Specifications

WA_DEV_FEX20_PTS_003 Rev 002 May 26, 2010 20
Battery Accessory Product Technical
Specification
AT Commands for the Battery
Accessory
6.3. Battery Level Status
ADC1 is an internal signal of the Fastrack Xtend and is dedicated for measuring the battery accessory
voltage. From the ADC1value, a specific conversion is necessary to get the battery voltage.
The formula of the battery level to ADC1 reading (expressed in mV) is detailed below:
Battery voltage (Vbat) = 3.212 x ADC1 reading
For example, if ADC1 reading by AT command is 1218, then Vbat level = 3.212 x 1218 = 3912mV.
To monitor the battery level status, use a communication software such as HyperTerminal and enter
the following AT Command:
AT+ADC?
6.4. Battery Cell Connection Anomaly
It is possible to detect if the battery cell is not properly connected inside the battery accessory.
There are two different readings to identify this anomaly as described below.
 If DC-IN is used, ADC1 reads 5V steady on the battery terminal.
 If USB is used, ADC1 reads a pulse-shaped voltage waveform on the battery terminal (due to
the USB current limitation which is 100mA). Consequently, the voltage measured is not
stable. Refer to the following figure.
Figure 11. ADC1 Reading Using USB
ADC1 Reading