file numbering + mode switch query

[extreme2themax]

I have started to collect data on my nano, but was wondering about the file naming conventions.  I don't download the data after every session, so occasionally have 2 sessions on the same day, and maybe just download 5 sessions at the end of the week.

One time I had driven in the morning for about an hour, and later in the afternoon went cycling for 2h.  On that occasion the data was all stored to a single file, so based on that I assumed that all the data was just added to whichever day the unit was turned on at

But then another time, the file name had 0000 for the date part of the filename, and when I uploaded it , i could see data from 3 days earlier also attached in the same filename.

Are there specific rules as to how the files should be created?

2nd question , is it OK to switch between modes while the unit is switched on , I have not tried it , but was thinking it might be better to let the GPS get steady before switching to log mode, so far I have always just switched on while in log mode and left it

Oh, also made a little timelapse of my nano build and uploaded it if other are curious,  https://youtu.be/6x_5pi7v65k

[Mat Schaffer]

Love the timelapse!

I'm sure folks on the list (Rob maybe?) will have some more ideas about the hardware (I'm a server guy myself), but I don't think I've seen the 0000 file on mine. I suspect it has something to do with writing a file before the GPS time is available. But afaik it's not supposed to record data until it has good GPS.

I switch mine on in log mode and switch between modes all the time and haven't noticed a problem yet.

Typically I won't see it recording (red LED on, SD card blinking on write) until GPS has a good link. Or if I go through a tunnel I'll see it stop recording when it loses GPS.

-Mat

matschaffer.com

[Jan Helebrant]

Hi,

following my experience the zeros in the filename are in the case bGeigie writes the file without having current time/date data (probably from the GPS). Otherwise the file always contains the day

for example:

24080811.LOG

where 2408 is device number and the data were measured 8.11. 2017 - thus 0811.

My only problem is that the filename does not contain year so you can have problem if you measured with the same device on the same day and then try to put the file in one folder. But we have separated folders for each year so problem solved.

One time I had driven in the morning for about an hour, and later in the afternoon went cycling for 2h.  On that occasion the data was all stored to a single file, so based on that I assumed that all the data was just added to whichever day the unit was turned on at

If the device was not switched off and on again (this writes a new header in the LOG file so you can find where the new measurement begins) then you have the car and bike data in the same file.

I am facing this problem really often (mixed car/walk/bike trips).

I am using QGIS + Safecast plugin to solve this:

https://opengeolabs.github.io/qgis-safecast-plugin/user-manual.html#delete-measured-points

you simply load the LOG file (for example 24080811.LOG), add background map and look on your data. Then you select and delete bike data and save the rest as for example 24080811_car.LOG. Then load again 24080811.LOG, select and delete car data and save the result as 24080811_bike.LOG. This prevents you from overwriting the original file.

Jan