Global Sat ET-316A User manual

ET-316A
Page1of17
Version 1.2
GPS Engine Board ET-316A
Version 1.2
06/22/2007
Globalsat Technology Corporation Headquarters (Far East Century Park)
16F., No. 186, Jian-Yi Road, Chung-Ho City, Taipei Hsien 235, Taiwan
Tel: [phone]/ Fax: [phone]
E-mail : [e-mail]
Website: www.globalsat.com.tw

ET-316A
The Specifications are subject to be changed without notice. Copyright ©2007, GlobalSat Technology.
Page 2 of 17
Version 1.2
1. Product Information
Product Name: ET-316A
Product Description:
ET-316A is a compact, high performance, and low power consumption GPS engine board. It uses SiRF
Star III chipset which can track up to 20 satellites at a time and perform fast TTFF in weak signal
environments. ET-316A is suitable for the following applications:
‧ Automotive navigation
‧ Personal positioning
‧ Fleet management
‧ Mobile phone navigation
‧ Marine navigation
Product Features:
SiRF star III high performance GPS Chipset
Very high sensitivity (Tracking Sensitivity: -159 dBm)
Extremely fast TTFF (Time To First Fix) at low signal level
Two serial ports
4Mb flash
Built-in LAN
Compact size (28mm * 20 mm * 2.9mm) suitable for space-sensitive application
One size component, easy to mount on another PCB board
Support NMEA 0183 and SiRF binary protocol
Product Specifications
GPS Receiver
Chipset SiRF StarⅢ
Frequency L1, 1575.42 MHz
Code C/A Code
Protocol NMEA 0183 v2.2
Default:GGA,GSA,GSV,RMC
Support:VTG,GLL,ZDA)
SiRF binary and NMEA Command
Available Baud Rate 4,800 to 57,600 bps adjustable

ET-316A
The Specifications are subject to be changed without notice. Copyright ©2007, GlobalSat Technology.
Page 3 of 17
Version 1.2
Channels 20
Flash 4Mbit
Sensitivity Tracking:-159dBm
Cold Start 42 seconds, average
Warm Start 38 seconds, average
Hot Start 1 second, average
Reacquisition 0.1 second, average
Accuracy Position: 10 meters, 2D RMS
5 meters, 2D RMS, WAAS enabled
Velocity: 0.1 m/s
Time: 1us synchronized to GPS time
Maximum Altitude ＜18,000 meter
Maximum Velocity ＜515 meter/second
Maximum Acceleration ＜4G
Update Rate 1 Hz
DGPS WAAS, EGNOS, MSAS
Datum WGS-84
Interface
I/O Pins 2 serial ports
Physical Characteristic
Type 15-pin stamp holes
Dimensions 28.1 mm * 20 mm * 2.9 mm
DC Characteristics
Power Supply 3.3Vdc ± 5%
Backup Voltage 2.0 ~ 3.6Vdc ± 10%
Power Consumption Acquisition: 42mA
Tracking: 25mA
Environmental Range
Humidity Range 5% to 95% non-condensing
Operation Temperature -40℃ to 85℃
Storage Temperature -40℃ to 125℃

ET-316A
The Specifications are subject to be changed without notice. Copyright ©2007, GlobalSat Technology.
Page 4 of 17
Version 1.2
2. Technical Information
Block Diagram
Module Pin Assignment:
Pin NO. Pin Name Remark
1. GND Ground.
2. RF Connect to External Active Antenna. While external antenna is used, the
optional power is needed.
3. GND Ground.
4. GND Ground.
5. GND Ground.

ET-316A
The Specifications are subject to be changed without notice. Copyright ©2007, GlobalSat Technology.
Page 5 of 17
Version 1.2
6. GND Ground.
7. VIN This is the main DC supply for a 3.3V +- 5% DC input power module board.
8. BATTERY 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. The battery voltage should be between 2.0v and
5.0v.
9. GPIO1 User can use this I/O pin for special function.For example, on/off LED
10. TX This is the main transmits channel for outputting navigation and
measurement data to user’s navigation software or user written
software.Output TTL level, 0V ~ 2.85V
11. RX This is the main receive channel for receiving software commands to the
engine board from SiRFdemo software or from user written software.
12. GND Ground.
13. GND Ground.
14. TXB NC
15. RXB NC

ET-316A
The Specifications are subject to be changed without notice. Copyright ©2007, GlobalSat Technology.
Page 6 of 17
Version 1.2
Application Circuit
GPS Active Antenna Specification(Recommendation)
Frequency: 1575.42+2 MHz
Axial Ratio: 3 dB Typical
output Impedance: 50Ω
Polarization: RHCP
Amplifier Gain :18~22dB Typical
Output VSWR: 2.0 Max.
Noise Figure: 2.0 dB Max

ET-316A
The Specifications are subject to be changed without notice. Copyright ©2007, GlobalSat Technology.
Page 7 of 17
Version 1.2
Dimensions

ET-316A
The Specifications are subject to be changed without notice. Copyright ©2007, GlobalSat Technology.
Page 8 of 17
Version 1.2
Recommend Layout PAD

ET-316A
The Specifications are subject to be changed without notice. Copyright ©2007, GlobalSat Technology.
Page 9 of 17
Version 1.2
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,12158.3416,W,1,07,1.0,9.0,M,,,,0000*18
Table B-2 GGA Data Format
Name Exam
p
le Units Descri
p
tio
n
Messa
g
e ID $GPGGA GGA
p
rotocol heade
r
UTC Time 161229.487 hhmmss.sss
Latitude 3723.2475 ddmm.mmmm
N
/S Indicato
r
N
N
=north or S=south
Lon
g
itude 12158.3416 dddm
m
.mmm
m
E/W Indicato
r
W E=east or W=wes
t
Position Fix Indicato
r
1 See Table B-3
Satellites Use
d
07 Ran
g
e 0 to 12
HDOP 1.0 Horizontal Dilution of Precision
MSL Altitude19.0 meters
Units M meters
Geoid Se
p
aration1meters
Units M meters
A
g
e of Diff. Corr. second
N
ull fields when DGPS is not used
Diff. Ref. Station ID 0000
Checksu
m
*18
<CR><LF> End of messa
g
e termination
SiRF Technology Inc. does not support geoid corrections. Values are WGS84 ellipsoid heights.
Table B-3 Position Fix Indicator
Va l u e D e s c r i
p
tion
0 Fix not available or invali
d
1 GPS SPS Mode, fix vali
d
2 Differential GPS, SPS Mode , fix vali
d
3 GPS PPS Mode, fix vali
d
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

ET-316A
The Specifications are subject to be changed without notice. Copyright ©2007, GlobalSat Technology.
Page 10 of 17
Version 1.2
TableB-4GLLDataFormat
Name Exam
p
le Units Descri
p
tion
Messa
g
e ID $GPGLL GLL
p
rotocol heade
r
Latitude 3723.2475 ddmm.mmmm
N
/S Indicato
r
n
N
=north or S=south
Lon
g
itude 12158.3416 dddmm.mmm
m
E/W Indicato
r
W E=east or W=wes
t
UTC Position 161229.487 hhmmss.sss
Status A A=data valid or V=data not valid
Checksu
m
*2C
<CR><LF> End of messa
g
e 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
TableB-5GSADataFormat
Name Example Units Description
Message ID $GPGSA GSA protocol header
Mode1 A See Table B-6
Mode2 3 See Table B-7
Satellite Used107 Sv on Channel 1
Satellite Used102 Sv on Channel 2
…..
Satellite Used1Sv 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
<CR><LF> End of message termination
1. Satellite used in solution.
TableB-6Mode1
Value Description
M Manual-forced to operate in 2D or 3D mode
A 2Dautomatic-allowed to automatically switch 2D/3D
TableB-7Mode2
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: