Blue Pill recognized in macOS, but no port available

[Amyspark]

Hey,

I was able to flash the bootloader to my blue pill (F103C8T6) using the st-flash utility. However, I cannot flash any sketches because macOS doesn't seem to detect a COM port in it (/dev/cu.*).
The only way to flash a sketch reliably is to switch to a Windows machine, use the CDC mode (#19) to flash a first sketch with USART serial enabled, and only then to switch the jumpers to BOOT0-0 and BOOT1-0.

If somehow I forget to keep USART enabled in macOS, the COM port disappears and I cannot flash anything again until I reflash the bootloader and a sketch in Windows.

[KenjutsuGH]

Hi,

I do not know if you managed to get this working, but this is what I do with each Blue Pill I want to load the bootloader on:

1. I flash the latest medium density bootloader .bin file to my BP using a serial adapter.

2. I then disconnect the serial adapter and completely remove power from the BP, and restore the BOOT jumpers

3. I reconnect the BP via USB

4. USB Prober now displays the following:
   

5. I start the Arduino IDE and create a new Blink sketch

6. I change the settings as follows:
   
   Note: There is no serial port available

7. I then upload the Blink sketch:

error, counldn't open [/dev/cu.wchusbserialfd12120]
+-----------------------------------------------------------------------+
|         HID-Flash v2.2.1 - STM32 HID Bootloader Flash Tool            |
|     (c)      2018 - Bruno Freitas       http://www.brunofreitas.com   |
|     (c) 2018-2019 - Vassilis Serasidis  https://www.serasidis.gr      |
|   Customized for STM32duino ecosystem   https://www.stm32duino.com    |
+-----------------------------------------------------------------------+

> Trying to open the [cu.wchusbserialfd12120]...
> Unable to open the [cu.wchusbserialfd12120]
> Searching for [1209:BEBA] device...
#
> [1209:BEBA] device is found !
> Sending <reset pages> command...
> Flashing firmware...
. 1024 Bytes
. 2048 Bytes
. 3072 Bytes
. 4096 Bytes
. 5120 Bytes
. 6144 Bytes
. 7168 Bytes
. 8192 Bytes
. 9216 Bytes
. 10240 Bytes
. 11264 Bytes
. 12288 Bytes
. 13312 Bytes
. 14336 Bytes
. 15360 Bytes
. 16384 Bytes
. 17408 Bytes
. 18432 Bytes
. 19456 Bytes
. 20480 Bytes
. 21504 Bytes

> Done!
> Sending <reboot mcu> command...
> Searching for [cu.wchusbserialfd12120] ...
error, counldn't open [/dev/cu.wchusbserialfd12120]
error, counldn't open [/dev/cu.wchusbserialfd12120]
error, counldn't open [/dev/cu.wchusbserialfd12120]
error, counldn't open [/dev/cu.wchusbserialfd12120]
error, counldn't open [/dev/cu.wchusbserialfd12120]
> Finish

8. USB Proper now displays:
   
   and the Blink sketch is successfully executing
9. Back in the Arduino IDE, the correct serial port is now available:
   
10. When I now modify and upload the Blink sketch again:

+-----------------------------------------------------------------------+
|         HID-Flash v2.2.1 - STM32 HID Bootloader Flash Tool            |
|     (c)      2018 - Bruno Freitas       http://www.brunofreitas.com   |
|     (c) 2018-2019 - Vassilis Serasidis  https://www.serasidis.gr      |
|   Customized for STM32duino ecosystem   https://www.stm32duino.com    |
+-----------------------------------------------------------------------+

> Trying to open the [cu.usbmodemFD1221]...
> Toggling DTR...
> Searching for [1209:BEBA] device...
##
> [1209:BEBA] device is found !
> Sending <reset pages> command...
> Flashing firmware...
. 1024 Bytes
. 2048 Bytes
. 3072 Bytes
. 4096 Bytes
. 5120 Bytes
. 6144 Bytes
. 7168 Bytes
. 8192 Bytes
. 9216 Bytes
. 10240 Bytes
. 11264 Bytes
. 12288 Bytes
. 13312 Bytes
. 14336 Bytes
. 15360 Bytes
. 16384 Bytes
. 17408 Bytes
. 18432 Bytes
. 19456 Bytes
. 20480 Bytes
. 21504 Bytes

> Done!
> Sending <reboot mcu> command...
> Searching for [cu.usbmodemFD1221] ...
error, counldn't open [/dev/cu.usbmodemFD1221]
> [cu.usbmodemFD1221] is found !
> Finish