SD card available space

[scott2b]

Can we know how much space is available on the SD card? If so, we should transmit this information, with possible special handling of logfiles - such as deleting old data

[scott2b]

see https://github.com/greiman/SdFat/blob/master/SdFat/examples/VolumeFreeSpace/VolumeFreeSpace.ino

[scott2b]

Note, getting the available space on the card has a fair amount of latency to it. We don't want to check the available space, for example, in every loop. Check after n loops or n amount of time .. or better yet, after n writes and track the amount of data we are writing so as to keep a fairly accurate account of what is available on the card without constantly checking it.