csv arrays

[aaronik19]

Dear Friends,

Currently I am making a datalogging system and to save data on SD Card I was going to us the following structure. First I create a 2D array such as:

[temtronic]

If you're going to import into Excel, you'll need a cr,lf after 'status'. This allows Excel to automatically enter the data into the correct rows and columns.

[aaronik19]

thanks temtronic, but the idea is good? on the SD Card, can I say that 16MB card has 16384000000 bytes (1024*16000000 = 16384000000), so it can holds more than 8192000000 integers(values) since integer in 16-bit takes 2 bytes (hope that I know this good)?

[temtronic]

Not quite...

16MBytes is the raw unformatted data storage for the card. Depending on how it is formatted you can easily lose 5-10% of the bytes ! Even more depends on the actual file type(FAT16,FAT32,NTFS,custom).If you're always dealing with small files of known data, it's better to format using smaller clusters to maximize the storage capability of the drive.

All this should be covered in any decent book on 'PC file formats'.

And...if using CSV formatted data, every "," (comma) which is the data separator takes up one byte of storage.In your example,if the data are all 16 bit values ,you'll need 5 *2 +6 *1 + 2 bytes per 'record' or 18 bytes total.Not to sure how you're encoding the date and time into 16 bits though.And HOW you decode the data in the PC is another matter.
It's a lot easier to just save the date and time as string data so that Excell can automatically load into a spreadsheet for instant analysis.

Also be aware that to some of us, 'integer' IS an 8 bit value( a Byte).What the variable actually holds depends on the operating system, program be used, and programmers preferences.