Using USBSerial on BLACKPILL board.

For more details click on the link below:

Import programBlackpill_Hello

Using low cost Blackpill (STM32F411CEU6) boards with mbed.

Revision:
0:2912fe6f7530
Child:
2:9625237e90fa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Sat Jan 30 11:18:14 2021 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#cf4f12a123c05fcae83fc56d76442015cb8a39e9