PRODUCT USER MANUAL GPS ENGINE BOARD ET-314
Contents
1. from SIRFdemo software or from user written software PS Pull up if not used RXB This is the auxiliary receiving channel and is used to input differential corrections to the board to enable DGPS navigation PS Pull up if not used TXA This is the main transmitting channel and is used to output navigation and measurement data to SiRFdemo or user written software TXB For user s application not currently used RF_ON This pin indicates state of RF voltage RF_IN This pin receiver signal of GPS analog due to the RF characteristics of the signal the design has to certain criteria The line on the PCB from the antenna or antenna connector has to be a controlled microstrip line at 500 V_ANT_IN This pin is reserved an external DC power supply for active antenna If using 3 0V active antenna pin 19 has to be connected to pin 20 If using 3 3V or 12V active antenna this pin has to be connected to 3 3V or 5V power supply VCC_RF This pin provides DC voltage 3 0 for active antenna Reset This pin provides an active low reset input to the board It causes the board to reset and start searching for satellites If not utilized it may be left open PPS This pin provides one pulse per second output from the board which is synchronized to GPS time This is not available in Trickle Power mode Backup battery V BAT This is the battery backup input that powers the SRAM and RTC when main power is removed Typical curre2. 0 0C lt CR gt lt LF gt Example 2 Switch to Userl protocol at 38400 8 N 1 PSRF100 4 38400 8 1 0 38 lt CR gt lt LF gt Checksum Field The absolute value calculated by exclusive OR the 8 data bits of eachcharacter in the Sentence between but excluding and The hexadecimal value of the most significant and least significant 4 bits of the result are convertted to two ASCII characters 0 9 A F for transmission The most significant character is transmitted first lt CR gt lt LF gt Hex OD OA B Navigation Initialization ID 101 Parameters required for start This command is used to initialize the module for a warm start by providing current position in X Y Z coordinates clock offset and time This enables the receiver to search for the correct satellite signals at the correct signal parameters Correct initialization parameters will enable the receiver to acquire signals more quickly and thus produce a faster navigational solution When a valid Navigation Initialization command is received the receiver will restart using the input parameters as a basis for satellite selection and acquisition Format SPSRF101 lt X gt lt Y gt lt Z gt lt ClkOffset gt lt TimeOf Week gt lt WeekNo gt lt chnlCount gt lt R esetCfg gt CKSUM lt CR gt lt LF gt lt X gt X coordinate position INT32 lt Y gt Y coordinate position INT32 lt Z gt Z coordinate position INT32 lt ClkOffset gt Cl
3. 09 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 T True Course degrees Measured heading Reference M Magnetic Speed 0 13 knots Measured horizontal speed Units N Knots Speed 0 2 Km hr Measured horizontal speed Units K Kilometers per hour Checksum 6E lt CR gt lt LF gt End of message termination 2 2 NMEA Input Command A Set Serial Port ID 100 Set PORTA parameters and protocol This command message is used to set the protocol SiRF Binary NMEA or USERI and or the communication parameters baud data bits stop bits parity Generally this command would be used to switch the module back to SiRF Binary protocol mode where a more extensive command message set is available For example to change navigation parameters 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 Format PSRF100 lt protocol gt lt baud gt lt DataBits gt lt StopBits gt lt Parity gt CKSUM lt CR gt lt LF gt lt protocol gt 0 SiRF Binary 1 NMEA 4 USERI lt baud gt 1200 2400 4800 9600 19200 38400 lt DataBits gt 8 7 Note that SiRF protocol is only valid f8 Data bits lt StopBits gt 0 1 lt Parity gt 0 None 1 Odd 2 Even Example 1 Switch to SiRF Binary protocol at 9600 8 N 1 PSRF100 0 9600 8 1
4. 416 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 N Nznorth or S south Longitude 12158 3416 dddmm mmmm E W Indicator W E east or W west Position Fix Indicator 1 See Table B 3 Satellites Used 07 Range 0 to 12 HDOP 1 0 Horizontal Dilution of Precision MSL Altitude 9 0 meters Units M meters Geoid Separation meters Units M meters Age of Diff Corr second Null fields when DGPS is not used Diff Ref Station ID 0000 Checksum 18 lt CR gt lt LF gt End of message termination SiRF Technology Inc does not support geoid corrections Values are WGS84 ellipsoid heights Table B 3 Position Fix Indicator Description Fix not available or invalid GPS SPS Mode fix valid Differential GPS SPS Mode fix valid GPS PPS Mode fix valid 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 N north or S south Longitude 12158 3416 dddmm mmmm E W Indicator W E east or W west UTC Position 161229 487 hhmmss sss Status A A d
5. A Zh E M Globaloat sex dr RAED RAT PRODUCT USER MANUAL GPS ENGINE BOARD ET 314 Features SiRF starlll 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 25 4mm 25 4 mm 3 3mm suitable for space sensitive application One size component easy to mount on another PCB board Support NMEA 0183 and SiRF binary protocol Specification General Chipset Frequency C A code Channels Sensitivity Accuracy Position Velocity Time Datum Default Acquisition Time Reacquisition Hot start Warm start Cold start Dynamic Conditions Altitude Velocity Acceleration Jerk SiRF Starlll L1 1575 42 MHz 1 023 MHz chip rate 20 channel all in view tracking 159 dBm 10 meters 2D RMS 5 meters 2D RMS WAAS enabled 0 1 m s us synchronized to GPS time WGS 84 0 1 sec average sec average 38 sec average 42 sec average 18 000 meters 60 000 feet max 515 meters second 1000 knots max Less than 4g 20m sec 3 Power Main power input 3 3V 5 DC input Power consumption 68mA Continuous mode Interface Dimension 25 4mm 25 4 mm 3 3mm Baud rate 4 800 to 57 600 bps adjustable Output message SiRF binary or NMEA 0183 GGA GSA GSV RMC VTG GLL GPS Antenna Specification Recommendation Frequency 1575 42 2 MHz Axial Ratio 3 dB Typical output Impeda
6. TOKYO OKINAWA EE a IE End of message termination
7. ata valid or V data not valid Checksum 2C lt CR gt lt LF gt End of message termination GSA GNSS DOP and Active Satellites Table B 5 contains the values for the following example GPGSA A 3 07 02 26 27 09 04 15 1 8 1 0 1 5 33 Table B 5 GSA Data Format Name Example Units Description Message ID GPGSA GSA protocol header Model A See Table B 6 Mode2 3 See Table B 7 Satellite Used 07 Sv on Channel 1 Satellite Used 02 Sv on Channel 2 Satellite Used Sv on Channel 12 PDOP 1 8 Position dilution of Precision HDOP 1 0 Horizontal dilution of Precision VDOP 1 5 Vertical dilution of Precision Checksum 33 lt CR gt lt LF gt End of message termination 1 Satellite used in solution Table B 6 Model Value Description M Manual forced to operate in 2D or 3D mode A 2Dautomatic allowed to automatically switch 2D 3D Table B 7 Mode 2 Value Description 1 Fix Not Available 2 2D 3 3D GSV GNSS Satellites in View Table B 8 contains the values for the following example GPGSV2 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 2 Range 1 to 3 Message Number 1 Range 1 to 3 Satellites in View 07 Satel
8. lite ID 07 Channel 1 Range 1 to 32 Elevation 79 degrees Channel 1 Maximum90 Azimuth 048 degrees Channel 1 True Range 0 to 359 SNR C No 42 dBHz Range 0 to 99 null when not tracking Satellite ID 27 Channel 4 Range 1 to 32 Elevation 27 Degrees Channel 4 Maximum90 Azimuth 138 Degrees Channel 4 True Range 0 to 359 SNR C No 42 dBHz Range 0 to 99 null when not tracking Checksum 71 lt CR gt lt LF gt End of message termination Depending on the number of satellites tracked multiple messages of GSV data may be required RMC Recommended Minimum Specific GNSS Data Table B 10 contains the values for the following example GPRMC 161229 487 A 3723 2475 N 12158 3416 W 0 13 309 62 120598 10 Table B 10 RMC Data Format Name Example Units Description Message ID GPRMC RMC protocol header UTC Time 161229 487 hhmmss sss Status A A data valid or V data not valid Latitude 3723 2475 ddmm mmmm N S Indicator N N north or S south Longitude 12158 3416 dddmm mmmm E W Indicator W E east or Wzwest Speed Over Ground 0 13 knots Course Over Ground 309 62 degrees True Date 120598 ddmmyy Magnetic Variation degrees E east or W west Checksum 10 lt CR gt lt LF gt End of message termination SiRF Technology Inc does not support magnetic declination All course over ground data are geodetic WGS48 directions VTG Course Over Ground and Ground Speed GPV TG 3
9. nce 500 Polarization RHCP Amplifier Gain 20 26dB Typical Output VSWR 2 0 Max Noise Figure 2 0 dB Max Environmental Operating Temp 40 C to 85 C Pin Assignment 15 4 13 12 n 109878524321 16 17 18 19 20 2122232412526 27 28 29 30 Pin Signal Name I O Description 1 VCC DC Supply Voltage input 2 GND G Ground 3 Boot select Boot mode 4 RXA Serial port A 5 TXA O Serial port A 6 TXB O Serial port B 7 RXB Serial port B 8 GPIO14 I O General purpose I O 9 RF ON 10 GND G Digital Ground E GND A G Analog Ground 17 RF IN GPS Signal input 18 GND A G Analog Ground 19 V_ANT_IN Active Antenna Bias voltage 20 VCC_RF O Supply Antenna Bias voltage 21 V_BAT Backup voltage supply 22 Reset Reset Active low 23 GPIO10 y o General purpose I O 24 GPIO1 y o General purpose I O 25 GPIO5 y o General purpose I O 26 GPON us support Eben Rules Ht only 27 GPIO13 y o General purpose I O 28 GPIO15 y o General purpose I O 29 PPS O One pulse per second 30 GND G Digital Ground Definition of Pin assignment VCC This is the main DC supply for a 3 3V 5 DC input power module board GND GND provides the ground for digital part Boot select Set this pin to high for programming flash RXA This is the main receiver channel and is used to receive software commands to the board
10. nt 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 The battery voltage should be between 2 0v and 5 0v Without an external backup battery or super cap the TMP will execute a cold start after every power on To achieve the faster start up offered by a hot or warm start either a battery backup must be connected or a super cap installed To maximize battery lifetime the battery voltage should not exceed the supply voltage and should be between 2 5V and 3 6V With the super cap B1 installed and after at least ten minutes of continuous operation the data retention is about seven hours Note that even though all other components are rated at 30 to 85 deg C a typical super cap is specified over a temperature range of 25 to 70 deg C and a typical rechargeable Lithium battery is over 20 to 70 deg C GPIO Functions Several I Os are connected to the digital interface connector for custom applications Application Circuit VCC 9 1PPS GPIO_15 Bootselect GPIO_15 GPIO_13 GPIO 13 GPIO 0 GPIO 5 GPIO 1 GPIO 10 GPIO 14 GPIO 14 GPIO 10 RF ON NRESET GND V BAT VCC_RF V_ANT A_GND RF_IN A_GND 1 Ground Planes ET 314 GPS receiver needs two differen
11. ock offset of the receiver in Hz Use O 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 GPS Time Of Week UINT32 WeekNo GPS Week Number UINT16 Week No and Time Of Week calculation from UTC time chnlCount Number of channels to use 1 12 If your CPU throughput is not high enough you could decrease needed throughput by reducing the number of active channels UBYTE lt ResetCfg gt bit mask 0x01 Data Valid warm hotstarts 1 0x02 clear ephemeris warm start 1 0x04 clear memory Cold start 1 UBYTE Example Start using known position and time O PSRF101 2686700 4304200 385 1624 96000 497260 921 12 3 7F C Set DGPS Port ID 102 Set PORT B parameters for DGPS input This command is used to control Serial Port B that is an input only serial port used to receive RTCM differential corrections Differential receivers may output corrections using different communication parameters 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 Format PSRF102 lt Baud gt lt DataBits gt lt S
12. rt by providing current position in Latitude Longitude Altitude coordinates clock offset and time This enables the receiver to search for the correct satellite signals at the correct signal parameters Correct initialization parameters will enable the receiver to acquire signals more quickly and thus will produce a faster navigational soution When a valid LLANavigationInitialization command is received the receiver will restart using the input parameters as a basis for satellite selection and acquisition Format PSRF104 lt Lat gt lt Lon gt lt Alt gt lt ClkOffset gt lt TimeOfWeek gt lt WeekNo gt lt ChannelCount gt lt ResetCfg gt CKSUM lt CR gt lt LF gt lt Lat gt Latitude position assumed positive north of equator and negative south of equator float possibly signed lt Lon gt Longitude position it is assumed positive east of Greenwich and negative west of Greenwich Float possibly signed lt Alt gt Altitude position float possibly signed lt ClkOffset gt Clock Offset of the receiver in Hz use O for last saved value if available If this is unavailable a default value of 75000 for GSP1 95000 for GSP1 LX will be used INT32 lt TimeOfWeek gt GPS Time Of Week UINT32 lt WeekNo gt GPS Week Number UINT16 lt ChannelCount gt Number of channels to use 1 12 UBYTE lt ResetCfg gt bit mask 0x01 Data Valid warm hot starts 1 0x02 clear ephemeris warm start 1 0x04 clear memory Cold star
13. t 1 UBYTE Example Start using known position and time O PSRF104 37 3875111 121 97232 0 96000 237759 922 12 3 37 F Development Data On Off ID 105 Switch Development Data Messages On Off Use this command to enable development debug information if you are having trouble getting commands accepted Invalid commands will generate debug information that should enable the user to determine the source of the command rejection Common reasons for input command rejection are invalid checksum or parameter out of specified range This setting is not preserved across a module reset Format PSRF105 lt debug gt CKSUM lt CR gt lt LF gt lt debug gt 0 Off 1 On 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 The default datum is WGS 84 World Geodetic System 1984 which provides a worldwide common grid system that may be translated into local coordinate systems or map datums Local map datums are a best fit to the local shape of the earth and not valid worldwide Examples Datum select TOKYO MEAN PSRF106 178 32 Message ID SPSRF106 Do PSRF106 protocol header 21 WGS84 178 TOKYO MEAN 179 TOKYO JAPAN 180 TOKYO KOREA 181
14. t ground planes The GND_A pin 11 12 13 149 19 18 18 shall be connect to analog ground The GND pin 2 10 2 Serial Interface 30 connect to digital ground The Serial interface pin RXA TX1 TXB RXB is recommended to pull up 10KQ It can increase the stability of serial data 3 Backup Battery It s recommended to connect a backup battery to V BAT In order to enable the warm and hot start features of the GPS receiver If you don t intend to use a backup battery connect this pin to GND or open If you use backup battery shall need to add a bypassing capacitor 10uF at V bat trace It can reduce noise and increase the stability Antenna s Connecting to the antenna has to be routed on the PCB The transmission line must to controlled impedance to connect RF IN to the antenna or antenna connector of your choice 5 Active antenna bias voltage The Vcc RF pin pin 20 is providing voltage 3 3V If you use active antenna you can connect this pin to V ANT IN pin pin 19 to provide bias voltage of active Recommend Layout PAD J hl i 1 j n F Eu E be Mechanical Layout 25 4 0 2 24 4 0 49 25 4t0 2 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 3
15. topBits gt lt Parity gt CKSUM lt CR gt lt LF gt lt baud gt 1200 2400 4800 9600 19200 38400 lt DataBits gt 8 lt StopBits gt 0 1 lt Parity gt 0 None Odd 1 Even 2 Example Set DGPS Port to be 9600 8 N 1 O PSRF102 9600 8 1 0 12 D Query Rate Control ID 103 Query standard NMEA message and or set output rate This command is used to control the output of standard NMEA message GGA GLL GSA GSV RMC VTG Using this command message standard NMEA message may be polled once or setup for periodic output Checksums may also be enabled or disabled depending on the needs of the receiving program NMEA message settings are saved in battery backed memory for each entry when the message is accepted Format PSRF103 lt msg gt lt mode gt lt rate gt lt cksumEnable gt CKSUM lt CR gt lt LF gt lt msg gt 0 GGA 1 GLL 2 GSA 3 GSV 4 RMC 5 VTG lt mode gt 0 SetRate 1 Query lt rate gt Output every lt rate gt seconds off 0 max 255 lt cksumEnable gt 0 disable Checksum 1 Enable checksum for specified message 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 L PSRF103 05 00 01 01 20 Example 3 Disable VTG message PSRF103 05 00 00 01 21 E LLA Navigation Initialization ID 104 Parameters required to start using Lat Lon Alt This command is used to initialize the module for a warm sta
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