Programming NucleoG474RE via bootloader

[EliazLB]

Hello,

I am currently trying to program a nucleo board using USART. For this I am using the bootloader and Cube Programmer. 

I first developed a program and tester it by programming via st link. My program worked with no problem. I then tried to program using UART. 

I was able to connect but as soon as I started programming, I get the message Error :GETID command not acknowledged and then the nucleoboard is disconnected.

Here are my settings and the boot0 pin is tied to 3.3V.

When I program I can see on the oscilloscope that some part of the program is on and working but not fully as well.

Any idea ?

Thanks very much

[Tesla DeLorean]

Try a lower baud rate.

You get one shot per reset to communicate with the device and have it auto-baud the 0x7F data pattern.

Perhaps use something like Real Term to send/show HEX BYTES, and send the pattern manually, and check for 0x79 response code.

Disturbances to other pins noted in AN2606 may also be recognized as first-contact, so check the pins/uart you are involving in your test/evaluation

[ahsrabrifat]

Double-check the UART wiring between the Nucleo and the USB-to-Serial converter or the host:

• TX from USB-Serial → RX of STM32

• RX from USB-Serial → TX of STM32

• GND connected between both boards

[EliazLB]

I've tried both 9600 and 1200 bauds but it doesn't change a bit.

And I've tried using Real term but it doesn't seem to work either.

I've checked with one of the example to use USART via hyperterminal and that seems to work.

[Maryem]

Hello @EliazLB ,

I attempted to reproduce the issue on my end, but everything seems to be working fine.

Could you please provide the bootloader version ? Additionally, if possible, could you share your binary file? 

Thank you,

Maryem.

[EliazLB]

Hi,

The bootloader protocol version is 3.1 if that's what your asking for.

I saw a slight difference between your settings and mine which is that you didn't check the "run after programming" box. I tried to program the nucleo without the box checked and there was no problem. But as soon as I pressed the reset button I got the same problem as earlier.

So the problem might come from my code.

I've attached the binary file I'm programming onto the nucleo.

Thank you

[Maryem]

Thank you for your feedback.

Actually, I was referring to the bootloader information you can find when connecting the target via ST-Link.

Also, thanks for pointing out the "Run after programming" option being enabled. 

Could you please confirm whether you receive the message "File download complete" before encountering the error message?

Maryem.

[EliazLB]

Here is all the informations : 

I do get both messages :

- "download verified successfully"

- "File download complete"

And after both messages are closed does the error message appear.

[EliazLB]

Ok, I don't know why I never checked it, but despite the error message, the program appears to be working. 

I tried with the example GPIO_IOToggle and the led turns on and off as it is supposed to...

The reset buttons seems to be working but only once out of every 10 times I press it.

[Maryem · Accepted solution]

This is normal behavior since the application starts running after flashing. The device disconnects because the bootloader is no longer active; the application is now running instead.

Maryem.