Gulf Coast Data Concepts X16-1E User manual

X16-1E
USB Accelerometer
Data Logger
User Manual

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 X16-1E....................................................................................................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.....................................................................................................................10
2.5 tatus Indicators.....................................................................................................................11
2.6 ystem Configuration Options...............................................................................................11
2.6.1 absoluteTime....................................................................................................................12
2.6.2 deadBand..........................................................................................................................12
2.6.3 deadBandTimeOut...........................................................................................................13
2.6.4 dirName............................................................................................................................13
2.6.5 dwell.................................................................................................................................13
2.6.6 fileName...........................................................................................................................14
2.6.7 minBattVoltage................................................................................................................14
2.6.8 rebootOnDisconnect........................................................................................................14
2.6.9 samplesPerFile.................................................................................................................14
2.6.10 sampleRate.......................................................................................................................15
2.6.11 statusIndicators................................................................................................................15
2.6.12 wakeUpTime....................................................................................................................15
2.7 Example Configuration Files.................................................................................................15
2.7.1 Example A........................................................................................................................15
2.7.2 Example B........................................................................................................................16
2.7.3 Example C........................................................................................................................16
3 Data Interpretation.............................................................................................................................17
3.1 Data Files...............................................................................................................................17
3.2 Data Format...........................................................................................................................17
3.3 Data Conversion.....................................................................................................................18
3.3.1 Time tamps: Relative Mode...........................................................................................18
3.3.2 Time tamps: Absolute Mode..........................................................................................18
3.3.3 Acceleration.....................................................................................................................19
4 ystem Details...................................................................................................................................19
4.1 ensor.....................................................................................................................................19
4.1.1 ensor pecial Features...................................................................................................20
A

4.2 Operating and torage Conditions.........................................................................................21
4.3 Dimensions............................................................................................................................21
5 Troubleshooting.................................................................................................................................22
6 Appendix............................................................................................................................................24
6.1 What is an Accelerometer......................................................................................................24
6.2 Using “R” to Analyze Data....................................................................................................26
6.2.1 What is “R”......................................................................................................................26
6.2.2 Introduction to R Commands...........................................................................................27
6.2.3 Online Resources for R....................................................................................................28
6.2.4 Example cripts in R.......................................................................................................29
Inde of Figures
Figure 1: X16-1E Data Logger..................................................................................................................2
Figure 2: X16-1E and Accessories.............................................................................................................3
Figure 3: 5 Unit Kit of Loggers.................................................................................................................3
Figure 4: X16-1E Data Logger Components.............................................................................................4
Figure 5: Exploded View of the X16-1E...................................................................................................4
Figure 6: Installing Battery........................................................................................................................5
Figure 7: Connecting to PC........................................................................................................................5
Figure 8: Editing Config.txt File................................................................................................................6
Figure 9: tarting the X16-1E....................................................................................................................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............................................................................14
Figure 16: Configuration File Example A...............................................................................................16
Figure 17: Configuration File Example B...............................................................................................16
Figure 18: Configuration File Example C...............................................................................................16
Figure 19: Example Data File..................................................................................................................17
Figure 20: Time tamp Conversion Method............................................................................................18
Figure 21: 800Hz ample Configuration.................................................................................................21
Figure 22: X16-1E Mechanical Dimensions............................................................................................21
Figure 23: pring-mass Accelerometer....................................................................................................24
Figure 24: implified MEM Accelerometer Design (L) and Actual MEM Accelerometer (R)..........25
Figure 25: R Command Line Interface....................................................................................................26
Figure 26: R tudio Interface....................................................................................................................27
Inde of Tables
Table 1: Configuration File Tags and Descriptions..................................................................................12
Table 2: Example Data Conversion.........................................................................................................19
Table 3: Accelerometer ensor Characteristics........................................................................................20
Table 4: Operating and torage Conditions.............................................................................................21
B

1 Introduction
1.1 About This Manual
Thank you for purchasing the X16-1E 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 X16-1E. If the
logger fails to operate as expected, please refer to the troubleshooting guide (page 22).
1.2 Document Conventions
The quick start guide in section 1.8 provides a basic summary of operation to begin using the X16-1E
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 Appendi
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 X16-1E and how to use the data.
Gulf Coast Data Concepts Page 1 X16-1E, Rev New

1.4 Product Summary
The X16-1E 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 X16-1E appears as a
standard mass storage device containing the comma delimited data files and the user setup file. The
X16-1E 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 X16-1E, Rev New
Figure 1: X16-1E Data Logger

1.6 Items Included with X16-1E
1.6.1 Single Unit Purchase
The X16-1E 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 X16-1E loggers, a USB extender cable, and a screwdriver. Batteries are not
included with kits.
Gulf Coast Data Concepts Page 3 X16-1E, Rev New
Figure 2: X16-1E 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 X16-1E, Rev New
Figure 4: X16-1E Data Logger Components
A
I
B
C
D
H
E
K
G
F
J
M
N
O
L
Figure 5: E ploded View of the X16-1E
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 X16-1E 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 X16-1E.
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 X16-1E 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 logger's serial number.
Gulf Coast Data Concepts Page 5 X16-1E, Rev New
Figure 6: Installing Battery
Figure 7: Connecting to PC

tep 3: Configure the X16-1E 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
so that the data samples can be correlated to a specific date and time.
tep 5: After removing from the U B port, attach the X16-1E logger to the target object. The
logger is small and lightweight, 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. 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 X16-1E, Rev New
Figure 8: Editing Config.t t File
The X16-1E is small and lightweight, so attachment methods do not need to be
substantial. Double-sided tape, a spot of cyanoacrylate glue (contact cement , zip-ties, a
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 X16-1E 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 X16-1E 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 files
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, and 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 X16-1E, Rev New
Figure 9: Starting the X16-1E
Figure 10: Sensor Orientation
+Z
+Y
+X
The data files contain raw digital data from the sensor. To determine acceleration in g's,
divide the raw data by 2048. A “g” is 32.174 ft/sec2 or 9.807 m/sec2.

2 Operation
2.1 USB Interface
The X16-1E 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 X16-1E as a typical U B external memory drive. When connected to a PC, the X16-1E
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 X16-1E.
2.2 Memory Card
The X16-1E stores data to a removable 8GB micro D flash memory card and is compatible with
micro D and micro DHC type cards. The logger uses FAT32 file structure, so cards larger than 8GB
are supported.
The logger needs only the config.txt file to operate. The X16-1E 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 X16-1E will create a folder called “GCDC”, if not already
present, to place the data files.
2.3 Battery
The X16-1E 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 X16-1E. The battery is not used when the device is connected to a computer U B port.
The X16-1E will log constantly for approximately 50 hours at 50 Hz and approximately 29 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 X16-1E, Rev New
Interrupting the power to the logger, for example, removing the logger from the USB port
during file transfers to the PC or removing the battery during logging activity, can result in
corruption of the microSD card. 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 .
Note that the logger does not record data while connected to a PC.

Gulf Coast Data Concepts Page 9 X16-1E, Rev New
Use a lithium primary AA battery to improve low temperature performance and extend
operating time. The lithium chemistry has a wider operating temperature of -40°F – 140°F
(-40°C – 60°C and about 30% more capacity over a standard alkaline battery.
The X16-1E 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-
1E will not operate very long or may not activate at all.
The logger is always “on” as it maintains 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-
1E.
The X16-1E will not operate from an external 5v USB power supply, unlike previous
versions of this logger. Extending the operating time is only achieved with larger battery
capacity added directly to the AA battery terminals.
Figure 11: E pected Battery Life

2.4 Setting The RTC
A real time clock (RTC) integrated into the X16-1E determines the time for each line of data recorded.
The RTC is initialized using a user-created text file named “time.txt” that is loaded by the logger upon
booting. 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.
Initializing the RTC with a time.txt file is accomplished as follows:
tep 1: Use Wordpad, or an equivalent text editor, to create a simple text file called
“time.txt”.
tep 2: Enter on the first line the current date and time as “yyyy-MM-dd HH:mm:ss” in
24-hr format. Figure 12 provides an example time.txt file that will initialize the
RTC to 2:26:30 pm June 16, 2014.
tep 3: ave this file to the root directory of the micro D card (same location as the
config.txt file) and close the text editor.
tep 4: Remove the logger form the PC. The logger will automatically find the time.txt
file and intialize the RTC with the time stored in the file. The file is deleted after
initialization.
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 X16-1E, Rev New
Initializing 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 uninitialized RTC or reset of the RTC will lead to indeterminate start time
recorded in the data file header.
Figure 12: E ample Time Entry in time.t t File

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 X16-1E is recording data, in standby mode, or 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
2.6.11).
2.6 System Configuration Options
The X16-1E 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. Tags that require a setting must be followed by an equal
sign (“=”) and an applicable tag setting. A line finishes with a newline character. Tags are not case
Gulf Coast Data Concepts Page 11 X16-1E, Rev New
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 initializing the clock results in sufficient accuracy.
Figure 13: LED Status Indicators
Initialization of the RTC is limited to +/-1 second. The RTC register that handles the
fractional seconds counter is not accessible so the initialization process cannot reset the
seconds to an even value.

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.
Table 1: Configuration File Tags and Descriptions
Tag Valid Settings Default Desc iption
absoluteTime - Off Time stamps relative to epoch (Jan 1, 1970)
deadBand An integer between
0 and 16384
0 A new sample is recorded if any sensor axis
exceeds the previous recorded reading by the
deadband value
deadBandTimeOut An integer between
0 and 16384
3 pecifies the period in seconds when a sample is
recorded regardless of the deadband setting
dirName Character text /GCDC Defines directory name to store data files
dwell An integer between
0 and 65535
1 The number of samples recorded after a deadband
threshold triggered event
fileName Character text DATA- File name prefix for the data files
minBattVoltage An integer greater
than 0
1200 set the minimum operating battery voltage (mV)
rebootOnDisconnect - Off 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.
statusIndicators “Normal”, “High”,
“Off”
Normal LED status indicators can be activated with normal
brightness (Normal), activated with high brightness
(High), or completely deactivated (Off).
wakeUpTime integers Off Activates logger at specific times
2.6.1 absoluteTime
By default, the time stamps represent the elapsed seconds since the start_time value listed in the file
header. “absoluteTime” changes the start reference to midnight January 1, 1970, otherwise known as
“epoch” or Unix time 0.
2.6.2 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.
Gulf Coast Data Concepts Page 12 X16-1E, Rev New
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.

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 16384. 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.
2.6.3 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.
2.6.4 dirName
The logger will store data files into the directory defined by “dirName”. The directory must be defined
with a preceding slash, such as “dirName=/GCDC”. By default, the data directory is set to the root
location /GCDC.
2.6.5 dwell
Use “dwell” together with “deadBand” to create an event trigger configuration. 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 X16-1E, Rev New
Figure 14: Graphical Illustration of the Deadband Feature

2.6.6 fileName
“fileName” sets the prefix name of the data files. By default, fileName is set to “DATA-”.
2.6.7 minBattVoltage
The logger will initiate a low-battery shutdown when the minBattVoltage is detected. By default, the
minBattVoltage is set to 1200 millivolts.
2.6.8 rebootOnDisconnect
The X16-1E 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.
2.6.9 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.
Gulf Coast Data Concepts Page 14 X16-1E, Rev New
Figure 15: Graphical Illustration of the Dwell Feature
The default minimum battery voltage is set to 1200 millivolts to ensure that the alkaline
battery can provide the necessary current to support microSD write operations. Care must
be taken when modifying the minBattVoltage parameter.

2.6.10 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.
2.6.11 statusIndicators
The brightness intensity of the LED status indicators is defined using the “statusIndicators” tag and
valid settings of “normal”, “high”, and “off”.
2.6.12 wakeUpTime
The “wakeUpTime” option configures the logger to turn on at specific times each day. Parameters are
separated by spaces and are in order of minutes then hours. Multiple parameters are separated by
commas. For example, “wakeUpTime=5,20 4,15” turns the logger on at 5 minutes and 20 minutes past
the hour of 4am and 3pm. “wakeUpTime=*” will turn the logger on with each minute. There are three
additional parameters needed to complete the wakeUpTime option and each must be on a separate line
in the config.txt file:
“secsToRecord” defines the time period of data to record in seconds. For example,
“secsToRecord=50” will record 50 seconds of data after a wake up event.
“fileAppend” will append new data to the previous available data file. The logger
will create a new file with each wake up event if fileAppend is not used.
“offOnEndRecord” turns the logger off after the completion of each wake up event.
This option saves power since the logger is not active between wake up
events. Otherwise, the logger will stay in a standby mode (blue LED blinks)
while waiting for the next wake up event.
Each time the logger completes a wake up event, the remaining portion of the memory sector is filled
with a repeating comment string (“;sectalign”). This procedure ensures that the next wake up event
starts on a new memory sector, which makes flash memory allocation easier for the logger. For the
end-user, ignore these “;sectalign” comment strings.
2.7 E ample Configuration Files
2.7.1 E ample 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).
Gulf Coast Data Concepts Page 15 X16-1E, Rev New
A wakeUpTime event is triggered upon the first time the logger is turned on, regardless of
the clock time. After this event completes, the logger will record data at the times specified
by the wakeUpTime option.

2.7.2 E ample 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.
2.7.3 E ample 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 wake up time. The logger will start recording at 4:30pm and record 5 minutes of
data every day.
Gulf Coast Data Concepts Page 16 X16-1E, Rev New
Figure 17: Configuration File E ample B
Figure 16: Configuration File E ample A
;Example X16-1E config file
;set sample rate
samplerate = 100
;record constantly
deadband = 0
deadbandtimeout = 0
;set file size to 15 minutes of data
samplesperfile = 90000
;set status indicator brig tness
statusindicators = ig
;rebootOnDisconnect
Figure 18: Configuration File E ample C
; Example X16-1E Config file
; set to 400Hz
samplerate = 400
; record constantly
deadband = 0
deadbandtimeout = 0
; wake up at 4:30pm
wakeUpTime = 30 16
; record 5 min
secToRecord = 300
; set file lengt
samplesperfile = 100000
statusindicators = normal
; Example X16-1E Config file
; set to 25Hz
samplerate = 25
; trigger at 0.1g
deadband = 205
; record 5 seconds of data
dwell = 125
;force a write every our
deadbandtimeout = 3600
; set file lengt
samplesperfile = 30000
; LEDs on
statusindicators = normal

3 Data Interpretation
3.1 Data Files
The X16-1E 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 or when the X16-1E 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 directory and file prefix are configurable
parameters (see sections 2.6.4 and 2.6.6). 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.
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. 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 (default mode) or relative to Jan 1, 1970 (absoluteTime mode). Figure 19 represents an
example data file.
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 (“;”).
Figure 19: E ample Data File
Gulf Coast Data Concepts Page 17 X16-1E, Rev New
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.
;Title, ttp://www.gcdataconcepts.com, x16-1e, ADXL345
;Version, 2037, Build date, Dec 18 2020, SN:CCDC5016091F6D5
;Start_time, 2021-05-25, 10:25:14.000
;Uptime, 5,sec, Vbat, 1292, mv, EOL, 3500, mv
;SampleRate, 100,Hz
;Deadband, 0, counts
;DeadbandTimeout, 0.000,sec
;Time, Ax, Ay, Az
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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