Gulf Coast Data Concepts X16-4 User manual

X16-4
USB Accelerometer
Data Logger
User Manual
Document Revision: Rev B
Firmware ersion: 1110
Date: August 16, 2017

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 X16-4......................................................................................................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..............................................................................................................................................7
2.1 U B Interface...........................................................................................................................7
2.2 Memory Card...........................................................................................................................7
2.3 Battery......................................................................................................................................8
2.4 etting The RTC.......................................................................................................................9
2.5 tatus Indicators.....................................................................................................................10
2.6 ystem Configuration Options...............................................................................................11
2.6.1 deadband..........................................................................................................................12
2.6.2 deadbandtimeout..............................................................................................................12
2.6.3 dwell.................................................................................................................................12
2.6.4 microres............................................................................................................................13
2.6.5 rebootondisconnect..........................................................................................................13
2.6.6 samplesperfile..................................................................................................................13
2.6.7 samplerate........................................................................................................................14
2.6.8 starttime and stoptime......................................................................................................14
2.6.9 stoponvusb.......................................................................................................................14
2.6.10 statusindicators.................................................................................................................14
2.7 Example Configuration Files.................................................................................................14
2.7.1 Example A........................................................................................................................14
2.7.2 Example B........................................................................................................................15
2.7.3 Example C........................................................................................................................15
3 Data Interpretation.............................................................................................................................16
3.1 Data Files...............................................................................................................................16
3.2 Data Format...........................................................................................................................16
3.3 Data Conversion.....................................................................................................................17
3.3.1 Time tamps....................................................................................................................17
3.3.2 Acceleration.....................................................................................................................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
A

6 Appendix............................................................................................................................................23
6.1 What is an Accelerometer......................................................................................................23
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: X16-4 Data Logger.....................................................................................................................2
Figure 2: X16-4 and Accessories...............................................................................................................3
Figure 3: 5 Unit kit of Loggers..................................................................................................................3
Figure 4: X16-4 Data Logger Components...............................................................................................4
Figure 5: Exploded View of the X16-4.....................................................................................................4
Figure 6: Connecting to PC........................................................................................................................5
Figure 7: Editing the Config.txt File..........................................................................................................5
Figure 8: tarting the X16-4......................................................................................................................6
Figure 9: ensor Orientation......................................................................................................................7
Figure 10: Battery Pack Connectors..........................................................................................................8
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....................................................................12
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..............................................................................................15
Figure 19: Example Data File.................................................................................................................16
Figure 20: Time tamp Conversion Method...........................................................................................17
Figure 21: 800Hz ample Configuration................................................................................................20
Figure 22: Enclosure Dimensions...........................................................................................................20
Figure 23: pring-mass Accelerometer...................................................................................................23
Figure 24: implified MEM Accelerometer Design (L) and Actual MEM Accelerometer (R).........24
Figure 25: R Command Line Interface ..................................................................................................25
Figure 26: R tudio Interface ..................................................................................................................26
Index of Tables
Table 1: Configuration File Tags and Descriptions..................................................................................11
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 X16-4 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 X16-4. 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 X16-4
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 X16-4 and how to use the data.
Gulf Coast Data Concepts Page 1 X16-4, Rev B

1.4 Product Summary
The X16-4 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 X16-4 appears as a
standard mass storage device containing the comma delimited data files and the user setup file. The
X16-4 includes an internal 500mAh lithium-polymer rechargeable battery, which will recharge using
U B power.
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)
•Operates from internal lithium-polymer rechargeable battery
•Weight 1.3oz (48g)
•ize 1x1x4.1 inch (26x26x104 mm)
Gulf Coast Data Concepts Page 2 X16-4, Rev B
Figure 1: X16-4 Data Logger

1.6 Items Included with X16-4
1.6.1 Single Unit Purchase
The X16-4 is packaged with the logger, a USB extender cable, and a screwdriver.
1.6.2 5 Unit Kit
kit includes 5 X16-4 loggers, a USB extender cable, and a screwdriver.
Gulf Coast Data Concepts Page 3 X16-4, Rev B
Figure 2: X16-4 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 Red LED charge indicator L Enclosure hinge
E 500mAh Battery Pack M #6-32 3/4” screw
F Battery Connectors N #6 nut
G On/Off button O ADXL345 sensor
H Micro D card (under wrap)
Gulf Coast Data Concepts Page 4 X16-4, Rev B
Figure 4: X16-4 Data Logger Components
A
I
B
C
E
H
K
G
J
M
N
L
Figure 5: Exploded iew of the X16-4
0.75" Length
#6-32 Machine Screw
PCB Enclos re
(Top)
PCB Enclos re
(Cap)
PCB Enclos re
(Bottom)
On/Off B tton
#6-32 Hex N t
O
F
D

1.8 Quick Start Guide
The X16-4 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 X16-4.
Configuration settings and mounting methods will depend on the particular application.
tep 1: Plug the X16-4 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. A red LED located on the bottom side will
indicate the battery is charging. The LED will turn off when the battery is fully charged,
which takes about 2 hours.
tep 2: Configure the X16-4 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.
Gulf Coast Data Concepts Page 5 X16-4, Rev B
Figure 6: Connecting to PC
Figure 7: Editing the Config.txt File

tep 3: 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 4: After removing from the U B port, attach the X16-4 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 5: Press the on/off button located at the rear of the enclosure to initiate data recording, (see
Figure 8). 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.
tep 6: 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 X16-4 turns off. Pressing the button again restarts the logger and data is recorded to
a new file.
tep 7: 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 8: 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 6 X16-4, Rev B
Figure 8: Starting the X16-4
The X16-4 is small and light weight so attachment methods do not need to be substantial.
Double-sided tape, a spot of cyanoacrylate glue (contact cement , zip-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 X16-4
logger. Command Poster Adhesive strips by 3M offer excellent temporary attachment of
the logger to most surfaces.

2 Operation
2.1 USB Interface
The X16-4 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 X16-4 as a typical U B external memory drive. Therefore, the X16-4 will allow file
transfers to the micro D card like a common U B flash drive. When connected to a PC, the X16-4
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 X16-4.
2.2 Memory Card
The X16-4 stores data to a removable micro D flash memory card located beneath the white plastic
wrap. The included 8GB card is sufficient for most applications so the card does not need to be
removed or upgraded. However, the plastic wrap can be cut away to allow access to the card. The
logger uses FAT32 and is compatible with micro D and mico DHC type cards.
The logger needs only the config.txt file to operate. The X16-4 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 X16-4 will create a folder called “GCDC”, if not already present,
to place the data files.
Gulf Coast Data Concepts Page 7 X16-4, 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 .
Figure 9: Sensor Orientation
The white plastic wrap is used to aid the assembly process at GCDC but it can be
removed to allow access to the microSD card. The logger is USB 2.0 compliant but is
limited to about 700 KB/sec. Removing the microSD card and using a standard USB card
reader will permit faster transfer of data files.
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