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doc:appunti:hardware:gps_logger_i_blue_747 [2009/01/20 23:12] – external edit 127.0.0.1doc:appunti:hardware:gps_logger_i_blue_747 [2019/10/11 17:47] (current) – [Week Rollover Bug] niccolo
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 ====== MTKBabel ====== ====== MTKBabel ======
  
-:!: **NEW!** MTKBabel is now hosted on **[[https://sourceforge.net/projects/mtkbabel|Sourceforge]]**!+MTKBabel is hosted on **[[https://sourceforge.net/projects/mtkbabel|Sourceforge]]**!
  
 **MTKBabel** is a Perl program to operate the **i-Blue 747 GPS data logger**. It should work also with other GPS devices based on the **MediaTek MTK** chipset. Starting with version **0.7** it offers also support for the **Holux M-241** data logger. It is free software released under the GPL license. **MTKBabel** is a Perl program to operate the **i-Blue 747 GPS data logger**. It should work also with other GPS devices based on the **MediaTek MTK** chipset. Starting with version **0.7** it offers also support for the **Holux M-241** data logger. It is free software released under the GPL license.
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 Options: Options:
     -a                       Read all the log memory (overlapped data)     -a                       Read all the log memory (overlapped data)
-    -b filename.bin          Do not read data from a GPS device, but rather read a +    -b filename.bin          Don't read data from a GPS device, but rather read 
-                             previously saved .bin file. Ignore -f option +                             a previously saved .bin file. Ignore -f option 
-    -c                       Create a gpx file with tracks and waypoints+    -c                       Create a GPX file with tracks and waypoints
     -d debug_level           Debug level: 0..7     -d debug_level           Debug level: 0..7
     -E                       Erase data log memory     -E                       Erase data log memory
     -f filename              Base name for saved files (.bin and .gpx)     -f filename              Base name for saved files (.bin and .gpx)
     -h                       Print this message and exit     -h                       Print this message and exit
-    -i                       Ignore some error conditions and try to extract data +    -i                       Ignore some error conditions, try to extract data 
-    -l {on|off}              Turn loggin ON/OFF+    -l {on|off}              Turn logging ON/OFF
     -m {stop|overlap}        Set STOP/OVERLAP recording method on memory full     -m {stop|overlap}        Set STOP/OVERLAP recording method on memory full
-    -o log_format            Enable or disable log fields (FIELD1,-FIELD2,...), available fields:+    -o log_format            Enable or disable log fields (FIELD1,-FIELD2,...), 
 +                             available fields:
                              UTC,VALID,LATITUDE,LONGITUDE,HEIGHT,SPEED,HEADING,DSTA,DAGE,PDOP,HDOP,VDOP                              UTC,VALID,LATITUDE,LONGITUDE,HEIGHT,SPEED,HEADING,DSTA,DAGE,PDOP,HDOP,VDOP
                              NSAT,SID,ELEVATION,AZIMUTH,SNR,RCR,MILLISECOND,DISTANCE                              NSAT,SID,ELEVATION,AZIMUTH,SNR,RCR,MILLISECOND,DISTANCE
     -p port                  Communication port, default: /dev/ttyUSB0     -p port                  Communication port, default: /dev/ttyUSB0
-    -R                       Recover from disabled log: erase data and reset recording criteria+    -R                       Recover from disabled log: erase data and reset 
 +                             recording criteria
     -r time:distance:speed   Set logging criteria (zero to disable):     -r time:distance:speed   Set logging criteria (zero to disable):
-                             every 1-999 seconds, every 10-9999 meters, over 10-999 km/h+                             every 0.10-9999999.90 seconds, every 0.10-9999999.90 
 +                             meters, over 0.10-9999999.90 km/h
     -s speed                 Serial port speed, default 115200 baud     -s speed                 Serial port speed, default 115200 baud
-    -t                       Create a gpx file with tracks+    -t                       Create a GPX file with tracks
     -v                       Print MTKBabel version and exit     -v                       Print MTKBabel version and exit
-    -w                       Create a gpx file with waypoints+    -w                       Create a GPX file with waypoints 
 +    -x                       Force reading Holux format
  
 Example: Example:
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 If you encounter some problems, please run the program with the ''**-d 7**'' option and write me a mail with the output. You will find my address in the program itself. If you encounter some problems, please run the program with the ''**-d 7**'' option and write me a mail with the output. You will find my address in the program itself.
  
-==== Credits ====+===== Weeks Rollover Bug ===== 
 + 
 +It turned out that several GPS based on the MTK chipset are affected by a **Weeks Rollover Bug**. You discover that your device is affected by the bug because the GPX files you save from it, will have a **timestamp badly in the past**. 
 + 
 +Actually I have two i-Blue 747 GPS data loggers. The older one is a **Model ID 001B**, which has already manifested the problem: today is **2019-10-10**, but GPX points logged have a timestamp of **2000-02-24**. If you do the math, you can find that there is a **difference of exactly 1024 weeks**. This means that the device internally stores timestamps using a **weeks counter of only 10 bits**. So exactly 1024 weeks after its //EPOCH// (the begin of the time it can handle), the timestamps rolls-back of that amount of time. 
 + 
 +The other logger of mine is a **Model ID 001D**, which instead is still recording correct timestamps today. I suspect that the weeks counter is nevertheless 10 bits, and just the hard-coded EPOCH is more recent. So the bug is **just to come in the near future**. 
 + 
 +  * **[[https://www.theverge.com/2019/3/8/18255847/gps-week-rollover-issue-2019-garmin-tomtom-devices-affected|Older GPS devices are facing their own mini Y2K bug next month]]** 
 +  * **[[https://github.com/gpsbabel/gpsbabel/issues/349|Holux M-241 gps weeks rollover issue]]** 
 +===== Credits =====
  
 I wish to thank all the people behind the **[[http://sourceforge.net/projects/bt747/|BT747 project]]**: everything I made is derived from their work. I wish to thank all the people behind the **[[http://sourceforge.net/projects/bt747/|BT747 project]]**: everything I made is derived from their work.
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 blacklist pegasus blacklist pegasus
 </file> </file>
 +
 +====== i-Blue 747 A+ with Linux ======
 +
 +It seems that the new model **747 A+** (66 channels, 125000 way points storage space) requires the kernel module **cdc_acm** provided by **Linux Kernel 2.6.29**. Once connected the device is detected as **''/dev/ttyACM0''**.
  
 ====== Logging ====== ====== Logging ======
doc/appunti/hardware/gps_logger_i_blue_747.1232489546.txt.gz · Last modified: (external edit)