Garbage value written in .csv file by ADC
One really obvious bug is that your format string specifies 7 data fields, but you're only supplying 6 additional arguments. sprintf() (and friends) will happily read whatever garbage is on the stack and put it into any unspecified fields.

Also, note that you aren't showing us the contents of the actual CSV file; you're showing us the result of passing the file through some other program, which is applying its own interpretation to what it's finding there.