Pulse consistency test using wait_us in a thread

Revision:
0:18409537564c
Child:
1:4dec185d33e9
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Sat Mar 30 06:37:35 2019 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#51d55508e8400b60af467005646c4e2164738d48