Download

LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
1
Product name
Description
Version
MC-1722
Datasheet of MC-1722 GPS module
1.0
Introduction
LOCOSYS GPS MC-1722 module features high sensitivity and low power consumption. This GPS
module is powered by MediaTek, it can provide you with superior sensitivity and performance even in urban
canyon and dense foliage environment.
This module supports hybrid ephemeris prediction to achieve faster cold start. One is self-generated
ephemeris prediction that is no need of both network assistance and host CPU’s intervention. This is valid for
up to 3 days and updates automatically from time to time when GPS module is powered on and satellites are
available. The other is server-generated ephemeris prediction that gets from an internet server. This is valid
for up to 14 days. Both ephemeris predictions are stored in the on-board flash memory and perform a cold
start time less than 15 seconds.
2
Features
3
MediaTek high sensitivity solution
Support 66-channel GPS
Low power consumption
Fast TTFF at low signal level
Built-in 12 multi-tone active interference canceller
Free hybrid ephemeris prediction to achieve faster cold start
Built-in data logger
Up to 10 Hz update rate
±11ns high accuracy time pulse (1PPS)
Capable of SBAS (WAAS, EGNOS, MSAS, GAGAN)
Support Japan QZSS
Indoor and outdoor multi-path detection and compensation
Small form factor 22.4 x 17 x 2.2 mm
SMD type with stamp holes; RoHS compliant
ISO/TS 16949 quality control
Application
Personal positioning and navigation
Automotive navigation
Marine navigation
Page 1/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
Fig 3-1 System block diagram.
Fig 3-2 Typical application circuit that uses passive antenna.
Page 2/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
GPS active
antenna
LNA
15
GND
16
RF_IN
17
GND
18
VCC_RF
19
V_ANT
20
NC
14
GND
13
GND
12
NC
11
V_BCKP
10
/RESET
9
NC
2~4.3V
Battery
keep alive to get
hot start and AGPS start
MC-1722
21
NC
22
NC
23
NC
24
NC
25
NC
26
NC
27
NC
28
TIMEPULSE
8
7
6
5
4
3
TX
2
NC
1
NC
NC
GND
VCC
NC
RX
output
3.3V
LDO
TX
RX
3.3V
VCC
GND
Micro
processor
Fig 3-3 Typical application circuit that uses active antenna.
Page 3/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
Fig 3-4 Typical application circuit that has supervisor of the external active antenna.
Page 4/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
4
GPS receiver and antenna
4.1 GPS receiver
Chip
MediaTek MT3339
Frequency
L1 1575.42MHz, C/A code
Channels
Support 66 channels (22 Tracking, 66 Acquisition)
Update rate
1Hz default, up to 10Hz
Sensitivity
Acquisition Time
Tracking
-162dBm, up to -165dBm (with external LNA)
Cold start
-143dBm, up to -148dBm (with external LNA)
Hot start (Open Sky)
< 1s (typical)
Hot start (Indoor)
< 30s
32s (typical) without AGPS
Cold Start (Open Sky)
< 15s (typical) with AGPS (hybrid ephemeris prediction)
Position Accuracy
Autonomous
3m (2D RMS).
SBAS
2.5m (depends on accuracy of correction data).
Max. Altitude
< 50,000 m
Max. Velocity
< 515 m/s
Protocol Support
NMEA 0183 ver 3.01
9600 bps(2), 8 data bits, no parity, 1 stop bits (default)
1Hz: GGA, GLL, GSA, GSV, RMC, VTG
Note 1: Both baud rate and output message rate are configurable.
5
Software interface
5.1 NMEA output message
Table 5.1-1 NMEA output message
NMEA record
Description
GGA
Global positioning system fixed data
GLL
Geographic position - latitude/longitude
GSA
GNSS DOP and active satellites
GSV
GNSS satellites in view
RMC
Recommended minimum specific GNSS data
VTG
Course over ground and ground speed
GGA--- Global Positioning System Fixed Data
Table 5.1-2 contains the values for the following example:
$GPGGA,053740.000,2503.6319,N,12136.0099,E,1,08,1.1,63.8,M,15.2,M,,0000*64
Table5.1- 2 GGA Data Format
Name
Example
Message ID
$GPGGA
Units
Description
GGA protocol header
Page 5/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
UTC Time
053740.000
hhmmss.sss
Latitude
2503.6319
ddmm.mmmm
N/S indicator
N
N=north or S=south
Longitude
12136.0099
dddmm.mmmm
E/W Indicator
E
E=east or W=west
Position Fix Indicator
1
See Table 5.1-3
Satellites Used
08
Range 0 to 12
HDOP
1.1
Horizontal Dilution of Precision
MSL Altitude
63.8
mters
Units
M
mters
Geoid Separation
15.2
mters
Units
M
mters
Age of Diff. Corr.
second
Diff. Ref. Station ID
0000
Checksum
*64
<CR> <LF>
Null fields when DGPS is not used
End of message termination
Table 5.1-3 Position Fix Indicators
Value
Description
0
Fix not available or invalid
1
GPS SPS Mode, fix valid
2
Differential GPS, SPS Mode, fix valid
3-5
Not supported
6
Dead Reckoning Mode, fix valid
GLL--- Geographic Position – Latitude/Longitude
Table 5.1-4 contains the values for the following example:
$GPGLL,2503.6319,N,12136.0099,E,053740.000,A,A*52
Table 5.1-4 GLL Data Format
Name
Example
Units
Description
Message ID
$GPGLL
GLL protocol header
Latitude
2503.6319
ddmm.mmmm
N/S indicator
N
N=north or S=south
Longitude
12136.0099
dddmm.mmmm
E/W indicator
E
E=east or W=west
UTC Time
053740.000
hhmmss.sss
Status
A
A=data valid or V=data not valid
Page 6/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
Mode
A
Checksum
*52
A=autonomous, D=DGPS, E=DR
<CR> <LF>
End of message termination
GSA---GNSS DOP and Active Satellites
Table 5.1-5 contains the values for the following example:
$GPGSA,A,3,24,07,17,11,28,08,20,04,,,,,2.0,1.1,1.7*35
Table 5.1-5 GSA Data Format
Name
Example
Units
Description
Message ID
$GPGSA
GSA protocol header
Mode 1
A
See Table 5.1-6
Mode 2
3
See Table 5.1-7
ID of satellite used
24
Sv on Channel 1
ID of satellite used
07
Sv on Channel 2
….
….
ID of satellite used
Sv on Channel 12
PDOP
2.0
Position Dilution of Precision
HDOP
1.1
Horizontal Dilution of Precision
VDOP
1.7
Vertical Dilution of Precision
Checksum
*35
<CR> <LF>
End of message termination
Table 5.1-6 Mode 1
Value
Description
M
Manual- forced to operate in 2D or 3D mode
A
Automatic-allowed to automatically switch 2D/3D
Table 5.1-7 Mode 2
Value
Description
1
Fix not available
2
2D
3
3D
GSV---GNSS Satellites in View
Table 5.1-8 contains the values for the following example:
$GPGSV,3,1,12,28,81,285,42,24,67,302,46,31,54,354,,20,51,077,46*73
$GPGSV,3,2,12,17,41,328,45,07,32,315,45,04,31,250,40,11,25,046,41*75
$GPGSV,3,3,12,08,22,214,38,27,08,190,16,19,05,092,33,23,04,127,*7B
Table 5.1-8 GSV Data Format
Page 7/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
Name
Example
Message ID
Units
Description
$GPGSV
GSV protocol header
Total number of messages
3
Range 1 to 3
Message number1
1
Range 1 to 3
Satellites in view
12
Satellite ID
28
Elevation
81
degrees
Channel 1 (Range 00 to 90)
Azimuth
285
degrees
Channel 1 (Range 000 to 359)
SNR (C/No)
42
dB-Hz
Channel 1 (Range 00 to 99, null when not tracking)
Satellite ID
20
Elevation
51
degrees
Channel 4 (Range 00 to 90)
Azimuth
077
degrees
Channel 4 (Range 000 to 359)
SNR (C/No)
46
dB-Hz
Channel 4 (Range 00 to 99, null when not tracking)
Checksum
*73
1
Channel 1 (Range 01 to 32)
Channel 4 (Range 01 to 32)
<CR> <LF>
End of message termination
1. Depending on the number of satellites tracked multiple messages of GSV data may be required.
RMC---Recommended Minimum Specific GNSS Data
Table 5.1-9 contains the values for the following example:
$GPRMC,053740.000,A,2503.6319,N,12136.0099,E,2.69,79.65,100106,,,A*53
Table 5.1-9 RMC Data Format
Name
Example
Message ID
$GPRMC
RMC protocol header
UTC Time
053740.000
hhmmss.sss
Status
A
A=data valid or V=data not valid
Latitude
2503.6319
ddmm.mmmm
N/S Indicator
N
N=north or S=south
Longitude
12136.0099
dddmm.mmmm
E/W Indicator
E
E=east or W=west
Speed over ground
2.69
knots
Course over ground
79.65
degrees
Date
100106
Description
True
ddmmyy
degrees
Magnetic variation
Variation sense
E=east or W=west (Not shown)
Mode
A
Checksum
*53
<CR> <LF>
Units
A=autonomous, D=DGPS, E=DR
End of message termination
Page 8/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
VTG---Course Over Ground and Ground Speed
Table 5.1-10 contains the values for the following example:
$GPVTG,79.65,T,,M,2.69,N,5.0,K,A*38
Table 5.1-10 VTG Data Format
Name
Example
Message ID
$GPVTG
Course over ground
79.65
Reference
T
Units
VTG protocol header
degrees
Measured heading
True
degrees
Course over ground
Description
Measured heading
Reference
M
Magnetic
Speed over ground
2.69
Units
N
Speed over ground
5.0
Units
K
Kilometer per hour
Mode
A
A=autonomous, D=DGPS, E=DR
Checksum
*38
knots
Measured speed
Knots
km/hr
<CR> <LF>
Measured speed
End of message termination
5.2 Proprietary NMEA input/output message
Please refer to MTK proprietary message.
5.3 Examples to configure the power mode of GPS module
The GPS module supports different power modes that user can configure by issuing
software commands.
5.3.1 Standby mode
User can issue software command to make GPS module go into standby mode that
consumes less than 200uA current. GPS module will be awaked when receiving any byte.
The following flow chart is an example to make GPS module go into standby mode and
then wake up.
Page 9/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
Start
GPS module is powered on
and in normal operation mode
Change GPS to
standby mode
Wake up
GPS module
unsigned char StandbyMode[] = {"$PMTK161,0*28\x0D\x0A"};
Yes
Issue any byte to
wake up GPS module
No
GPS module will return {"$PMTK010,002*2D\x0D\x0A"}
and start normal operation.
End
5.3.2 Periodic mode
When GPS module is commanded to periodic mode, it will be in operation and
standby periodically. Its status of power consumption is as below chart.
The following flow chart is an example to make GPS module go into periodic mode
Page 10/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
and then back to normal operation mode.
Start
GPS module is powered on
Change GPS to periodic mode with
3000ms on and 12000ms standby
if position fix is available, otherwise
(18000, 72000) ms will be applied.
unsigned char PeriodicMode[] =
{"$PMTK225,2,3000,12000,18000,72000*15\x0D\x0A"};
Note: minimum on time is 2000ms.
maximum standby time is 518400000ms (6 days)
GPS module will return message
"$PMTK001,225,3*35\x0D\x0A"
if command is accepted.
Set GPS to normal
operation mode?
Yes
GPS is in
standby now
Yes
Issue any byte to GPS
and wait it awake
No
No
Issue command of
normal operation mode
unsigned char NormalMode[] =
{"$PMTK225,0*2B\x0D\x0A"};
GPS module will return message
"$PMTK001,225,3*35\x0D\x0A"
if command is accepted.
End
GPS is in periodic mode
End
GPS is in normal mode
5.3.3 AlwaysLocateTM mode
AlwaysLocateTM is an intelligent controller of periodic mode. Depending on the
environment and motion conditions, GPS module can adaptively adjust working/standby
time to achieve balance of positioning accuracy and power consumption. In this mode, the
host CPU does not need to control GPS module until the host CPU needs the GPS position
data. The following flow chart is an example to make GPS module go into
AlwaysLocateTm mode and then back to normal operation mode.
Page 11/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
Note: AlwaysLocateTM is a trade mark of MTK.
Start
GPS module is powered on
Change GPS to
AlwaysLocate mode
unsigned char AlwaysLocateMode[] =
{"$PMTK225,8*23\x0D\x0A"};
Yes
GPS module will return message
"$PMTK001,225,3*35\x0D\x0A"
if command is accepted.
Request a GPS
position data
No
Yes
Issue any byte to get
GPS position data
No
Set GPS to normal
operation mode?
Change GPS back to
AlwaysLocate mode
Yes
Issue any byte to GPS
and wait it awake
No
Set GPS to normal
operation mode
unsigned char NormalMode[] =
{"$PMTK225,0*2B\x0D\x0A"};
End
GPS is in normal mode
5.4 Data logger
The GPS module has internal flash memory for logging GPS data. The configurations
Page 12/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
include time interval, distance, speed, logging mode, and … etc. For more information, please
contact us.
6
Pin assignment and descriptions
Table 6-1 Pin descriptions
Pin # Name
Type Description
1
NC
Not connected
2
NC
Not connected
3
TX
O
Serial output (Default NMEA)
4
RX
I
Serial input (Default NMEA)
5
NC
6
VCC
P
DC supply voltage
7
GND
P
Ground
8
NC
Not connected
9
NC
Not connected
Note
Not connected
Reset input, active low.
10
/RESET
I
11
V_BCKP
P
GPS module has internal power-on reset circuit, user can
leave this pin floating.
Backup battery supply voltage
This pin must be powered to enable the module.
1
Page 13/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
12
NC
Not connected
13
GND
P
Ground
14
GND
P
Ground
15
GND
P
Ground
16
RF_IN
I
GPS RF signal input
17
GND
P
Ground
18
VCC_RF
O
Output voltage for active antenna
19
V_ANT
I
Antenna bias voltage
20
NC
Not connected
21
NC
Not connected
22
NC
Not connected
23
NC
Not connected
24
NC
Not connected
25
NC
Not connected
26
NC
Not connected
27
NC
Not connected
28
TIMEPULSE O
Time pulse (1PPS, default 100 ms pulse/sec when 3D fix is
available)
2
<Note>
1. In order to get the advantage of hybrid ephemeris prediction, this pin must be always powered during the period
of effective ephemeris prediction.
2.
VCC_RF does not have short circuit protection.
Page 14/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
7
DC & Temperature characteristics
7.1 Absolute maximum ratings
Parameter
Symbol
Ratings
Units
VCC
4.3
V
Input Backup Battery Voltage
V_BCKP
4.3
V
Operating Temperature Range
Topr
-40 ~ 85
℃
Storage Temperature Range
Tstg
-40 ~ 85
℃
Input Voltage
7.2 DC Electrical characteristics
Parameter
Min.
Typ.
Max.
Units
VCC
3.0
3.3
4.3
V
Input Backup Battery Voltage
V_BCKP
2.0
4.3
V
VCC_RF Output Voltage
VCC_RF
Input Voltage
Symbol
Conditions
VCC
V
VCC = 3.3V,
Supply Current
Iss
w/o active antenna,
Peak
Acquisition
Tracking
26
18(2)
mA
mA
mA
Standby
170
uA
VCC = 0V
6
uA
87(1)
Backup Battery Current
Ibat
High Level Input Voltage
VI H
2.0
3.6
V
Low Level Input Voltage
VI L
-0.3
0.8
V
High Level Input Current
IIH
no pull-up or down
-1
1
uA
Low Level Input Current
IIL
no pull-up or down
-1
1
uA
High Level Output Voltage
VOH
Low Level Output Voltage
VOL
High Level Output Current
IOH
2
mA
Low Level Output Current
IOL
2
mA
2.4
V
0.4
V
Note 1. This happens when downloading AGPS data to MC-1722.
Note 2. Measured when position fix (1Hz) is available, input voltage is 3.3V and the function of self-generated ephemeris
prediction is inactive.
7.3 Temperature characteristics
Parameter
Symbol
Min.
Typ.
Max.
Units
Operating Temperature
Topr
-40
-
85
℃
Storage Temperature
Tstg
-40
25
85
℃
Page 15/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
8
Mechanical specification
8.1 Outline dimensions
8.2 Recommended land pattern dimensions
Page 16/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
9
Reel Packing information
Page 17/18
© 2011 LOCOSYS Technology Inc.
LOCOSYS Technology Inc.
20F.-13, No.79, Sec. 1, Xintai 5th Rd.,
Xizhi City, Taipei County 221, Taiwan
℡ 886-2-8698-3698
886-2-8698-3699
www.locosystech.com/
Document change list
Revision 1.0
First release on November 2, 2011.
Page 18/18
© 2011 LOCOSYS Technology Inc.