PwmIn.cpp

00001 //mbed Microcontroller Library
00002 //Pulse Width Modulation Input Interface
00003 //Copyright 2010
00004 //Thomas Hamilton
00005 
00006 #include "PwmIn.h"
00007 
00008 PwmIn::PwmIn(PinName pwi) : InterruptIn(pwi), PeriodMeasurement(0), PulseWidthMeasurement(1)
00009 {
00010     mode(PullDown);
00011     rise(this, &PwmIn::PulseStart);
00012     fall(this, &PwmIn::PulseStop);
00013     start();
00014 }
00015 
00016 float PwmIn::read()
00017 {
00018     return (float)PulseWidthMeasurement / PeriodMeasurement;
00019 }
00020 
00021 float PwmIn::period()
00022 {
00023     return (float)PeriodMeasurement / 1000000;
00024 }
00025 
00026 int PwmIn::period_ms()
00027 {
00028     return PeriodMeasurement / 1000;
00029 }
00030 
00031 int PwmIn::period_us()
00032 {
00033     return PeriodMeasurement;
00034 }
00035 
00036 float PwmIn::pulsewidth()
00037 {
00038     return (float)PulseWidthMeasurement / 1000000;
00039 }
00040 
00041 int PwmIn::pulsewidth_ms()
00042 {
00043     return PulseWidthMeasurement / 1000;
00044 }
00045 
00046 int PwmIn::pulsewidth_us()
00047 {
00048     return PulseWidthMeasurement;
00049 }
00050 
00051 void PwmIn::PulseStart()
00052 {
00053     PeriodMeasurement = read_us();
00054     reset();
00055 }
00056 
00057 void PwmIn::PulseStop()
00058 {
00059     PulseWidthMeasurement = read_us();
00060 }