Y SI / lib_ClockCounter

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ClockCounter Class Reference
Public Member Functions

ClockCounter Class Reference

ClockCounter class Counts signal transitions on p30(CAP2.0) or p29(CAP2.1) for LPC1768 target. More...

#include <lib_ClockCounter.h>

Public Member Functions

 ClockCounter (PinName PIN_CAP2=p30, edgeDetection EDGE=RISING)
 Create an ClockCounter instance.
void setPin (PinName PIN_CAP2, edgeDetection EDGE=RISING)
 Select an ClockCounter instance.
void startCount (void)
 Start the signal transition count.
int stopCount (void)
 Stop and Get the signal transition count.
int getCount (int period=1000000)
 Get the signal transition count during period.
PinName getPin (void)
 Get the selected input PIN_CAP2 on started signal transition count.

Detailed Description

ClockCounter class Counts signal transitions on p30(CAP2.0) or p29(CAP2.1) for LPC1768 target.

Can detecte rising, falling or both signal edge. Return the signal edge count during a period in seconds. In theory (Shannon's theorem) input signal frequency can up to 48 MHz with 96 MHz CCLK. But only tested with frequencys up to 20 MHz and it work.

Definition at line 42 of file lib_ClockCounter.h.

Constructor & Destructor Documentation

ClockCounter ( PinName  PIN_CAP2 = p30,
edgeDetection  EDGE = RISING 
)

Create an ClockCounter instance.

Mbed Library Clock Counter Hardware pulse counter with TIMER2 (CAP2.0 or CAP2.1) on Mbed LPC1768.

Configure LPC1768 TIMER2 with capture input PIN_CAP2 and detecte transition EDGE.

Parameters:
PIN_CAP2can be p30(CAP2.0) or p29(CAP2.1), default is p30(CAP2.0).
EDGEcan be RISING, FALLING, BOTH, default is RISING.

Counts signal transitions on p30(CAP2.0) or p29(CAP2.1) for LPC1768 target. Can detecte rising, falling or both signal edge. Return the signal edge count during a period in seconds. In theory (Shannon's theorem) input signal frequency can up to 48 MHz with 96 MHz CCLK. But only tested with frequencys up to 20 MHz and it work.

Example : 

 #include "mbed.h"
 #include "lib_ClockCounter.h"

 Serial pc(USBTX, USBRX);
 ClockCounter Frequency;
 
 int main()
 {
     while(1) pc.printf("Frequency = %d Hz\r\n", Frequency.getCount());
 }

Definition at line 28 of file lib_ClockCounter.cpp.

Member Function Documentation

int getCount ( int  period = 1000000 )

Get the signal transition count during period.

Parameters:
perioddefault is 1000000 microsecond.

Definition at line 92 of file lib_ClockCounter.cpp.

PinName getPin ( void   )

Get the selected input PIN_CAP2 on started signal transition count.

Definition at line 102 of file lib_ClockCounter.cpp.

void setPin ( PinName  PIN_CAP2,
edgeDetection  EDGE = RISING 
)

Select an ClockCounter instance.

Configure LPC1768 TIMER2 with capture input PIN_CAP2 and detecte transition EDGE.

Parameters:
PIN_CAP2can be p30(CAP2.0) or p29(CAP2.1).
EDGEcan be RISING, FALLING, BOTH, default is RISING.

Definition at line 53 of file lib_ClockCounter.cpp.

void startCount ( void   )

Start the signal transition count.

Definition at line 77 of file lib_ClockCounter.cpp.

int stopCount ( void   )

Stop and Get the signal transition count.

Definition at line 84 of file lib_ClockCounter.cpp.

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