Power +API Tutorial

Introduction

Power API methods can be used by constructing +an instance of CHWRMPower and calling +its functions. However, to use its full functionality write a class which +implements one or more of the observer interfaces described in the following +table. Then, construct an instance of CHWRMPower and +provide it with pointers to observers.

+ + + +Interface +Notification +Method to override + + + + +

MHWRMBatteryPowerObserver

Average battery voltage and current consumption

PowerMeasurement

+ + +

MHWRMBatteryChargingStatusObserver

Charging status

ChargingStatusChange

+ + +

MHWRMBatteryChargingCurrentObserver

Average charging current

AverageChargingCurrentChange

+ + +

MHWRMBatteryFullChargingTimeObserver

Remaining charging time

BatteryFullChargingTimeChange

+ + + +

For example, if the application requires periodic measurements +of average battery voltage and current consumption, it must implement MHWRMBatteryPowerObserver and instantiate a CHWRMPower object using the CHWRMPower::NewL(NULL, +MHWRMBatteryPowerObserver *) method.

Note: The battery +charging observers cannot be passed to CHWRMPower using +a NewL() function. Call the dedicated +function, CHRMPower::SetBatteryChargingObserver().

Procedure

Derive +a class from one or more of the above interfaces.
Implement +the appropriate observer functions.
Create +a power client using CHWRMPower::NewL() or NewLC().
You +can retrieve the battery voltage or consumption information.
Call CHRMPower::SetBatteryChargingObserver(), if +necessary.
Start +receiving notification using the appropriate start function(s).
Stop +receiving notification using the appropriate stop function(s).

Note: If the notification period exceeds the maximum reporting +period, set when the HWRM server starts, notification is cancelled.