Arduino for STM32

Sorry, I'm new to this forum. Is there something to do to mark this topic as "Sorted"?

Hi,
Thanks everybody for your contributions, I really appreciate.
I got it!!
Thanks to fpiSTM 's link on how to change Serial pins at sketch level.
I added:

Serial.setRx(PA10);
Serial.setTx(PA9);

Before the Serial.begin, and now I can see the messages in the serial monitor.
By the way I made a ...

fpiSTM is correct

it is a bit surprising that they put a usb-uart (ch340n) at pa9 / pa10 which is in turn connected to usb, as normally stm32f103 has its own usb.
stm32f103mini_sch.jpg
in this case, you'd need to use the normal uart option for Serial in your sketch

and it use buttons instead ...

To program stm32f103c8t6 blue pill via uart you need to set boot0
and you need stm32cubeprogrammer (or some such programming util)
https://www.st.com/en/development-tools/stm32cubeprog.html
^^ this is from ST (you can consider that an official programming tool)

Isn't that exactly what he wrote ...

If you select the generic target, the default Serial pins are not PA9/PA10 but PA2/PA3:
https://github.com/stm32duino/Arduino_Core_STM32/blob/5a40f2d257379c4a6e1184b564c4f7d4fc43e7c6/variants/STM32F1xx/F103C8T_F103CB(T-U)/variant_generic.h#L140-L145

You can change it at sketch level using the setRx ...

To program stm32f103c8t6 blue pill via uart you need to set boot0
and you need stm32cubeprogrammer (or some such programming util)
https://www.st.com/en/development-tools/stm32cubeprog.html
^^ this is from ST (you can consider that an official programming tool)

and a google search leads to various ...

STM32F103 has a USB interface built-in. Those are PA11 and PA12 pins. But it does not have USB bootloader (called DFU by STM) so you cannot flash firmware using USB without software bootloader (like HID bootloader )

It looks like those jumpers (not resistors) are under CH340 and by default are not ...

Thanks for your answer, good point!
So for "USB support (if available)", it's on None
for "U(s)ART support", it's on "Enable (generic 'Serial')"
and for "USB speed (if available)", it's on "Low/Full speed"

I just made a try selecting "CDC (generic 'Serial' superseed U(s)UART)" for "USB support" but ...

What are your settings for UART and USB support in Arduino IDE ??

Hi,
I'm new to STM32 mcus. And to start with I got this mini STM32F103C8T6 CH340 from aliexpress:
(https://fr.aliexpress.com/item/1005006910706030.html)
There is a ch340 chip on it so you can directly flash the board by pluging the board on a usb port. Works great (see below settings in Arduino IDE ...