virtual COM and led blink test

Revision:
0:1cdce12c0462
diff -r 000000000000 -r 1cdce12c0462 .gitignore
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.gitignore	Tue Jun 08 13:05:27 2021 +0000
@@ -0,0 +1,4 @@
+.build
+.mbed
+projectfiles
+*.py*