STLINK-v3 + CANbus transceiver wiring?

[Javier1]

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

It doesnt work.

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

Maybe im messing up the STLINKV3 wiring?

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

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

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

[Javier1]

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

Hard to know without STLINKv3 cad files

I just tried, that was not the issue

[AM]

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

[Javier1 · Accepted solution]

>>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.

[AM]

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