[PLUG] Arduino issue

[Denis Heidtmann]

I am developing a logging program.  The Arduino is a Uno R2.  It has an
ATAfruit SD shield w/ RTC.  For testing purposes I record data once per
second.  When I am finished testing I will be taking data much less
frequently, although there might be random times when a few data points are
only one second apart.

I convert the data ( a long; two strings, 3 ints) to a string in CSV
format.  But often not all the data gets assembled into the string.  It
seems that the += operation does not append the string to be added.

I removed the references to the SD card and the failures went away, or so
it seems.  I need to run it for a longer time, but before I removed the SD
stuff the problem showed up in two to  four seconds.  So let's assume that
the issue was the SD writing.

How might I go about exploring this issue?

Thanks,
-Denis