data logger sketch
Merge remote-tracking branch 'upstream/master'
Merge pull request #7 from saurabh-ar/master

Added Adafruit SD card sample
Added SD card logging
bug fix: sprintf argument was wrong
Merge remote-tracking branch 'upstream/master'
added sd card modified sketch
Merge pull request #8 from pixma/master

SD sample sketch changed.
Merge remote-tracking branch 'upstream/master'
fixed discontinuous data logging problem