 2025

    Hello Javier,

    Good to know the issue was linked to CAN bus terminator.

    Regarding reserved pin CN7-pin10 usage and your question "It cannot or it shouldnt?, because i made it work by using the 3v3 available in that pin.":

    This pin is not 3V3 but 5V. No signal availability is guaranteed for this pin: the signal can be switched off during some STLINK probe activities (such as USB enumeration). No maximum output current can be guaranteed. Please also notice that exceeding the available output current may damage the device or cause communication issues with the host PC (A PC standard USB connector cannot provide more than 500 mA by the USB port and STLINK-V3SET
    can request dynamic current surges during target devices programming).

    Best regards