AC530 Fastrax, AC530 Datasheet - Page 11

• Manufacturer Part Number: AC530
• Description: GPS Development Tools Application Board for UC530
• Manufacturer: Fastrax

Specifications of AC530

• Rohs: yes
• Product: Application Boards
• Tool Is For Evaluation Of: UC530
• Frequency: 1.575 GHz
• Operating Supply Voltage: 3.3 V
• Interface Type: UART
• Description/function: Fastrax Application Board AC530 provides the UC530 connectivity to the Fastrax Evaluation Kit or to other evaluation purposes
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Operating Supply Current: 25 mA

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Note that when using an external VDD power switch in low power modes the host needs to enable GPS operation
after initial power up by controlling GPS_ON signal (see reference circuit in chapter 7.1) to high state. The module
can control the VDD power switch autonomously via TIMER signal only after the UC530 is set to Periodic, Backup
or to AlwaysLocate™ mode by a NMEA command.
Note also that first fix position accuracy can be somewhat degraded in Power Management Modes when
compared to Full Power operation. User can improve the position accuracy by taking the 2
up.
User can exit low power Modes 3… 4 to Full Power by sending NMEA command $PMTK,225,0*2B just after the
module has woke up from previous sleep cycle.
3.4
The UC530 module self-assistance uses EASY™ (Embedded Assist System) ephemeris extension, which is
embedded in the software without any resources required from the host. The EASY™ data is stored on internal
flash memory and allows fast TTFF typ. 3 seconds over 3 days and is enabled by default.
Allow the receiver to navigate at least for 5 minutes with good GPS satellite visibility in order to collect broadcast
ephemeris and to process necessary information.
3.5
The UC530 module supports also input from server generated EPO™ file (Extended Prediction Orbit, i.e. ephemeris
extension), which can be transferred from a FTP server and allows fast TTFF typ. 10 seconds over 7/14 days.
Contact Fastrax support for details on EPO FTP server usage.
3.6
The UC530 module supports embedded logger function called LOCUS and when enabled it can log position
information to internal flash memory; default log interval is 15 seconds that provides typically > 16 h log capacity.
The LOCUS can be enabled by NMEA command $PMTK185,0*22. Contact Fastrax support for details on Locus
usage.
3.7
By default DGPS navigation mode is disabled. The host may enable DGPS/SBAS navigation mode by sending
commands ‘Enable Search of SBAS Satellites’ $PMTK313,1*2E followed by ‘Set DGPS Data Source to SBAS’
$PMTK301,2*2E. The search for suitable SBAS satellite signal is automatic.
The host may either enable DGPS/RTCM navigation mode by sending command ‘Set DGPS Data Source to RTCM’
$PMTK301,1*2D. The UART Port1 is used for RTCM message input at 9600 baud.
Note that DGPS usage is only supported at 1Hz navigation rate in Full Power mode. Note also that acquiring
necessary DGPS correction parameters may take up to 1 minute prior DGPS fix status is achieved, which is
indicated in the $GPGGA message, Fix Valid Indicator. Note also that DGPS corrections do not provide corrections
against multipath errors that are local; thus accuracy is not necessary improved in urban environments.
3.8
Standby Mode means a low quiescent (200 µA typ. at VDD) power state where receiver operation is stopped; both
the main supply VDD and the backup supply VDD_B are powered on.
The Standby Mode is entered by NMEA command $PMTK161, see chapter 3.3. Waking up from Standby state to
Full Power is controlled by host by sending any byte via host communication port.
2012-05-03
UC530_Datasheet
Self-Assistance EASY™ usage
Server Assistance EPO™ usage
Logger LOCUS usage
DGPS usage
Standby Mode
nd
or 3
rd
fix after waking