IDP 800 Terminal Series - Hardware Guide
© SkyWave Proprietary 29 T209, Version 01
Figure 15 Accelerometer Axis
The accelerometer is very important for low power terminals when it is critical to save
power when stationary, while quickly detecting when motion has started. In powered
terminals where low power is not critical, GPS can be polled to detect motion. However,
for low power applications like the IDP-800, frequent GPS fixes can dominate the power
budget. To reduce power budget effects of GPS fixes, an accelerometer can be used to
trigger a GPS fix to detect if motion occurred.
The accelerometer thresholds to detect motion vary depending on the environment. In
order to avoid, false motion detects, extensive testing is required to ensure that adequate
acceleration magnitude thresholds and time durations are used.
Table 22
Accelerometer Specification
Parameter
Condition
Min
Typ
Max
Units
Resolution
2 g
-
3.91
-
mG
Acceleration
Range
software selectable
-
±2
-
g
software selectable
-
±4
-
g
software selectable
-
±8
-
g
software selectable
-
±16
-
g
Bandwidth
Filtering
Selectable via digital interface
8
-
1000
Hz
Sensitivity
2 g
-
256
-
LSB/g
4 g
-
128
-
LSB/g
8 g
-
64
-
LSB/g
16 g
-
32
-
LSB/g