STM32F103 UART Bootlader: "Error activating device: KO"

[gadi]

Hello,

I'm new to this STM32 products. We designed custom module with STM32F103CBT6TR. We are facing issue with serial boot loader.

I'm using CH340 UART to USB converter module. 

CH340 MOD TX --> Our Module's RX

CH340 MOD RX --> Our Module's TX

CH340 MOD GND --> Our Module's GND

And our module is powered by USB connector.

Boot mode configuration

Boot 0 is HIGH

Boot 1 is LOW

I'm using STM32cube programmer tool.

When I try to connect our module, I'm seeing the above error. 

Just to confirm CH340 module, I tried that with Nucleo board. With Nucleo board I can see it is able to connect without throwing any error.

I tried other reccomondations which are mentioned in this community post like hold reset button and plug USB and then try pressing connect in the STM32cube programmer. But that also, didn't help. 

Any help will be really appreciated.

Thank you.

[gadi]

Hello,

I tried probing Tx and Rx lines on CH340 module. 

On Tx line I can see pulses like below when I press Connect button on Stm32 Cube programmer. But on Rx line I'm seeing no pulses but it is always high at 3.3V.

[mƎALLEm]

This is the 0x7F byte sent to the STM32:

Frankly I don't know what is happening as I don't have the board at my hands..

Are you sure the chip is functional? do you have a means to connect via Serial wire debug to the chip?

[gadi]

Hello,

Currently, we don't have ST link.  yes, I'm not able verify the chip functionality. 
Chip is getting power. Is there any way to check clock to Microcontroller?

I'm doubting Reset pin. Our Reset should be high and when we press button it should go low and come back high again. But in our case, This RST net is always low even after pressing the button. I'm checking that now. Thanks for your all the replies.

[mƎALLEm · Accepted solution]

The MCU starts from the internal HSI. There is no way to check the MCU clock.

Meanwhile, are you sure about the COM number you are using? COM5?

Please check again in the windows device manager. Does CH340 module correspond to COM5?

I did the same test on a NUCLEO-F103RB board and succeeded with the same CubeProgrammer parameters as yours and succeeded to connect to the system bootloader. I got the same error when COM number is wrong.

Otherwise, I'm running out of ideas .. It could be an issue with your MCU ..

[gadi]

Hello,

thank you so much for your support. It was Reset issue. After fixing it, we board is up.

Regards,

Gadi