On_Off Control Input - Fibocom GTS-4E-00 Hardware Integration Manual


Optional Dead Reckoning sensors (e.g. 3-D Accelerometer)

Optional connectivity to EEPROM for Client Generated Extended Ephemeris (CGEE) data storage

Optional ROM patch code storage to EEPROM and upload to IT430
.
The accelerometer MEMS sensor provides stationary detection, which allows to reduce the position
spread when stationary with weak GPS signals e.g. indoors. Other features will follow like Point & Tell,
i.e. attitude (heading) information based on 3-D compass (contact Fastrax support for details). When
MEMS sensor is used connect also the sensor's INT output to IT430's EIT input. The bus signals
require external pull up resistors 2.2kohm on both signals. Connect both signals to GND (or pull up)
when not used.
DR I²C interface supports:

Common sensor formats (Kionix, KXTF9-4100 device)

Common EEPROM data formats (STMicroelectronics, M24M01, 1 Mbit device)

Typical data lengths (command + in/data out) of several bytes

Standard I²C bus maximum data rate 400kbps

Minimum data rate 100kbps
2.2.4

ON_OFF control input

The ON_OFF control input must be used by the host to wakeup the module after first power up and to
control the receiver activity between Normal and Hibernate states and also to generate interrupt in
Push-to-Fix and SiRFAware modes of operation.
The module will boot to Hibernate state after power up. First ON_OFF interrupt wakes up the module
for Normal (Navigation) operation. Consequent ON_OFF interrupts switch the operation mode between
Hibernate and Navigation modes.
The ON_OFF interrupt is generated by rising edge of a low-high-low pulse, which should be longer than
90us and less than 1s (suggestion is abt. 100ms pulse length). Do not generate ON_OFF interrupts
less than 1 sec intervals. Especially take care that any multiple switch bounce pulses are filtered out.
During Hibernate state the I/O Keep Alive is still active, thus I/O signals keep respective states except
TX and RX signals, which are configured to high input impedance state.
GTS-4E GPS Module Hardware Integration Manual Page 10 of 22