Kenji Arai
Only for mbed LPC1768, mbed LPC1114FN28, Nucleo-F401 and Nucleo-F411. No way to change pin assign.
Dependencies: freq_counter TextLCD
Fork of
5MHzOSC
by 
fuyuno sakura
Please refer following page.
http://developer.mbed.org/users/kenjiArai/notebook/simple-frequency-counter/
/users/kenjiArai/notebook/frequency-counters/