Clark Scheff / Ping

Library for interfacing with the Parallax Ping))) sensor.

Dependencies:   FPointer

ping.cpp@5:cbe07c09c64c, 2014-07-29 (annotated)

Committer:
d34d
Date:
Tue Jul 29 02:34:02 2014 +0000
Revision:
5:cbe07c09c64c
Parent:
3:0c337c262d84 
Add user defined delay between continuous readings.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
d34d 0:99ee7c741e9d 1 #include "ping.h"
d34d 0:99ee7c741e9d 2
d34d 3:0c337c262d84 3 Ping::Ping(PinName signalPin) : mSignalIo(signalPin), mEvent(signalPin),
d34d 5:cbe07c09c64c 4 mBusy(0), mValid(0), mContinuous(0),
d34d 5:cbe07c09c64c 5 mDelayBetweenReadings(DEFAULT_MEASUREMENT_DELAY_US), mTimer(), mRawReading(0) {
d34d 0:99ee7c741e9d 6 mEvent.rise(this, &Ping::start);
d34d 0:99ee7c741e9d 7 mEvent.fall(this, &Ping::stop);
d34d 0:99ee7c741e9d 8 }
d34d 0:99ee7c741e9d 9
d34d 0:99ee7c741e9d 10 bool Ping::startReading() {
d34d 0:99ee7c741e9d 11 return this->startReading(false);
d34d 0:99ee7c741e9d 12 }
d34d 0:99ee7c741e9d 13
d34d 0:99ee7c741e9d 14 bool Ping::startReading(bool continuous) {
d34d 0:99ee7c741e9d 15 mContinuous = continuous;
d34d 0:99ee7c741e9d 16 if (mBusy) return false;
d34d 0:99ee7c741e9d 17
d34d 0:99ee7c741e9d 18 mSignalIo.output();
d34d 3:0c337c262d84 19 mSignalIo.write(0);
d34d 3:0c337c262d84 20 wait_us(3);
d34d 3:0c337c262d84 21 mSignalIo.write(1);
d34d 3:0c337c262d84 22 wait_us(3);
d34d 3:0c337c262d84 23 mSignalIo.write(0);
d34d 0:99ee7c741e9d 24 mSignalIo.input();
d34d 0:99ee7c741e9d 25
d34d 0:99ee7c741e9d 26 return true;
d34d 0:99ee7c741e9d 27 }
d34d 0:99ee7c741e9d 28
d34d 0:99ee7c741e9d 29 void Ping::start() {
d34d 0:99ee7c741e9d 30 mBusy = true;
d34d 0:99ee7c741e9d 31 mValid = false;
d34d 3:0c337c262d84 32 mTimer.reset();
d34d 0:99ee7c741e9d 33 mTimer.start();
d34d 0:99ee7c741e9d 34 }
d34d 0:99ee7c741e9d 35
d34d 0:99ee7c741e9d 36 void Ping::stop() {
d34d 0:99ee7c741e9d 37 mBusy = false;
d34d 0:99ee7c741e9d 38 mValid = true;
d34d 0:99ee7c741e9d 39 // The time it takes is for a round trip. We divide by two to get the time for one way.
d34d 3:0c337c262d84 40 mRawReading = mTimer.read_us() >> 1;
d34d 0:99ee7c741e9d 41 mTimer.stop();
d34d 0:99ee7c741e9d 42 mCallback.call(mRawReading);
d34d 5:cbe07c09c64c 43 if (mContinuous) mMeasureDelayTicker.attach_us(this, &Ping::nextMeasurement, mDelayBetweenReadings);
d34d 1:72fbcb01291d 44 }
d34d 1:72fbcb01291d 45
d34d 1:72fbcb01291d 46 void Ping::nextMeasurement() {
d34d 1:72fbcb01291d 47 mMeasureDelayTicker.detach();
d34d 1:72fbcb01291d 48 this->startReading(mContinuous);
d34d 0:99ee7c741e9d 49 }