cphidgetweightsensor.c

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#include "stdafx.h"
#include "cphidgetweightsensor.h"
#include "cusb.h"
#include "csocket.h"
#include "cthread.h"
#include <math.h>

// === Internal Functions === //

//clearVars - sets all device variables to unknown state
CPHIDGETCLEARVARS(WeightSensor)

        phid->Weight = PUNI_DBL;
        phid->lastweight = PUNK_DBL;
        phid->WeightChangeTrigger = PUNI_DBL;

        return EPHIDGET_OK;
}

//initAfterOpen - sets up the initial state of an object, reading in packets from the device if needed
//                                used during attach initialization - on every attach
CPHIDGETINIT(WeightSensor)
        TESTPTR(phid);

        //initialize triggers, set data arrays to unknown
        phid->Weight = PUNK_DBL;
        phid->lastweight = PUNK_DBL;
        phid->WeightChangeTrigger = 0.1;

        //issue one read
        CPhidget_read((CPhidgetHandle)phid);

        return EPHIDGET_OK;
}

//dataInput - parses device packets
CPHIDGETDATA(WeightSensor)
        double Weight = 0;

        if (length<0) return EPHIDGET_INVALIDARG;
        TESTPTR(phid);
        TESTPTR(buffer);
        
        //Parse device packets - store data locally
        switch(phid->phid.deviceIDSpec)
        {
                case PHIDID_WEIGHTSENSOR:
                        Weight = (((double)((unsigned short)buffer[0]+((unsigned short)buffer[1]<<8))) / 100.0 ) - 40.0;
                        Weight = round_double(Weight, 2);
                        break;
                default:
                        return EPHIDGET_UNEXPECTED;
        }

        //store to structure
        phid->Weight = Weight;

        //send out any events that exceed or match the trigger
        if (fabs(phid->Weight - phid->lastweight) >= phid->WeightChangeTrigger || phid->lastweight == PUNK_DBL)
        {
                FIRE(WeightChange, phid->Weight);
                phid->lastweight = phid->Weight;
        }
        return EPHIDGET_OK;
}

//eventsAfterOpen - sends out an event for all valid data, used during attach initialization
CPHIDGETINITEVENTS(WeightSensor)
        if (phid->Weight != PUNK_DBL)
        {
                FIRE(WeightChange, phid->Weight);
                phid->lastweight = phid->Weight;
        }
        return EPHIDGET_OK;
}

//getPacket - not used for WeightSensor
CGETPACKET(WeightSensor)
        return EPHIDGET_UNEXPECTED;
}

// === Exported Functions === //

//create and initialize a device structure
CCREATE(WeightSensor, PHIDCLASS_WEIGHTSENSOR)

//event setup functions
CFHANDLE(WeightSensor, WeightChange, double)

CGET(WeightSensor,Weight,double)
        TESTPTRS(phid,pVal) 
        TESTDEVICETYPE(PHIDCLASS_WEIGHTSENSOR)
        TESTATTACHED
        TESTMASGN(Weight, PUNK_DBL)
        MASGN(Weight)
}

CGET(WeightSensor,WeightChangeTrigger,double)
        TESTPTRS(phid,pVal) 
        TESTDEVICETYPE(PHIDCLASS_WEIGHTSENSOR)
        TESTATTACHED
        TESTMASGN(WeightChangeTrigger, PUNK_DBL)
        MASGN(WeightChangeTrigger)
}
CSET(WeightSensor,WeightChangeTrigger,double)
        TESTPTR(phid) 
        TESTDEVICETYPE(PHIDCLASS_WEIGHTSENSOR)
        TESTATTACHED
        TESTRANGE(0, 300)
        if(CPhidget_statusFlagIsSet(phid->phid.status, PHIDGET_REMOTE_FLAG))
                ADDNETWORKKEY(Trigger, "%lE", WeightChangeTrigger);
        else
                phid->WeightChangeTrigger = newVal;
        return EPHIDGET_OK;
}