User Manual

8 GPS/GNSS Synchronization Guide
This guide will explain how to physically connect a GPS to your Ouster sensor and synchronize the
Ouster sensor timestamp to an NMEA sentence.
8.1 Setting up your GPS/GNSS
It is important to ensure you have configured your GPS according to the manufacturer’s specifications.
The Ouster sensor accepts the following:
NMEA sentence type: GPRMC only (future support for other sentence types)
Baud Rates: 9600 or 115200
Polarity: Normal or Reversed (ACTIVE_HIGH
1
or
ACTIVE_LOW
2
)
Voltage: 3.3 - 15 V logic with a minimum drive current of 5 mA.
If your GPS can’t meet these minimums you will need to buffer the voltage with an additional
circuit. Details in the Digital IO section of the Ouster Hardware User Manual.
Note: Once you have configured your GPS, it is good practice to verify the signals using an oscil-
loscope. This will ensure you have the correct baud rate, polarity, voltage, and message type being
output.
→
1 Low to high edge as critical timing event
2 High to low edge as critical timing event
8.2 Connecting the Hardware
The next step to successfully connecting your GPS is ensuring that you have connected the outputs
from your GPS to the correct inputs of the sensor.
For lab applications where you will use the Interface Box, it is recommended to use terminated jumper
wires like these to ensure a solid connection.
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