Rob Dobson / RdGasUseMonitor

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Dependencies:   EthernetInterfacePlusHostname NTPClient Onewire RdWebServer SDFileSystem-RTOS mbed-rtos mbed-src

PulsePin.cpp@22:14b4060dd027, 2015-10-16 (annotated)

Committer:
Bobty
Date:
Fri Oct 16 08:42:13 2015 +0000
Revision:
22:14b4060dd027
Parent:
10:72eb217def1f 
Re-enabled web folder view on server

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Bobty 2:6bfef0839102 1 // Handles a pin that has a slow pulse applied
Bobty 2:6bfef0839102 2 // Written for a gas meter monitor
Bobty 10:72eb217def1f 3 // Rob Dobson, 2015
Bobty 2:6bfef0839102 4
Bobty 2:6bfef0839102 5 #include "PulsePin.h"
Bobty 2:6bfef0839102 6
Bobty 4:0d3a207680b0 7 PulsePin::PulsePin(DigitalIn& pin, bool detectRisingEdge, int waitForPinStabilisationMs) :
Bobty 2:6bfef0839102 8 _pin(pin)
Bobty 2:6bfef0839102 9 {
Bobty 4:0d3a207680b0 10 _detectRisingEdge = detectRisingEdge;
Bobty 2:6bfef0839102 11 _waitForPinStabilisationMs = waitForPinStabilisationMs;
Bobty 2:6bfef0839102 12 _pinTimer.start();
Bobty 2:6bfef0839102 13 _curPinState = _pin;
Bobty 2:6bfef0839102 14 _lastStableTimeMs = _pinTimer.read_ms();
Bobty 2:6bfef0839102 15 _firstEdgeDetected = false;
Bobty 2:6bfef0839102 16 _timeBetweenEdgesMs = 0;
Bobty 5:5bccf48799d4 17 _pulseCount = 0;
Bobty 5:5bccf48799d4 18 _pinTimerMinutes = 0;
Bobty 2:6bfef0839102 19 }
Bobty 2:6bfef0839102 20
Bobty 2:6bfef0839102 21 bool PulsePin::Service()
Bobty 2:6bfef0839102 22 {
Bobty 2:6bfef0839102 23 // Check time since last edge - looking for stability
Bobty 2:6bfef0839102 24 int timeNowMs = _pinTimer.read_ms();
Bobty 5:5bccf48799d4 25
Bobty 5:5bccf48799d4 26 // Check if over 1 minute (as the timer wraps around after 30 mins)
Bobty 5:5bccf48799d4 27 if (timeNowMs > 60000)
Bobty 5:5bccf48799d4 28 {
Bobty 5:5bccf48799d4 29 _pinTimerMinutes++;
Bobty 5:5bccf48799d4 30 _pinTimer.reset();
Bobty 5:5bccf48799d4 31 timeNowMs -= 60000;
Bobty 5:5bccf48799d4 32 }
Bobty 5:5bccf48799d4 33
Bobty 5:5bccf48799d4 34 // Get the real time elapsed (still wraps but now only after about 500 hours)
Bobty 5:5bccf48799d4 35 timeNowMs = _pinTimerMinutes*60000 + timeNowMs;
Bobty 5:5bccf48799d4 36
Bobty 5:5bccf48799d4 37 // Check for pin stabilization
Bobty 2:6bfef0839102 38 if (timeNowMs < _lastStableTimeMs + _waitForPinStabilisationMs)
Bobty 2:6bfef0839102 39 return false;
Bobty 2:6bfef0839102 40
Bobty 2:6bfef0839102 41 // Check for a change of state
Bobty 2:6bfef0839102 42 bool pinState = _pin;
Bobty 2:6bfef0839102 43 if (pinState == _curPinState)
Bobty 2:6bfef0839102 44 return false;
Bobty 2:6bfef0839102 45
Bobty 2:6bfef0839102 46 _curPinState = pinState;
Bobty 2:6bfef0839102 47 _lastStableTimeMs = timeNowMs;
Bobty 2:6bfef0839102 48
Bobty 2:6bfef0839102 49 // Check if this is the direction of edge we're looking for
Bobty 4:0d3a207680b0 50 if (pinState != _detectRisingEdge)
Bobty 2:6bfef0839102 51 return false;
Bobty 2:6bfef0839102 52
Bobty 2:6bfef0839102 53 // Reset the timer to avoid wrap around problems
Bobty 2:6bfef0839102 54 bool firstEdgeDetected = _firstEdgeDetected;
Bobty 5:5bccf48799d4 55 _pinTimerMinutes = 0;
Bobty 2:6bfef0839102 56 _pinTimer.reset();
Bobty 2:6bfef0839102 57 _firstEdgeDetected = true;
Bobty 2:6bfef0839102 58 _lastStableTimeMs = 0;
Bobty 2:6bfef0839102 59
Bobty 2:6bfef0839102 60 // Check if this should be returned
Bobty 2:6bfef0839102 61 if (!firstEdgeDetected)
Bobty 2:6bfef0839102 62 return false;
Bobty 2:6bfef0839102 63 _timeBetweenEdgesMs = timeNowMs;
Bobty 5:5bccf48799d4 64 _pulseCount++;
Bobty 2:6bfef0839102 65 return true;
Bobty 2:6bfef0839102 66 }
Bobty 2:6bfef0839102 67
Bobty 5:5bccf48799d4 68 int PulsePin::GetPulseRateMs()
Bobty 2:6bfef0839102 69 {
Bobty 2:6bfef0839102 70 return _timeBetweenEdgesMs;
Bobty 2:6bfef0839102 71 }
Bobty 5:5bccf48799d4 72
Bobty 5:5bccf48799d4 73 int PulsePin::GetPulseCount()
Bobty 5:5bccf48799d4 74 {
Bobty 5:5bccf48799d4 75 return _pulseCount;
Bobty 5:5bccf48799d4 76 }
Bobty 5:5bccf48799d4 77
Bobty 5:5bccf48799d4 78 void PulsePin::SetPulseCount(int pulseCount)
Bobty 5:5bccf48799d4 79 {
Bobty 5:5bccf48799d4 80 _pulseCount = pulseCount;
Bobty 5:5bccf48799d4 81 }