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Related Manuals for Globalsat ET-318
Summary of Contents for Globalsat ET-318
- Page 1 PRODUCT USER MANUAL GPS ENGINE BOARD ET-318 Version 1.0 GlobalSat Technology Corporation 北 路 186 16 樓( 16, No.186,Chien 1 Road, 235Chung Ho City,Taipei Hsien, Taiwan ,R.O.C. Tel: 886-2-8226-3799(Rep.) Fax: 886-2-8226-3899 Web: www.globalsat.com.tw E-mail: service@globalsat.com.tw...
- Page 2 Features: SiRF star high performance GPS Chip Set Very high sensitivity (Tracking Sensitivity: -159 dBm) Extremely fast TTFF (Time To First Fix) at low signal level Compact size (15.2mm * 14 mm * 2.8mm) suitable for space-sensitive application One size component, easy to mount on another PCB board Support NMEA 0183 and SiRF binary protocol Specification: General...
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Page 3: Power Consumption
Power Main power input 3.3V +- 5% DC input Power consumption 42mA (Continuous mode) 36mA (Trickle power mode Interface Dimension 15.2mm * 14 mm * 2.8mm Baud rate 4,800 to 57,600 bps adjustable Output message SiRF binary or NMEA 0183 GGA, GSA, GSV, RMC, VTG, GLL GPS Passive (or Active )Antenna Specification(Recommendation) Frequency: 1575.42+2 MHz Axial Ratio: 3 dB Typical... -
Page 4: Pin Assignment
Pin Assignment Signal Name Description Analog Ground RF_IN GPS Signal input Analog Ground NRESET Reset (Active low) VCC_IN DC Supply Voltage input VBAT Backup voltage supply Serial port B Serial port B Analog Ground BOOTSEL Boot mode Serial port A Serial port A GPIO1 General –purpose I/O... - Page 5 Definition of Pin assignment VCC_IN This is the main DC supply for a 3.3V +- 5% DC input power module board. GND provides the ground for digital part. BOOTSEL Set this pin to high for programming flash. This is the main receiver channel and is used to receive software commands to the board from SIRFdemo software or from user written software.
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Page 6: Application Circuit
Backup battery (V_BAT) This is the battery backup input that powers the SRAM and RTC when main power is removed. Typical current draw is 15uA. Without an external backup battery, the module/engine board will execute a cold star after every turn on. To achieve the faster start-up offered by a hot or warm start, a battery backup must be connected. - Page 7 Recommend Layout PAD Mechanical Layout...
- Page 8 SOFTWARE COMMAND NMEA Output Command GGA-Global Positioning System Fixed Data Table B-2 contains the values for the following example: $GPGGA,161229.487,3723.2475,N,12158.3416,W,1,07,1.0,9.0,M,,,,0000*18 Table B-2 GGA Data Format Name Example Units Description Message ID $GPGGA GGA protocol header UTC Time 161229.487 hhmmss.sss Latitude 3723.2475 ddmm.mmmm N/S Indicator...
- Page 9 GLL-Geographic Position-Latitude/Longitude Table B-4 contains the values for the following example: $GPGLL,3723.2475,N,12158.3416,W,161229.487,A*2C Table B-4 GLL Data Format Name Example Units Description Message ID $GPGLL GLL protocol header Latitude 3723.2475 ddmm.mmmm N/S Indicator N=north or S=south Longitude 12158.3416 dddmm.mmmm E/W Indicator E=east or W=west UTC Position 161229.487...
- Page 10 GSV-GNSS Satellites in View Table B-8 contains the values for the following example: $GPGSV,2,1,07,07,79,048,42,02,51,062,43,26,36,256,42,27,27,138,42*71 $GPGSV,2,2,07,09,23,313,42,04,19,159,41,15,12,041,42*41 Table B-8 GSV Data Format Name Example Description Message ID $GPGSV GSV protocol header Number of Messages Range 1 to 3 Message Number Range 1 to 3 Satellites in View Satellite ID Channel 1(Range 1 to 32)
- Page 11 VTG-Course Over Ground and Ground Speed $GPVTG,309.62,T,,M,0.13,N,0.2,K*6E Name Example Units Description Message ID $GPVTG VTG protocol header Course 309.62 degrees Measured heading Reference True Course degrees Measured heading Reference Magnetic Speed 0.13 knots Measured horizontal speed Units Knots Speed Km/hr Measured horizontal speed Units Kilometers per hour...
- Page 12 Data bits <StopBits> <Parity> 0=None, 1=Odd, 2=Even Example 1: Switch to SiRF Binary protocol at 9600,8,N,1 $PSRF100,0,9600,8,1,0*0C<CR><LF> Example 2: Switch to User1 protocol at 38400,8,N,1 $PSRF100,4,38400,8,1,0*38<CR><LF> **Checksum Field: The absolute value calculated by exclusive-OR the 8 data bits of each character in the Sentence,between, but excluding “$”...
- Page 13 <Y> Y coordinate position INT32 <Z> Z coordinate position INT32 <ClkOffset> Clock offset of the receiver in Hz, Use 0 for last saved value if available. If this is unavailable, a default value of 75000 for GSP1, 95000 for GSP 1/LX will be used. INT32 <TimeOf Week>...
- Page 14 The default communication parameters for PORT B are 9600 Baud, 8data bits, 0 stop bits, and no parity. If a DGPS receiver is used which has different communication parameters, use this command to allow the receiver to correctly decode the data. When a valid message is received, the parameters will be stored in battery backed SRAM and then the receiver will restart using the saved parameters.
- Page 15 Example 1: Query the GGA message with checksum enabled PSRF103,00,01,00,01*25 Example 2: Enable VTG message for a 1Hz constant output with checksum enabled PSRF103,05,00,01,01*20 Example 3: Disable VTG message PSRF103,05,00,00,01*21 E). LLA Navigation lnitialization ID:104 Parameters required to start using Lat/Lon/Alt This command is used to initialize the module for a warm start, by providing current position (in Latitude, Longitude, Altitude coordinates), clock offset, and time.
- Page 16 and negative west of Greenwich Float, possibly signed <Alt> Altitude position float, possibly signed <ClkOffset> Clock Offset of the receiver in Hz, use 0 for last saved value if available. If this is unavailable, a default value of 75000 for GSP1, 95000 for GSP1/LX will be used.
- Page 17 Example: Debug On PSRF105,1*3E Example: Debug Off PSRF105,0*3F G). Select Datum ID:106 Selection of datum to be used for coordinate Transformations GPS receivers perform initial position and velocity calculations using an earth-centered earth-fixed (ECEF) coordinate system. Results may be converted to an earth model (geoid) defined by the selected datum.