3.2
Data Format
Data is written to files in comma separated text format starting with the file header information and
followed by event data entries. Table 2 lists the valid header tags, although not all tags may occur in
the header. Each data line contains a time entry and the raw accelerometer sensor readings from the X,
Y, and Z axes. The time entry is seconds elapsed from the start time recorded in the header. Add the
elapsed time to the start time to determine the complete date and time of the sample.
The last line of the final data file records the reason for the termination, such as “shutdown: switched
off”, “shutdown: low battery”, “shutdown: max files exceeded”, “shutdown: vbus disconnect”, or
“connected to computer”. The line is designated as a comment with a semicolon (“;”).
Table 2: Data File Header Tags
Tag
Description
Deadband
A new sample from the sensor must exceed the last reading by the
deadband value
DeadbandTimeout
The period in seconds when a sample is recorded regardless of the
deadband setting
Headers
The names of each column of data in the file
SampleRate
Rate at which data is recorded to the microSD card
Start_Time
The current time when the data file was created
Temperature
Not supported on X16-1D, reports -999
Title
The name of the USB Accelerometer X16-1D unit and sensor type
Vbat
Battery voltage measured at the file start time
Version
The version control information of the firmware, including unique
serial number
Gulf Coast Data Concepts
Page 17
X16-1D, Rev B
Figure 19: Example Data File
;Title, http://www.gcdataconcepts.com, x16-1d, ADXL345
;Version, 1110, Build date, Dec 30 2015, SN:CCDC4016131F31B
;Start_time, 2016-01-04, 10:25:14.000
;Temperature, -999.00, deg C, Vbat, 1444, mv
;SampleRate, 100,Hz
;Deadband, 0, counts
;DeadbandTimeout, 0,sec
;Headers, time,Ax,Ay,Az
0.003,799,650,-1773
0.013,805,661,-1808
0.023,766,687,-1844
0.033,790,670,-1818
0.042,801,663,-1808
0.052,769,657,-1786
0.062,790,683,-1795
0.072,813,719,-1853
0.081,824,670,-1784
