Symbol MC9000-K/S, Reference Manual

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Bluetooth 8-3
Introduction
Bluetooth-equipped devices can communicate without wires, using frequency-hopping spread
spectrum (FHSS) RF to transmit and receive data in the 2.4 GHz Industry Scientific and Medical (ISM)
band (802.15.1). Bluetooth wireless technology is specifically designed for short-range (30 feet/10
meters) communications and low power consumption.
Mobile computers with Bluetooth capabilities can exchange information (e.g., files, appointments
and tasks) with other Bluetooth enabled devices such as phones, printers, access points and other
mobile computers. In addition, a dial-up modem connection can be created between the Bluetooth
mobile computer and a Bluetooth enabled phone. The Bluetooth phone can then be used as a modem.
Symbol mobile computers with Bluetooth technology use the Microsoft Bluetooth stack. To program
Bluetooth within the mobile computer refer to the Microsoft Embedded Visual C++ help.
Turning the Bluetooth Radio Mode On and Off
Turn off the Bluetooth radio mode to save power or if entering an area with radio restrictions (e.g., an
airplane). When the mode is off, the mobile computer can not be seen or connected to by other
Bluetooth devices. Turn on the Bluetooth radio mode to exchange information with other Bluetooth
devices (within range). Communicate only with Bluetooth radios in close proximity.
To achieve the best battery life in mobile computers with multiple radios, turn off the radios that are
not being used. This can be accomplished via the DevicePowerNotify() API (refer to the
SMDK Help
File ), or via the 9000 Demo Control Panel application. (The 9000 Demo program can be obtained from
the Symbol Web site.)
There are no Power Management APIs to call for the Bluetooth radio. The Microsoft stack mode APIs
cause the Bluetooth radio power state to directly correspond to the stack mode. BthSet/GetMode()
APIs cause the correct radio power state based on the stack’s mode (e.g., Mode Off = Power Off). The
mobile computer’s User Interfaces for stack mode control both stack state and power state (see
Power Window - Wireless Tab on page 3-45 , Bluetooth Window - Mode Tab on page 8-5 and
Connectivity Dialog Box on page 8-5 ). A Bluetooth icon appears in the command bar at the bottom of
the screen (sys tray) to indicate that the Bluetooth radio is on. The Bluetooth icon disappears when
the radio is off. The Bluetooth icon is for display purposes only.
BthGetMode() should be monitored after resuming the mobile computer. It
can take approximately 30 seconds until the stack finishes initialization. It is
recommended that BthGetMode() is checked before performing a Bluetooth
related task to ensure that another process or application has not changed
the Bluetooth mode.