1Pps Output; Gnss Fix Output; Odometer Input - Advanced Navigation Spatial Dual Reference Manual

Function
Wheel Encoder Phase B
Event 1 Input
Event 2 Input
GNSS Receiver Passthrough
TSS1 Output
Simrad 1000 Output
Simrad 3000 Output
Serial Port Passthrough
Gimbal Encoder Phase A
Gimbal Encoder Phase B
Odometer Direction, Forward Low
Odometer Direction, Forward High
Table 20: GPIO pin functions
12.3.1

1PPS Output

In this function, the pin is normally low and pulses high for 50 milliseconds to signal
the precise second. The 1PPS line starts pulsing approximately 100 milliseconds after
power up and always fires irrespective of whether Spatial Dual has accurate time or
not. It is important to note that when Spatial Dual acquires time corrections from it's
GNSS receiver, the 1PPS signal may fire at an interval of less than 1 second. This
typically only occurs the first time the GNSS receiver obtains a fix after startup. The
time initialised status flag can be used to determine whether the time and 1PPS line is
accurate or not.
12.3.2

GNSS Fix Output

In this function, the pin is low when there is no GNSS fix or a 2D fix and high when
there is a 3D, SBAS, Differential or RTK GNSS fix.
12.3.3

Odometer Input

This function is designed for low resolution vehicle speed sensors and odometers. It
expects a normally low input with a high state for the trigger. If the pulse length is
more than 0.1 metres this odometer input function should be used, if it is less than 0.1
metres the wheel speed sensor function should be used. Please contact Advanced
Navigation support for help integrating with your speed sensor.
Spatial Dual Reference Manual
Page 82 of 137
Version 2.3
12/04/2016
Type
Frequency Input
Digital Input
Digital Input
Serial
Serial Transmit
Serial Transmit
Serial Transmit
Serial
Frequency Input
Frequency Input
Digital Input
Digital Input
GPIOs Auxiliary
RS232
All
All
All
All All
1 Transmit
1 Transmit
1 Transmit
All All
All
All
All
All