SXBlue II GPS Series Technical Reference Manual
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3. Advanced Operations
This chapter introduces the general operational features of the SXBlue II GPS and configuration
procedures.
3.1 Firmware Architecture
The software that runs the SXBlue II GPS is often referred to as firmware since it operates at a
low level. There are two types of firmware within the SXBlue II GPS for the on-board Digital
Signal Processor (DSP) and the ARM processor. Each of these types of firmware may be
upgraded by the end-user through the main serial port as new revisions become available.
The ARM processor of the SXBlue II GPS engine supports two simultaneous versions of
firmware. Only one of them is in operation at any given time. These two versions of firmware
may have different functionality, and are also referred to as applications. See section 3.3.2.1 for
a list of Applications.
The SXBlue II GPS and SXBlue II-B GPS currently ship with the SBAS (“WAAS”) application
installed as Application 1 and Auto-Dif as Application 2. The default differential input within
Application 1 is set to “WAAS” for the SXBlue II GPS and to “Beacon” for the SXBlue II-B GPS.
The Auto-Dif on Application 2 requires a subscription code for activation.
The SXBlue II-L GPS features the SBAS (“WAAS”) application installed as Application 1 and the
LBAND application as Application 2. The default application is the LBAND and the default
differential correction is also LBAND. When switching to Application 1, the default differential
correction source is “WAAS”.
The Local-Dif, -RTK, -Base applications can be added at a later time on either Application 1 or
Application 2 memory locations. Higher update rates outputs are not applications, but should
rather be considered as “activated” or “unlocked” features within the applications. Chapter 4
describes the $JAPP command used to change between the two SXBlue II GPS applications.
Within the WAAS application, there are four differential modes, being WAAS, BEACON,
external correction source via one of the communication PORTS and NONE. Chapter 4 also
describes the $JDIFF command used to change between the differential modes.
3.2 Communicating with the SXBlue II GPS
The SXBlue II GPS features three communication ports that may be configured independently
from each other (Bluetooth, Serial and USB). The ports may be configured for any mixture of
NMEA 0183, binary, and RTCM SC-104 data. The usual data output is limited to NMEA data
messages since these are industry standard. When sending commands to configure the SXBlue
II GPS, these ports are referred to as:
•
Port A (Bluetooth)
•
Port B (Serial)
•
Port C (USB)
