GPS_Logger_v1
Kenji Arai.
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Keyword: GPS, SD Card, LCD, Logger, File system, Analog input, RTC
Control Program
Reference
Function
Every one seconds, GPS data (RMC & GAA) and five analog inputs are logged in SD-CARD.
1. File name creates from time (since 1970/1/1) of RTC
2. Condition shows on Text LCD
3. DEBUG infromation sends PC via USB Serial
Hardware Configlation
------- GPS Receiver --------
SZP950T (only Japanese explanation) SiRF3 TTL level Interface
------- Pin Assignment -----
I have changed pin assignment from previous projects.
This is new "Pin Assignment".
Software
------- Known BUG ---------
Just after Recorde Switch activation, the program starts a file open action then takes long time.
In parallel, GPS sends data stream constantly and some data are missing.
You can see the data (PC Com monitor via USB serial for DEBUG) as follows.
---> Measure for this bug
It's not only 1st line of data problem but also seems like buffer overflow problem and affect all of saved data .
I cannot solve the problem itself at this moment and only tentative solution is below program.
Every time, clear the data buffer (MsgBuf_RMC &GGA) before copy from msg buffer. This makes no problem for recorded data.
if (strncmp(msg, "$GPRMC",6) == 0) {
for (int i=0; i<BSIZ ; MsgBuf_RMC[i++]=0); // Clear buffer
for (int i=0; msg[i] != 0; i++) { // Copy msg to RMC buffer
MsgBuf_RMC[i] = msg[i];
}
gps_dat = RMC; How to use recorded data
Followings are sequence to use the GPS logger.
1. After data collection into SD card, you can read the text file from SD card to your PC.
2. Convert the text file to waypoint, tracks and routes information using GPSBabel software.
3. Just double clicks the converted file then you can see the result on “Google Earth”.
If you have not installed the software, please check following links.
2. Google Earth -> Free Download
Revision
April 17th, 2010 Create this page
April 18th, 2010 Updated the infromation
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