Specifications

WA_DEV_FEX20_PTS_003 Rev 002 May 26, 2010 18
6. AT Commands for the Battery
Accessory
There are three different methods for monitoring the battery status. The user can:
 check the presence of DC-IN charging
 check the presence of USB charging
 check how much charge is available in the battery accessory
6.1. DC-IN Status
GPIO1 is an internal signal of the Fastrack Xtend and is dedicated for DC-IN status monitoring.
GPIO1 can be controlled by Fastrack Xtend users using AT Commands.
When the power is applied on DC-IN, GPIO1 is pulled down to logic 0, and when the power is
disconnected on DC-IN, it is pulled up to logic 1.
To monitor the GPIO1 level, use a communication software such as HyperTerminal and enter the
following AT Commands:
 To set GPIO1 as input, enter AT+WIOM=1,”GPIO1”,0
Note: GPIO1 needs to be set as an input initially.
 To read GPIO1 status, enter AT+WIOR=”GPIO1”
6.2. USB Power Status
The standard USB interface provides a +5V power supply signal, which can be used to charge the
battery accessory. This source is limited since the default mode of the USB power cannot provide
more than 100mA. Consequently, the Fastrack Xtend cannot be used in Communication mode with
the USB source unless a charged battery is connected. Likewise, the USB power input has the
capability to charge the battery with a maximum current of 100mA.
Note: The USB power may provide more than 100mA provided the mode of the USB power is changed to
something other than the default mode.
USB detection is done via modem software. To enable USB communications between the Fastrack
Xtend and the application, use the UART1 connection and a communication software such as
HyperTerminal and enter the AT Command AT+WMFM=0,1,3.
Note: Sending the AT Command AT+WMFM=0,1,3 is only done via UART1.