Flashing Nucleo-L073rz using the system bootloader.

[ABans.3]

Hello,

I have the project in which I need the flash the stm32L0 with uart using the system bootloader. I have settted required option bytes. I make the boot 0 pin high and the sytem is getting into the bootloader mode. I attach the usb to uart converter and provided the external 5v supply. The problem is I am only getting able to connect to the bootloader with the uart1 ( pin A9 and A10), at 9600 baud rate. I cannot goes higher that. Also the other UART2(pin A2 and A3), are not being detected at any baud rate.

I am testing all this on Nucleo -L073Rz board.

[Kamil Duljas]

Take photo of your UART to USB and your board connection ​

[Kamil Duljas]

Hi, Algorithm of bootloader connection listens for signals. When you are trying to connect using 9600 then the board calibrate yourself and customize yours settings to 9600. If you disconnect, change baudrate and reconnect you get error because the board expect 9600. First you must reset board (using reset button for example) then change baudrate. The same with UART port. first reset then try connect with new settings.

[Kamil Duljas]

In case of USART2. look at board manual:

https://www.st.com/resource/en/user_manual/um1724-stm32-nucleo64-boards-mb1136-stmicroelectronics.pdf

try using CN3 connector:

[Kamil Duljas]

Did you resolve the issue?

@ABans.3​ ​

[ABans.3]

@Kamil Duljas​ Thanks for your support. I appreciate that!

I use esp32 instead for the regular ftdi, it works for 115200 baud rate.

for Uart2 I need to verify it. I was busy in developing my app.

Thanks again for supporting me.

[Kamil Duljas]

Nice 🙂 please marks some post as best answer due to close issue