發表時間:5/26/2001 12:13:02 PM 作者: chehui 時間: 2001-7-23 01:29 標題: 回覆: GPS在PALM的應用(from Larry's DIY 舊版討論區) 討論主題:Ref Spec.
主題發表人:fox
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如果您拆開 Street Finder for Palm III, 您會發現
RTC 與 32.768 Khz X'tal 及 Backup Battery 沒裝.
因為如果搭配 PDA or PC 使用, 若程式特別設計過,
就可以省掉這個部分.
但如果使用其他程式未去初始化 GPS, 很可能您要 5-8 min. 才能定位.
請參考
*** GPSAPI ***
3.3 Initializing the GPS Engine GPS Engine
Once the API session is successfully created, the GPS Receiver Engine
must be initialized. Four functions are provided
although only one or two may be necessary depending on available
information.
The GPS Receiver Engine should be initialized with the correct UTC time
and date. The InitTime() function (in binary mode)
or the gapiSendCommand function (in NMEA mode) can be used after the
gapiSetDeviceConfig() and OpenGPS() function
to ensure correct time initialization of the GPS Receiver Engine.
If time is initialized correctly and approximate initial position is known, then
acquisition of a solution can usually be obtained
in less than one minute. The InitPos() function (in binary mode) or the
gapiSendCommand() function (in NMEA mode) is
used to initialize the position if more than several hundred miles off.
Approximate position for the function is in degrees of
latitude, longitude and meters for altitude.
...
If no information (UTC time and approximate initial position information) is
available, the ColdStart() function (in binary
mode) or the gapiSendCommand() function (in NMEA mode) can be used.
This function takes no parameters, but it is the
slowest means to obtain position data. An average of 8 minutes is typical
from the time the command is sent until a
solution is obtained.
Conexant’s Scorpio device is a custom, 12-channel Baseband Processor
(BP)
with an embedded Advanced Architecture Microprocessor 2-8 (AAMP2-8)
and
multifunction Input/Output (I/O).