Gulf Coast Data Concepts X16-1D User manual

X16-1D
USB Accelerometer
Data Logger
User Manual
Document Revision: Rev B
Firmware Version: 111
Date: March 22, 2 16

Table of Contents
1 Introduction..........................................................................................................................................1
1.1 About This Manual..................................................................................................................1
1.2 Document Conventions............................................................................................................1
1.3 Appendix..................................................................................................................................1
1.4 Product ummary.....................................................................................................................2
1.5 Feature List..............................................................................................................................2
1.6 Items Included with X16-1D...................................................................................................3
1.6.1 ingle Unit Purchase..........................................................................................................3
1.6.2 5 Unit Kit...........................................................................................................................3
1.7 Component Names...................................................................................................................4
1.8 Quick tart Guide....................................................................................................................5
2 Operation..............................................................................................................................................8
2.1 U B Interface...........................................................................................................................8
2.2 Memory Card...........................................................................................................................8
2.3 Battery......................................................................................................................................8
2.4 etting The RTC.......................................................................................................................9
2.5 tatus Indicators.....................................................................................................................11
2.6 ystem Configuration Options...............................................................................................11
2.6.1 deadband..........................................................................................................................12
2.6.2 deadbandtimeout..............................................................................................................13
2.6.3 dwell.................................................................................................................................13
2.6.4 microres............................................................................................................................14
2.6.5 rebootondisconnect..........................................................................................................14
2.6.6 samplesperfile..................................................................................................................14
2.6.7 samplerate........................................................................................................................14
2.6.8 starttime and stoptime......................................................................................................14
2.6.9 stoponvusb.......................................................................................................................15
2.6.10 statusindicators.................................................................................................................15
2.7 Example Configuration Files.................................................................................................15
2.7.1 Example A........................................................................................................................15
2.7.2 Example B........................................................................................................................15
2.7.3 Example C........................................................................................................................16
3 Data Interpretation.............................................................................................................................16
3.1 Data Files...............................................................................................................................16
3.2 Data Format...........................................................................................................................17
3.3 Data Conversion.....................................................................................................................18
4 ystem Details...................................................................................................................................18
4.1 ensor.....................................................................................................................................18
4.1.1 ensor pecial Features...................................................................................................19
4.2 Operating and torage Conditions ........................................................................................20
4.3 Dimensions............................................................................................................................20
5 Troubleshooting.................................................................................................................................21
6 Appendix............................................................................................................................................23
6.1 What is an Accelerometer......................................................................................................23
A

6.2 Using “R” to Analyze Data....................................................................................................25
6.2.1 What is “R”......................................................................................................................25
6.2.2 Introduction to R Commands...........................................................................................26
6.2.3 Online Resources for R....................................................................................................27
6.2.4 Example cripts in R.......................................................................................................28
Index of Figures
Figure 1: X16-1D Data Logger..................................................................................................................2
Figure 2: X16-1D and Accessories............................................................................................................3
Figure 3: 5 Unit kit of Loggers..................................................................................................................3
Figure 4: X16-1D Data Logger Components.............................................................................................4
Figure 5: Exploded View of the X16-1D..................................................................................................4
Figure 6: Installing Battery........................................................................................................................5
Figure 7: Connecting to PC........................................................................................................................5
Figure 8: Editing Config.txt File................................................................................................................6
Figure 9: tarting the X16-1D...................................................................................................................7
Figure 10: ensor Orientation....................................................................................................................7
Figure 11: Expected Battery Life...............................................................................................................9
Figure 12: Example Time Entry in time.txt File.....................................................................................10
Figure 13: LED tatus Indicators............................................................................................................11
Figure 14: Graphical Illustration of the Deadband Feature....................................................................13
Figure 15: Graphical Illustration of the Dwell Feature...........................................................................13
Figure 16: Configuration File Example A..............................................................................................15
Figure 17: Configuration File Example B..............................................................................................15
Figure 18: Configuration File Example C..............................................................................................16
Figure 19: Example Data File.................................................................................................................17
Figure 20: 800Hz sample configuration.................................................................................................20
Figure 21: Enclosure Dimensions...........................................................................................................20
Figure 22: pring-mass Accelerometer...................................................................................................23
Figure 23: implified MEM Accelerometer Design (L) and Actual MEM Accelerometer (R).........24
Figure 24: R Command Line Interface ..................................................................................................25
Figure 25: R tudio Interface ..................................................................................................................26
Index of Tables
Table 1: Configuration File Tags and Descriptions..................................................................................12
Table 2: Data File Header Tags................................................................................................................17
Table 3: Example Data Conversion.........................................................................................................18
Table 4: Accelerometer ensor Characteristics........................................................................................19
Table 5: Operating and torage Conditions.............................................................................................20
B

1 Introduction
1.1 About This Manual
Thank you for purchasing the X16-1D accelerometer data logger. Gulf Coast Data Concepts spent
considerable efforts developing an easy to use data logger for the scientific researcher, student, or
hobbyist. Please read this manual to understand the operation and capabilities of the X16-1D. If the
logger fails to operate as expected, please refer to the troubleshooting guide (page 21).
1.2 Document Conventions
The quick start guide in section 1.8 provides a basic summary of operation to begin using the X16-1D
data logger. This user manual continues into further details of configurations and capabilities starting
in section 2. Each section also presents relevant tips and warnings to help the user.
This icon indicates a helpful tip that may enhance the performance of the logger or aide in
the application of the logger.
This icon indicates a warning, restriction, or limitation that the user should be aware of
regarding the logger operation.
1.3 Appendix
The appendices to this document include several educational discussions regarding accelerometers
(section 6.1) as well as software and analysis procedures (section 6.2). These short discussions will
help new users learn about the X16-1D and how to use the data.
Gulf Coast Data Concepts Page 1 X16-1D, Rev B

1.4 Product Summary
The X16-1D is a low cost and compact self-recording accelerometer data logger. Data from the digital
3-axis accelerometer sensor is time stamped using a real time clock and stored to a micro D card in
simple text format. When connected via the U B to a personal computer, the X16-1D appears as a
standard mass storage device containing the comma delimited data files and the user setup file. The
X16-1D is powered from a replaceable AA type alkaline battery (or LR6).
1.5 Feature List
•3-axis ±16g accelerometer
•16-bit resolution
•User selectable sample rate of 12, 25, 50, 100, 200, 400 Hertz
•Finite Impulse Response filter
•Accurate time stamped data using Real Time Clock (RTC)
•Convenient on/off button
•Data recorded to a removable micro D card (8GB included)
•Easily readable comma separated text data files
•Data transfer compatible with Windows or Linux via Universal erial Bus (U B) interface (no
special software required)
•Uses a standard replaceable “AA” type alkaline battery
•Weight 2oz (55g) with alkaline battery
•ize 1x1x4.1 inch (26x26x104 mm)
Gulf Coast Data Concepts Page 2 X16-1D, Rev B
Figure 1: X16-1D Data Logger

1.6 Items Included with X16-1D
1.6.1 Single Unit Purchase
The X16-1D is packaged with the logger, a USB extender cable, a screwdriver, and an AA
alkaline batter .
1.6.2 5 Unit Kit
A kit includes 5 X16-1D loggers, a USB extender cable, and a screwdriver. Batteries are not
included with kits.
Gulf Coast Data Concepts Page 3 X16-1D, Rev B
Figure 2: X16-1D and Accessories
Figure 3: 5 Unit kit of Loggers

1.7 Component Names
A Type-A U B connector I Enclosure top
B Blue LED status indicator J Enclosure bottom
C Red LED data indicator K Enclosure cap
D AA Battery holder L Enclosure hinge
E Positive terminal M #6-32 3/4” screw
F Negative terminal N #6 nut
G On/Off button O ADXL345 sensor
H Micro D card (under circuit board)
Gulf Coast Data Concepts Page 4 X16-1D, Rev B
Figure 4: X16-1D Data Logger Components
A
I
B
C
D
H
E
K
G
F
J
M
N
O
L
Figure 5: Exploded View of the X16-1D
0.75" Length
#6-32 Machine Screw
PCB Enclos re
(Top)
PCB Enclos re
(Cap)
Printed Circ it Board
PCB Enclos re
(Bottom)
#6-32 Hex N t

1.8 Quick Start Guide
The X16-1D is a simple, economical solution to capture continuous motion data and quickly deliver the
information for analysis. The following instructions outline the steps to begin using the X16-1D.
Configuration settings and mounting methods will depend on the particular application.
tep 1: Disassemble the enclosure by unscrewing the #6 machine screw and opening the parts
like a clam shell. Place an AA type battery into the battery holder with the positive
battery terminal facing away from the U B connector. Reassemble the enclosure.
tep 2: Plug the X16-1D into a computer and allow the computer operating system to register
the device as a Mass torage Device. Notice that the logger will mount with a drive
label using the last digits of the serial number.
Gulf Coast Data Concepts Page 5 X16-1D, Rev B
Figure 6: Installing Battery
Figure 7: Connecting to PC

tep 3: Configure the X16-1D by editing the appropriate tags in the config.txt file using a
simple text editor. In Windows, do not use Notepad as the editor does not terminate new
lines properly. GCDC recommends Windows Wordpad or Notepad++ to edit the
config.txt file. Refer to section 2.6 for a complete list of configuration options.
tep 4: If necessary, initialize the RTC clock by creating a time.txt file (see section 2.4). Once
the time.txt file is saved, immediately unplug the logger to start the initialization
process. The logger will load the time.txt file, initialize the clock, and delete the time.txt
file. Initializing the RTC ensures the data files include the correct year, month, and day
and that the data samples can be correlated to a specific date and time.
tep 5: After removing from the U B port, attach the X16-1D logger to the target object. The
logger is small and light weight so double-sided tape, Velcro, or a spot of cyanoacrylate
glue are sufficient methods of attachment.
tep 6: Press the on/off button located at the rear of the enclosure to initiate data recording, (see
Figure 9). Logging will start about 3-5 seconds after pressing the button. The red LED
will blink as the configuration file is accessed. If the time.txt file is present, the RTC is
initialized with the time written in the file. Then, the blue LED will begin to blink at a 1
second interval indicating the system is operating. The red LED will blink periodically
as data is written to the micro D card.
Gulf Coast Data Concepts Page 6 X16-1D, Rev B
Figure 8: Editing Config.txt File
The X16-1D is small and light weight so attachment methods do not need to be
substantial. Double-sided tape, a spot of cyanoacrylate glue (contact cement), ip-ties,
magnetic base, or adhesive putty are example methods of attachment. These methods do
not cause adverse signal attenuation considering the relatively low frequency bandwidth
of the X16-1D logger. Command Poster Adhesive strips by 3M offer excellent temporary
attachment of the logger to most surfaces.

tep 7: To stop recording, press and hold the button for about 3 seconds. The red and blue
LEDs will begin to blink rapidly for 2 seconds and then turn off. Release the button and
the X16-1D turns off. Pressing the button again restarts the logger and data is recorded
to a new file.
tep 8: Plug the logger into a PC and allow the logger to mount as a U B drive. The data file
will appear in the “GCDC” directory.
tep 9: The data recorded to the files must be converted to determine acceleration in “g” units.
Divide the Ax, Ay, Az columns by 2048 to determine g units. ee section 3.3 for a
complete discussion of data conversion.
Gulf Coast Data Concepts Page 7 X16-1D, Rev B
Figure 9: Starting the X16-1D
Figure 1 : Sensor Orientation
+Z
+Y
+X

2 Operation
2.1 USB Interface
The X16-1D connects to a PC using a standard Type-A U B connector and supports the U B mass
storage device interface for file access and file transfers. Nearly all computer operating systems
recognize the X16-1D as a typical U B external memory drive. When connected to a PC, the X16-1D
deactivates logging and operates only as a U B interface to the micro D card. Note that some tablet
operating systems block access to U B mass storage devices and will not recognize the X16-1D.
2.2 Memory Card
The X16-1D stores data to a removable 8GB micro D flash memory card and is compatible with
micro D and micro DHC type cards. The logger needs only the config.txt file to operate. The X16-
1D will use default configuration settings if the config.txt is not present. The “config.txt” and
“time.txt” files must occur in the root directory (see section 2.6 and section 2.4). The X16-1D will
create a folder called “GCDC”, if not already present, to place the data files.
2.3 Battery
The X16-1D is powered by a single “AA” sized battery. Gulf Coast Data Concepts recommends an
alkaline battery (AN I type 15A or IEC type LR6) or lithium battery (AN I type 15L or IEC FR6) to
operate the X16-1D. The battery is not used when the device is connected to a computer U B port.
The X16-1D will log constantly for approximately 48 hours at 50 Hz and approximately 28 hours at
100 Hz when using a standard alkaline AA battery. Figure 11 illustrates the expected continuous
logging time versus sample rate.
The RTC continues to operate from the battery when the device is “off”. The RTC should be
reinitialized if the battery is removed or completely depleted (see ection 2.4).
Gulf Coast Data Concepts Page 8 X16-1D, Rev B
Interrupting the power to the logger can result in corruption of the microSD card. For
example, removing the logger from the USB port during file transfers to the PC or
removing the battery during logging activity. Reformat the card if it becomes corrupted
(FAT32 file structure). If data transfers to/from the card become slow, consider formatting
the card using “SD Card Formatter” software provided by the SD Association
(www.sdcard.org).
Use a lithium primary AA battery to improve low temperature performance and extend
operating time. The lithium chemistry has a wider operating temperature -40°F – 140°F
(-40°C – 60°C) and about 30% more capacity over a standard alkaline battery.

2.4 Setting The RTC
A real time clock (RTC) integrated into the X16-1D determines the time for each line of data recorded.
The RTC is initialized using a user-created text file named “time.txt” located in the root directory of the
micro D card. This is a separate file from the config.txt file and it is needed only when initializing the
RTC. The system looks for the time.txt file upon booting. If the file exists, the time stored in the file is
loaded to the RTC and the time.txt file is deleted. The time information in the time.txt file must be in
Gulf Coast Data Concepts Page 9 X16-1D, Rev B
A 5v supply via the USB connector provides extended operation of the device independent
of the internal battery. Common USB power adapters or USB battery packs for consumer
electronics can provide the required 5v supply. The logger does not implement power
saving features when connected to an external power supply so power consumption will
be higher than when using the AA battery.
The logger is always “on” maintaining the real time clock and will eventually discharge the
battery completely after several months. The discharged battery may leak chemicals and
corrode the electronics. Remove the AA battery prior to long term storage of the X16-1D.
Figure 11: Expected Battery Life
The X16-1D is not compatible with NiMH type rechargeable batteries. The NiMH battery
delivers 1.2 volts nominally, which is near the voltage cut-off limit of the logger. The X16-
1D will not operate very long or may activate at all.

the exact “yyyy-MM-dd HH:mm:ss” 24-hour format, occur on the first line, and end with a newline
character. Figure 12 provides an example time.txt file that will initialize the RTC to 2:26:30 pm June
16, 2014.
The time file method of setting the RTC does not require special communication drivers so it can be
implemented using a simple text editor. Direct initialization of the RTC is possible but requires
specific device drivers and software from Gulf Coast Data Concepts.
The RTC maintains ±50ppm accuracy (-40°C to +85°C), which means that the accuracy may drift
about 4 seconds every day. The RTC is powered by the battery at all times, even when the logger is
“off”.
Gulf Coast Data Concepts Page 10 X16-1D, Rev B
Initiali ing the RTC ensures that the start time and individual time stamps can be
correlated to an absolute time – the year, month, day, hour, minute, second, and fractional
second. An uninitiali ed RTC or reset of the RTC will lead to indeterminate start time
recorded in the data file header.
After unplugging the logger from the USB port, the logger will load the config.txt file and
time.txt file, if present. Therefore, there is a delay between when the time.txt was created
and when the logger actually loads the time information. For most applications, this simple
method of initiali ing the clock results in sufficient accuracy.
Figure 12: Example Time Entry in time.txt File
Initiali ation of the RTC is limited to +/-1 second. The RTC register that handles the
fractional seconds counter is not accessible so the initiali ation process can not reset the
seconds to an even value.

2.5 Status Indicators
ystem status is indicated by the two LEDs located near the U B connector. The blue LED indicates
system operation and blinks once per second to indicate a properly operating system. The blue LED
blinks when the X16-1D is recording data, in standby mode, or is connected to a computer via the U B
port. The red LED blinks when data is written or read from the micro D memory card. In data
logging mode, the period at which the red LED blinks depends on the sample rate and other
configuration settings. The LEDs will flicker during user initiated shutdown. The “statusindicators”
tag in the configuration file turns off or changes the brightness of the status indicators (see section
3.2.4.10).
2.6 System Configuration Options
The X16-1D is configured using a set of tags and settings stored in a text file named “config.txt”,
which is located in the root directory of the micro D card. The system reads the configuration file at
boot time. Table 1 lists the configuration file tags. A tag is followed by an equal sign (“=”) and an
applicable tag setting. A line finishes with a newline character. Tags are not case sensitive. Tab and
space characters are ignored. Lines starting with a semicolon (“;”) are treated as comments and
ignored by the system. The system will use the default settings listed in Table 1 if the config.txt file is
not found.
Gulf Coast Data Concepts Page 11 X16-1D, Rev B
Figure 13: LED Status Indicators
Do not use the Windows Notepad editor because it does not terminate new lines properly.
GCDC recommends Windows Wordpad or Notepad++ to edit the config.txt file.

Table 1: Configuration File Tags and Descriptions
Tag Valid Settings Default Desc iption
deadband An integer between
0 and 16384
0 ets the deadband to a range expressed in “counts”.
A new sample is recorded if any sensor axis
exceeds the previous recorded reading by the
deadband value
deadbandtimeout An integer between
0 and 65535
3 pecifies the period in seconds when a sample is
recorded regardless of the deadband setting. This
feature ensures periodic data is recorded during
very long periods of inactivity.
dwell An integer between
0 and 65535
1 The number of samples recorded after a deadband
threshold triggered event
microres - Off The presence of this tag sets the device to record
time stamps with 0.1ms effective precision.
rebootondisconnect - off on disconnect The presence of this tag causes the system to start
recording after disconnect from a U B port.
samplesperfile An integer greater
than 0
90000 The number of lines of data per data file before a
new file is created
samplerate 12, 25, 50, 100,
200, 400
100 ets the rate at which data is collected and recorded
to the micro D card.
starttime and stoptime ee section 2.6.8 - Defines when to start and stop recording
stoponvusb - Off tops data logging if 5v U B power is present (see
section 2.6.9)
statusindicators “Normal”, “High”,
“Off”
Normal LED status indicators can be activated with normal
brightness (Normal), activated with high brightness
(High), or completely deactivated (Off).
2.6.1 deadband
“deadband” defines the minimum difference between recorded sensor readings. A new sample from
the accelerometer sensor must exceed the previous recorded reading before the logger records the data.
The deadband setting is expressed in "counts" units and is applied to the output of each axis. The
deadband value can be set to an integer between 0 and 32767. The deadband function is an effective
way to reduce the amount of data collected by defining the granularity of the data.
The deadband functions as a event threshold limit when used in conjunction with the “dwell” feature.
Figure 14 illustrates the deadband feature filtering out small changes in acceleration from the recorded
data. Only when the deadband limit is exceeded will a new data sample be pushed to the file. Note
that this feature will result in samples with inconsistent time periods. Therefore, the data sets should be
re-sampled to establish uniform time periods.
Gulf Coast Data Concepts Page 12 X16-1D, Rev B

2.6.2 deadbandtimeout
“deadbandtimeout” defines the period in seconds when a sample is recorded by the logger regardless of
the deadband setting. This feature ensures periodic data is recorded during extended periods of
inactivity. A valid setting for the deadbandtimeout is an integer between 0 and 16384.
2.6.3 dwell
Use “dwell” together with “deadband” to create an event trigger configuraion. The “dwell” tag defines
the number of consecutive samples recorded at the set sample rate after a deadband threshold event.
The deadband threshold event occurs when a sensor reading exceeds the last recorded value by the
deadband setting. A valid dwell setting is an integer between 0 and 65535. ee section 2.7.2 for an
example implementation of the deadband/dwell features.
Gulf Coast Data Concepts Page 13 X16-1D, Rev B
Figure 14: Graphical Illustration of the Deadband Feature
Figure 15: Graphical Illustration of the Dwell Feature

2.6.4 microres
The “microres” option sets the device to record time stamps with 0.1ms precision. In micro-resolution
mode, the time stamps are recorded as XX.YYYYZZ where XX are seconds, YYYY are 0.1
milliseconds, and ZZ are spurious digits beyond the precision capability. The micro-resolution option
should be implemented at sample rates greater than 200 hertz to provide the best timing precision.
2.6.5 rebootondisconnect
The X16-1D incorporates an on/off button for initiating and terminating the data recording process.
Data recording is automatically started upon disconnect from a computer U B port if the tag word
“rebootondisconnect” is included in the configuration file.
2.6.6 samplesperfile
“samplesperfile” defines the number of data lines each file can have before a new file is created. This
tag controls the size of the data files into easily manageable lengths for later processing. This setting is
loaded as a signed 32-bit integer, which can translate into very large data files. The user should
exercise caution before setting large files and test the end-user software application for data limitations.
2.6.7 samplerate
The “samplerate” tag defines the data rate in Hertz, or samples per second. Valid sample rate settings
are 12, 25, 50, 100, 200, and 400 Hz. ee section 4.1 for special features regarding the sample rates.
2.6.8 starttime and stoptime
The X16-1D starts and stops data recording based on the times defined using the “starttime” and
“stoptime” tags. The times must be in “MM HH DD” 24-hr format with the three entries separated by
a space. Entries marked with “*” operate as a wild card. The X16-1D continues to record after the
start time unless defined otherwise by the stoptime tag. Note that the configuration option does not
include the month. Example timing configurations:
Example 1: On the 15th day, start recording at 12:30pm and
stop recording at 6:00pm.
starttime = 30 12 15
stoptime = 00 18 15
Example 2: tart recording at the beginning of every hour
and stop recording 45 minutes later.
starttime = 00 *
stoptime = 45 *
Gulf Coast Data Concepts Page 14 X16-1D, Rev B
Micro-resolution is best suited for applications requiring precise timing, such as vibration
analysis, and is recommended for sample rates above 200 H . The standard timing
precision (default) of 1 milli-second is suitable for most general applications, such as
monitoring human motion.

2.6.9 stoponvusb
The “stoponvusb” tag stops data logging operations when a 5v supply is detected on the U B
connector. Without the stoponvusb option (default), the device switches power from the internal
battery to the U B 5v and continues to log data.
2.6.1 statusindicators
The brightness intensity of the LED status indicators is defined using the “statusindicators” tag and
valid settings of “normal”, “high”, and “off”.
2.7 Example Configuration Files
2.7.1 Example A
The following configuration records data at 100 hertz. Deadband and deadbandtimeout are set to zero
so the logger will record constantly at the set sample rate. Each data file is 90,000 lines long, which is
15 minutes of data. The status indicators are set to high brightness. The logger is activated with the
on/off button (notice “rebootondisconnect” is not active).
2.7.2 Example B
The deadband and dwell settings configure the device to record at least 5 seconds of data when a
change greater than 0.1g is detected. The deadbandtimeout setting forces a sample write every hour.
Gulf Coast Data Concepts Page 15 X16-1D, Rev B
Figure 16: Configuration File Example A
;Example X16-1D config file
;set sample rate
;available rates 12, 25, 50, 100, 200, 400
samplerate = 100
;recor constantly
ea ban = 0
ea ban timeout = 0
;set file size to 15 minutes of ata
samplesperfile = 90000
;set status in icator brightness
statusin icators = high
;rebootOnDisconnect
;see X16-1D user manual for other config options
Figure 17: Configuration File Example B
; Example X16-1D Config file
; set to 25Hz
samplerate = 25
; trigger at 0.1g
ea ban = 100
; recor 5 secon s of ata
well = 125
;force a write every hour
ea ban timeout = 3600
; set file length
samplesperfile = 30000
; LEDs on
statusin icators = normal

2.7.3 Example C
The logger must be turned on with the on/off button. It will enter a standby mode (blue LED blinks)
while it waits for the start time. The logger will start recording at 10:30am and turn off at 2:00pm. The
logger will record constantly at 400Hz and create 51 data files in the 3.5 hours. The micro-resolution is
activated to provide the best timing precision at the 400 Hz sample rate.
3 Data Interpretation
3.1 Data Files
The X16-1D creates a new data file when the system is booted or when the maximum number of data
lines is reached in the previous data file. A system boot condition occurs when the on/off button is
pressed, 5v power is restored to the system via the U B connector, or when the X16-1D is removed
from a computer U B port with the “rebootondisconnect” feature enabled. Data files are placed in a
folder named “GCDC” and are named data-XXX.csv, where XXX is a sequential number starting with
001. The system will create up to 999 files. At the beginning of each file, a header is written
describing the system configuration and the current time when the file was created. Figure 19
represents an example data file.
Gulf Coast Data Concepts Page 16 X16-1D, Rev B
A short gap in data may occur between sequential files as data is purged from the cache
and a new file is allocated on the microSD card.
Figure 18: Configuration File Example C
; Example X16-1D Config file
; set to 400Hz
samplerate = 400
; activate precision timing
microres
; recor constantly
ea ban = 0
ea ban timeout = 0
; set file length
samplesperfile = 100000
; set logger to turn on with clock
starttime = 30 10
stoptime = 00 14
; LEDs on
statusin icators = normal

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 Desc iption
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
ampleRate Rate at which data is recorded to the micro D card
tart_Time The current time when the data file was created
Temperature Not supported on X16-1D, reports -999
Title The name of the U B 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.gc ataconcepts.com, x16-1 , ADXL345
;Version, 1110, Buil ate, Dec 30 2015, SN:CCDC4016131F31B
;Start_time, 2016-01-04, 10:25:14.000
;Temperature, -999.00, eg C, Vbat, 1444, mv
;SampleRate, 100,Hz
;Dea ban , 0, counts
;Dea ban Timeout, 0,sec
;Hea ers, 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