Diff: Handlers/GroveDht22.cpp

Revision:

0:2df78a4443cd

diff -r 000000000000 -r 2df78a4443cd Handlers/GroveDht22.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Handlers/GroveDht22.cpp	Sun Apr 10 15:47:33 2016 +1000
@@ -0,0 +1,121 @@
+#include "GroveDht22.h"
+#include "measurementhandler.h"
+
+#define GROVE_NUM_RETRIES 10        // number of retries for reading sensor
+
+DigitalOut grovePwr(P1_3);          // if anything else is interfaced to uart/adc/i2c connectors, this will have to change, as they share this enable line
+
+GroveDht22::GroveDht22(MeasurementHandler *_measure, MyTimers * _timer) : AbstractHandler(_timer), m_measure(_measure)
+{
+    // initialise class variables
+    mode            = dht_StartTurnOff;
+    _lastCelcius    = 0.0f;
+    _lastHumidity   = 0.0f;
+    _lastDewpoint   = 0.0f;
+    _lastError      = ERROR_NONE;
+    _retries        = 0;
+    _newInfo        = 0;
+
+    m_sensor = new DHT(P1_14,SEN51035P);        // Use the SEN51035P sensor
+}
+
+GroveDht22::~GroveDht22()
+{
+    delete m_sensor;
+}
+
+void GroveDht22::run()
+{
+    switch(mode)
+    {
+    case dht_StartTurnOff:
+        powerOn(false);
+        m_timer->SetTimer(MyTimers::tmr_GroveMeasure, 1000);     // leave off for 1 second
+        mode = dht_StartTurnOffWait;
+        break;
+
+    case dht_StartTurnOffWait:
+        if (!m_timer->GetTimer(MyTimers::tmr_GroveMeasure))      // wait until timer has elapsed
+            mode = dht_StartTurnOn;
+        // else come back here
+        break;
+
+    case dht_StartTurnOn:
+        powerOn(true);
+        m_timer->SetTimer(MyTimers::tmr_GroveMeasure, 1000);     // wait one second for sensor to settle
+        mode = dht_StartTurnOnWait;
+        break;
+
+    case dht_StartTurnOnWait:
+        if (!m_timer->GetTimer(MyTimers::tmr_GroveMeasure))      // wait until timer has elapsed
+            mode = dht_TakeMeasurement;
+        // else come back here
+        break;
+
+    case dht_TakeMeasurement:
+        _lastError = (eError)m_sensor->readData();     // take the measurement (todo: see if nonblocking is available)
+        if (_lastError == ERROR_NONE)
+        {
+            _retries = 0;                   // reset retries as measurement was successful
+            _lastCelcius = m_sensor->ReadTemperature(CELCIUS);
+            _lastHumidity = m_sensor->ReadHumidity();
+            _lastDewpoint = m_sensor->CalcdewPoint(_lastCelcius, _lastHumidity);
+            m_timer->SetTimer(MyTimers::tmr_GroveMeasure, 3000); // wait three seconds
+            
+            // add the date time
+            time_t _time = time(NULL); // get the seconds since dawn of time
+            Dht22Result data = {_time, _lastCelcius, _lastHumidity, _lastDewpoint};
+            m_measure->setRequest(MeasurementHandler::measreq_DhtResult, (void*)&data);
+            mode = dht_WaitMeasurement;
+        }
+        else
+        {
+            _retries++;     // there was an error. See if we have reached critical retries
+            if (_retries >= GROVE_NUM_RETRIES)
+            {
+                _retries = 0;
+                mode = dht_StartTurnOff; // restart the sensor
+            }
+            else
+            {
+                // haven't reach critical retries yet, so try again, after waiting
+                m_timer->SetTimer(MyTimers::tmr_GroveMeasure, 3000); // wait three seconds
+                mode = dht_WaitMeasurement;
+            }
+            int sendData = (int)_lastError; // just to make sure nothing funny happens with the enum
+            m_measure->setRequest(MeasurementHandler::measreq_DhtError, (int*)&sendData);
+        }
+        _newInfo = 1;
+        break;
+
+    case dht_WaitMeasurement:
+        if (!m_timer->GetTimer(MyTimers::tmr_GroveMeasure))  // if timer elapsed
+            mode = dht_TakeMeasurement;
+        // else come back here
+        break;
+
+    }
+}
+
+void GroveDht22::setRequest(int request, void *data)
+{
+    // no requests (yet)
+}
+
+// check if there is new information and reset the flag once the check occurs
+unsigned char GroveDht22::newInfo()
+{
+    unsigned char retval = _newInfo;
+    _newInfo = 0;
+    return retval;
+}
+
+// turn the enable pin for the peripheral plugins on the Arch GPRS v2
+// it is active low and acts on Q1
+void GroveDht22::powerOn(unsigned char ON)
+{
+    if (ON)
+        grovePwr = 0;   // active low, will turn power on
+    else
+        grovePwr = 1;   // will turn power off
+}