Freq calculations using counters and interrupt

Dependencies:   FastPWM PwmIn USBDevice mbed

Revision:
0:6d4f91decc4f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PwmIn.lib	Thu Nov 13 13:26:08 2014 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/simon/code/PwmIn/#6d68eb9b6bbb