Help connecting to STM32 on Cube Programmer

[Math86]

Hello everyone,

I have a PCB with an embedded STM32F103 on it. The PCB provides access to some ports on the side. Those are linked to VDD, PA9, PA10, PA13, PA14 and GND.

I tried connecting to it with Cube Programmer using a FT232RL as pictured below :

 

The connections are :

3.3 v -- VDD

GND -- GND

RX -- PA10

TX -- PA9

When I try to connect with Cube Programmer it shows an error :

I tried all baud rates as I have no idea which one I should use but still no luck.

On the PCB it looks like pin boot 0 is connected to a resistance which is connected straight to ground and same for pin PB2.

Any idea on what I am doing wrong ? (I'm fairly new to this so it might be a stupid mistake)

Thanks in advance !

[Tomas SIRUCEK]

Hi,

If You need to connect to MCU using UART, You need to first enter embedded bootloader. To do so, You need to connect BOOT0 pin to VDD and then reset MCU. Then it should be possible to connect to MCU from CubeProgrammer.

Have a nice day,

Tomas

[Tesla DeLorean]

Given the effort to obfuscate the part number,and lock the device to a specific vehicle or VIN#, I'd imagine the part is locked down so you can't read out the firmware.

[Math86]

Fair point, I think so too. ​Would the error mean that the MCU is locked ?

[Math86]

Would it be the same procedure if I tried with a ST link ?​

[Tomas SIRUCEK]

Using ST Link and SWD interface (SWDIO and SWCLK pins), You do not need to pull BOOT pin high. If it will not connect, try to use reset pin as well and use option "Connect Under Reset".

[Tomas SIRUCEK]

If this will not work either, then the MCU is probably locked (Readout Protection Lvl 2) and there is nothing, You could do to make it work again.

[Math86]

I see. Thanks a lot for the insight.​

[Tomas SIRUCEK]

You are welcome.

Have a nice day