Preventing Automatic Power Down

4/19/2010

You can override the automatic suspend that occurs when no user input has occurred for a period of time. To prevent automatic power down, call the SystemIdleTimerReset function more frequently than the minimum suspend timeout values.

On Windows Mobile Classic and Windows Mobile Professional, the minimum timeout value can be retrieved from the registry. For more information, see SystemIdleTimerReset.

For Windows Mobile Standard, the minimum timeout values can be retrieved from the metabase by using the following xml:

<wap-provisioningdoc>
    <characteristic type="DeviceInformation">
            <parm-query name="[name]"/>
    </characteristic>
</wap-provisioningdoc>

Where "[name]" is either "BacklightBatteryTimeout" or "BacklightACTimeout"

To conserve resources, only call SystemIdleTimerReset as often as absolutely necessary. Calling SystemIdleTimerReset too often will reduce battery life due to excessive CPU use.

See Also

Concepts

Handling Application Hibernation
Handling Low Memory States
How to: Determine Available Memory
How to: Determine Battery Status
How to: Program an Application for Windows Mobile Standard to Turn the Backlight On or Off
How to: Suspend the Device
Managing Variables, Stacks, and Heaps on Windows Mobile Devices
Getting Memory Status and Processor Information
System Out of Memory Dialog Box

Other Resources

Memory and Power Management