GPS module control commands

I used to find information that I could not find.

 

Using appropriate initialization statements and control commands can greatly speed up search and reduce power consumption.

It is used when designing low-power instruments.

Currently, the design of the instrument is measured on foot, and the movement speed is very slow. Therefore, the update time is changed from 1 second to 10 seconds, which can reduce power consumption. After all, battery devices can be used, the power supply is still very tight. If GPS is used on high-speed vehicles, the update time is 0.1 seconds.

========================================================== ==========

$ Psrf104 reset command (host output ):
$ Psrf104, <latitude Offset>, <longitude Offset>, and Shift>, <clock compensation>, <GPS second/week>, <GPS week>, <channel>, <reset and select
Item> * <checksum> <CR> <LF>
The <latitude Offset> range is 90 to-90 degrees. The default value of GPS positioning is 0.
<Longitude Offset> the range is 180 to-180 degrees. The default value of GPS positioning is 0.
<Height Offset> the default value of GPS positioning accuracy is 0.
<Clock compensation> when the value is 0, the data stored last time is called. The default value is 96000.
The default value of <GPS seconds/week> is 237759.
<GPS week> this parameter may not be very useful. The data output from the serial port ** is 922.
<Channel> the channel used by GPS, ranging from 0 to 12. The default value is 12.
<Reset option> 1 = hot start, all data are valid; 2 = warm start, calendar clear 3 = warm start, calendar clear and load initialization data
4 = cold start, clear all data in the memory 8 = clear all data in the memory and reset the GPS to the factory status.
Example: Hot Start, warm start, and cold start
$ Psrf104, 237759,922, * 2B <CR> <LF>
$ Psrf104, 237759,922, * 28 <CR> <LF>
$ Psrf104, 237759,922, * 2E <CR> <LF>

 

========================================================== ========================================================== ===

 

Kay lide's ultimate exploration of searching for stars within a few seconds (other methods may be wrong)

Original Author: coolrunner

There is an article "about slow searching and star jumping in different versions of Kay lide". This article discusses the solution. I feel that the method for modifying com4 is correct, but it is wrong to modify 96000 because 96000 is time compensation, not the GPS baud rate. Therefore, this method only improves when the COM port is incorrect, and does not significantly improve the slow search and hop star rates.

Me
Provide a final solution for your reference (after I modify it, you can locate it within almost 3 seconds after it is started for the first time or every time it is started later): Use uedit to enable it in hexadecimal mode.
Pnavi. dll or navione. dll (different programs opened in different Kay lide versions), search for $ psrf104 (that is, modify the same location of 96000 in the previous article), you will see
Commands used to start GPS at Kay lide
"$ Psrf104, 237759,922, * 2E <CR> <LF>", 4 * 2E indicates the first time
When GPS is started, it is cold-start, but I suspect that Kelly uses cold-start every time GPS is started, so the search speed is very slow and the quickgps data will be cleared. Therefore, I will
Change to hot start, change the aforementioned 4 * 2E to 1 * 2B, and save the file. OK! Success!

After trying out the modified Kay lide, souxing's positioning speed is extremely fast, almost within two or three seconds (remember to update quick GPS data before the first start ).

Another
Besides, my DIY Wm
Some GPS parameters are adjusted in 6.1rom, mainly to reduce the size of the GPS buffer and change the poll interval to 100 milliseconds (that is, 10 times per second). This modification may consume more power, but it does make sense, especially
It can navigate to the intersection in time, because I understand that the processing of GPS data by the navigation software may not be completely synchronized with the frequency of receiving data by the GPS hardware, therefore, set the poll interval to read time per second.
Theoretically speaking, but in fact, data lags behind due to data loss, CPU speed, software design, and other reasons), uses quickgps, but does not use agps (I personally think agps is of little significance), and Port
The rate is changed to 115200 (many people say this change is meaningless, but it still feels a little different, or it may only be a feeling, but there is no scientific basis) for your reference:

[HKEY_LOCAL_MACHINE/system/CurrentControlSet/GPS intermediate driver/multiplexer]
"Maxbuffersize" = DWORD: 200

[HKEY_LOCAL_MACHINE/system/CurrentControlSet/GPS intermediate driver/Drivers]
"Sleeponnodata" = DWORD: 64
"Outputbuffersize" = DWORD: 100
"Inputbuffersize" = DWORD: 100

[HKEY_LOCAL_MACHINE/system/CurrentControlSet/GPS intermediate driver/Drivers/gpsonedevice]
"Pollinterval" = DWORD: 64

[HKEY_LOCAL_MACHINE/software/Microsoft/Windows/CurrentVersion/explorer]
"Gpsbaud" = "115200"

[HKEY_LOCAL_MACHINE/software/HTC/supl agps]
"Gpsmode" = DWORD: 0
"Enableagps" = DWORD: 0

In addition, my GPS settings for Kay lide are com4, 115200

Attachment for Kay lide P0902-T3106-17B1J04 version, other versions do not download, Please modify on your own.

The principle of this method is to modify the GPS commands in the navigation software. It should be applicable to other navigation software, such as flexibility maps.

 

========================================================== ========================================================== ===

 

For more information, see sirf's NMEA reference manual.

The following sections are excerpted for your reference:

104-llanavigationinitialization

This command is used to cause a restart of
Extends er, and to specify the type of restart. Optionally, it may also
Initialize position (in lattitude, longpolling, and altitude), clock
Drift, gps time of week and GPS week number.
This
Enables the explorer to search for the correct satellite signals at
Correct signal parameters. Correct initialization parameters enable
Aggreger to quickly acquire signals.

 

150-oktosend

This message is sent out during power-saving modes
Such as tricklepowertm and push-to-fixtm to indicate when the specified er
Is ready to receive messages or when it is going into low-power mode.
When power is restored, it is the first message sent, and when power is
Going to be writable Ced, it is the last message sent.
Table 1-15 contains the values for the following examples:
1. oktosend
$ Psrf150, 1 * 3f

2. Not oktosend
$ Psrf150, 0 * 3E

 

Advanced Power Management (APM) Considerations for ssiii

Advanced Power Management-message id 53

Used to implement advanced power management (APM). APM will not engage
All information is stored.
Example:
The following example sets the operator er to operate in APM mode with 0 cycles before
Sleep (continuous operation), 20 seconds between fixes, 50% duty cycle, a time
Between fixes priority, and no preference for accuracy.
The A0A2000C-Start sequence and payload length.
3501001400030700000a0100-payload
005fb0b3-message checksum and end sequence

For details, see 2-3 pages in the manual,

Set tricklepower parameters-Message ID 151

Table 2-36 contains the input values for the following example:
Sets the operator into low power modes.
Example: Set receiver ER into tricklepower at 1Hz update and 200 MS on-time.
The A0A20009-Start sequence and payload length.
97000000c8000000c8-payload
0227b0b3-message checksum and end sequence

For details, see 2-19 pages in the instruction manual,

Push-to-fix

In this mode the specified er will turn on every cycle period to perform a system update
Consisting of an RTC calibration and satellite ephemeris data collection if required
(I. e., a new satellite has become visible) as well as all software tasks to support snap
Start in the event of an NMI (non-Maskable Interrupt). ephemeris collection time in
General takes 18 to 36 seconds. If ephemeris data is not required then the system will
Re-calibrate and shut down. In either case, the amount of time the specified er remains off
Will be in proportion to how long it stayed on:
Off period = on period * (1-duty cycle)
Duty Cycle
The off period has a possible range between 10 and 7200 seconds. The default is 1800
Seconds. Push-to-fix cycle period is set using message mid 167.

For more information, see 2-20.

Set low power acquisition parameters-Message ID 167

For details, see 2-23.