My Arduino don't show port but is working

Question

I have some problem with Arduino uno and asked here, so I have tried to work by my STM32F103C8 as alternative board, and solved my problem by this question:

Arduino Port Not detected and can not run it as root

But now I as seeing that the Arduino port again is not acceptable but I can upload the codes into the STM32F103C8 board, so I asked why this happen ?

enter image description here Note : I have seen this post which the STm32F103C8 board have some port on Arduino IDE (as you can see below ):

enter image description here

Update:

I have seen The below post about the same problem as you can see below:

Can't open serial monitor using ST Link and STM32F103C8

But, based of the last part of above post,which is shown below, I don't get have could i have enable the serial port connection for the STM32f103C8 Board:

I did everything as it was described in tutorial, flashing bootloader was succes, everything went ok, but windows still can't recognize it. I am thinking that maybe it is problem with that resistor and maybe i have to mod it... I think I will be sticking to ST-Link for uploading codes and USB-UART for serial. But thanks for help

And one more question, can you tell me how to reset my Blue Pill to factory bootloader (how to delete stm32 bootloader that I installed)

Thank.

• Juraj: it doesn't work. only the tool reports a wrong result
• Nathan Jiang: Is there a default that it tries to transmit the sketch to if no ports are selected?

Answer 1

The STM32F103C8 has a native USB interface. You will only ever see a CDC/ACM (USB UART emulation) interface if you actively run code that implements a CDC/ACM interface.

The bootloader is separate to your code. I don't know what protocol the bootloader for your board uses, but it may not even have a CDC/ACM interface to it.

In short: it doesn't have a port because you haven't programmed it to have a port, and the code uploading doesn't use a port, so doesn't care.

• Soheil Paper: Thanks, but was is the means of /dev/2 on the Arduino IDE result which shown here?!
• Majenko: It'll be something specific to dfu-util. Btw, dfu is a custom protocol that has no serial or anything like it.
• Soheil Paper: So You are saying, For enabling the port option in Arduino IDE, I must burn some boatloader to the STM32f103c8 board by Arduino IDE or other software?
• Majenko: No, you just write a sketch that uses the usb serial.