NXP Semiconductors
User's Guide
Document Number: SLN-VIZNAS-IOT-UG
Rev.1.1, 10/2020
MCU VIZNAS Solution User’s Guide
TABLE OF CONTENTS
1
INTRODUCTION ............................................................................................................................................ 6
1.1
1.2
2
RT106F VISION CROSSOVER PROCESSOR OVERVIEW ......................................................................................6
ADDITIONAL PERIPHERALS......................................................................................................................................7
GET STARTED WITH SLN-VIZNAS-IOT ............................................................................................................ 9
2.1 BOX CONTENTS....................................................................................................................................................9
2.2 RUNNING THE DEMO ............................................................................................................................................9
2.2.1
Access the Camera ...............................................................................................................................10
2.2.2
Register a Face .....................................................................................................................................12
2.2.3
Liveness Detection and Anti-Spoofing ..................................................................................................14
2.2.4
Connect to Serial CLI ............................................................................................................................16
2.2.5
Enable Verbose Mode ..........................................................................................................................18
2.2.6
(Optional) Enable Low Power Mode ....................................................................................................20
3
ADDITIONAL FEATURES .............................................................................................................................. 22
3.1 PUSH BUTTONS..................................................................................................................................................22
3.1.1
SW1 – Toggle GUI ................................................................................................................................23
3.1.2
SW2 – Manual Deregistration..............................................................................................................24
3.1.3
SW3 – Toggle IR/RGB Output ..............................................................................................................26
3.1.4
SW4 – Manual Registration .................................................................................................................27
3.2 SERIAL COMMANDS ............................................................................................................................................29
3.2.1
List Available Commands .....................................................................................................................29
3.2.2
List All Registered Users .......................................................................................................................31
3.2.3
Manually Add Users .............................................................................................................................31
3.2.4
Manually Delete Users .........................................................................................................................32
3.2.5
Rename Users ......................................................................................................................................32
3.2.6
Verbose Mode ......................................................................................................................................32
3.2.7
Configure IR LED Brightness .................................................................................................................35
3.2.8
Configure White LED Brightness ..........................................................................................................35
3.2.9
Print Version Information ....................................................................................................................35
3.2.10
Save Users Through Resets .............................................................................................................36
3.2.11
Enable OTW (Over-the-Wire) Update Mode ...................................................................................36
3.2.12
Reset the SLN-VIZNAS-IOT ...............................................................................................................36
3.2.13
Configure Emotion Recognition ......................................................................................................37
3.2.14
Configure Liveness Detection ..........................................................................................................38
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3.2.15
Configure Detection Resolution.......................................................................................................39
3.2.16
Display IR Output ............................................................................................................................40
3.2.17
Configure Display Output Device (Requires Riverdi Display) ...........................................................41
3.2.18
Toggle GUI.......................................................................................................................................41
3.2.19
Toggle Wi-Fi Enablement ................................................................................................................42
3.2.20
Reset Wi-Fi ......................................................................................................................................43
3.2.21
Retrieve Wi-Fi Credentials ...............................................................................................................43
3.2.22
Configure Wi-Fi Credentials.............................................................................................................43
3.2.23
Retrieve IP Address ..........................................................................................................................44
3.2.24
Erase Wi-Fi Credentials ...................................................................................................................44
3.2.25
Configure Application Type .............................................................................................................44
3.2.26
Configure Low Power Mode ............................................................................................................45
3.3 REMOTE (WIRELESS) REGISTRATION ......................................................................................................................45
3.3.1
Select Wireless Configuration ..............................................................................................................45
3.3.2
Connect Kits .........................................................................................................................................46
3.3.3
Manage Users ......................................................................................................................................48
3.4 REMOTE CREDENTIAL PROVISIONING .....................................................................................................................51
3.5 APP CONFIGURATIONS ........................................................................................................................................52
3.5.1
Light vs. Heavy .....................................................................................................................................52
3.5.2
E-Lock vs. Door Access vs. UserID ........................................................................................................53
3.6 LOW POWER MODE ...........................................................................................................................................54
3.7 AUDIO FEEDBACK ...............................................................................................................................................55
3.8 DISPLAY CONFIGURATIONS ...................................................................................................................................56
4
TROUBLESHOOTING ................................................................................................................................... 58
4.1 REGISTERING A FACE ...........................................................................................................................................58
4.1.1
Turn off Liveness Detection ..................................................................................................................58
4.1.2
Change App Type .................................................................................................................................58
4.1.3
Debug Using Verbose Mode.................................................................................................................58
4.1.4
Ensure Lighting is Sufficient .................................................................................................................59
4.1.5
Adjust Face Proximity and Position ......................................................................................................60
5
DOCUMENT DETAILS................................................................................................................................... 62
5.1
5.2
5.3
REFERENCES ......................................................................................................................................................62
ACRONYMS, ABBREVIATIONS, & DEFINITIONS ..........................................................................................................62
REVISION HISTORY..............................................................................................................................................63
TABLE OF FIGURES
FIGURE 1: SLN-VIZNAS-IOT ADDITIONAL PERIPHERALS ...........................................................................................................7
FIGURE 2: DUAL CAMERA ADAPTER KIT CONFIGURATION...........................................................................................................7
FIGURE 3: SLN-VIZNAS-IOT BOX CONTENTS .........................................................................................................................9
FIGURE 4: PLUGGING IN SLN-VIZNAS-IOT KIT .......................................................................................................................9
FIGURE 5: WINDOWS CAMERA APP .....................................................................................................................................10
FIGURE 6: SLN-VIZNAS-IOT CAMERA OUTPUT IN CAMERA APP..............................................................................................11
FIGURE 7: CHANGE CAMERA BUTTON IN WINDOWS CAMERA APP.............................................................................................11
FIGURE 8: SLN-VIZNAS-IOT MANUAL REGISTRATION BUTTON ...............................................................................................12
FIGURE 9: REGISTRATION IN PROGRESS.................................................................................................................................12
FIGURE 10: SUCCESSFUL REGISTRATION ................................................................................................................................13
FIGURE 11: REGISTRATION FAILED .......................................................................................................................................13
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FIGURE 12: "WELCOME HOME" MESSAGE ...........................................................................................................................14
FIGURE 13: PHONE DISPLAY SPOOF ATTACK ..........................................................................................................................14
FIGURE 14: PRINTED PICTURE SPOOF ATTACK........................................................................................................................15
FIGURE 15: FAKE FACE DETECTED .......................................................................................................................................15
FIGURE 16: SERIAL CONNECTION SETTINGS ...........................................................................................................................16
FIGURE 17: SERIAL COMMANDS "HELP" MENU .....................................................................................................................17
FIGURE 18: "VERBOSE 0" ...................................................................................................................................................18
FIGURE 19: EXAMPLE VERBOSE MODE DEBUG MESSAGE.........................................................................................................18
FIGURE 20: ON-SCREEN INFO FOR REGISTERING FACE .............................................................................................................19
FIGURE 21: ON-SCREEN INFO FOR RECOGNIZED FACE..............................................................................................................20
FIGURE 22: "RECOGNITION TIMEOUT" MESSAGE ...................................................................................................................21
FIGURE 23: HIBERNATION WAKE-UP TRIGGER (SW3) .............................................................................................................21
FIGURE 24: SW1 .............................................................................................................................................................23
FIGURE 25: GUI TOGGLED OFF...........................................................................................................................................23
FIGURE 26: SW2 .............................................................................................................................................................24
FIGURE 27: DEREGISTRATION IN PROGRESS ...........................................................................................................................24
FIGURE 28: "USERNAME REMOVED" MESSAGE ..................................................................................................................25
FIGURE 29: "REMOVE FAILED" ...........................................................................................................................................25
FIGURE 30: SW3 .............................................................................................................................................................26
FIGURE 31: SW3 .............................................................................................................................................................26
FIGURE 32: SW4 .............................................................................................................................................................27
FIGURE 33: REGISTRATION IN PROGRESS...............................................................................................................................27
FIGURE 34: SUCCESSFUL REGISTRATION ................................................................................................................................28
FIGURE 35: REGISTRATION FAILED .......................................................................................................................................28
FIGURE 36: "WELCOME HOME" MESSAGE ...........................................................................................................................29
FIGURE 37: "LIST" COMMAND ............................................................................................................................................31
FIGURE 38: "ADD COOPER" COMMAND ...............................................................................................................................31
FIGURE 39: "ADD -S" COMMAND ........................................................................................................................................32
FIGURE 40: "DEL COOPER" COMMAND ................................................................................................................................32
FIGURE 41: "DEL -A" COMMAND.........................................................................................................................................32
FIGURE 42: "RENAME USER_0 COOPER" COMMAND ..............................................................................................................32
FIGURE 43: "VERBOSE 0" ...................................................................................................................................................32
FIGURE 44: EXAMPLE VERBOSE MODE DEBUG MESSAGE.........................................................................................................33
FIGURE 45: ON-SCREEN INFO FOR REGISTERING FACE .............................................................................................................34
FIGURE 46: ON-SCREEN INFO FOR RECOGNIZED FACE..............................................................................................................34
FIGURE 47: "IR_PWM 60" COMMAND .................................................................................................................................35
FIGURE 48: "CAMERA IR PWM NOT SUPPORTED" MESSAGE ...................................................................................................35
FIGURE 49: "IR_PWM 60" COMMAND .................................................................................................................................35
FIGURE 51: "VERSION" COMMAND ......................................................................................................................................35
FIGURE 52: "SAVE 3" COMMAND ........................................................................................................................................36
FIGURE 53: "SAVE" COMMAND ..........................................................................................................................................36
FIGURE 54: "RESET" COMMAND .........................................................................................................................................36
FIGURE 55: "EMOTION 4" COMMAND SUCCESS OUTPUT .........................................................................................................37
FIGURE 56: "EMOTION 4" ..................................................................................................................................................38
FIGURE 57: "LIVENESS OFF" COMMAND ................................................................................................................................38
FIGURE 58: "LIVENESS ON" COMMAND ................................................................................................................................38
FIGURE 59: VGA VS. QVGA DETECTION RESOLUTION MAX RANGE ..........................................................................................39
FIGURE 60: "DETECTION RESOLUTION VGA" COMMAND...........................................................................................................39
FIGURE 61: "DETECTION RESOLUTION QVGA" COMMAND ........................................................................................................40
FIGURE 62: "DISPLAY OUTPUT_MODE IR" COMMAND .............................................................................................................40
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FIGURE 63: IR DISPLAY OUTPUT .........................................................................................................................................40
FIGURE 64: "DISPLAY MODE NOT SUPPORTED" MESSAGE .........................................................................................................40
FIGURE 65: RIVERDI DISPLAY ..............................................................................................................................................41
FIGURE 66: "DISPLAY OUTPUT_DEVICE RIVERDI" COMMAND.....................................................................................................41
FIGURE 67: "DISPLAY INTERFACE LOOPBACK" COMMAND .........................................................................................................41
FIGURE 68: GUI TOGGLED OFF...........................................................................................................................................41
FIGURE 69: "WI-FI WILL START" MESSAGE ...........................................................................................................................42
FIGURE 70: "WI-FI DRIVER IS CONNECTING" MESSAGE ............................................................................................................42
FIGURE 71: "WI-FI DRIVER IS ON" MESSAGE .........................................................................................................................42
FIGURE 72: "WIFI ON" COMMAND ......................................................................................................................................42
FIGURE 73: "WI-FI WILL STOP" MESSAGE .............................................................................................................................42
FIGURE 74: "WI-FI DRIVER IS OFF" MESSAGE ........................................................................................................................42
FIGURE 75: "WIFI RESET" COMMAND ...................................................................................................................................43
FIGURE 76: "WIFI CREDENTIALS" COMMAND .........................................................................................................................43
FIGURE 77: "WI-FI CREDENTIALS NOT FOUND" MESSAGE ........................................................................................................43
FIGURE 78: "WIFI CREDENTIALS" W/ ARGS ............................................................................................................................43
FIGURE 79: "WIFI CREDENTIALS" W/ BAD ARG .......................................................................................................................43
FIGURE 80: "WIFI IP" COMMAND SUCCESSFUL .......................................................................................................................44
FIGURE 81: "WIFI IP" COMMAND UNSUCCESSFUL...................................................................................................................44
FIGURE 82: "WIFI ERASE" COMMAND ..................................................................................................................................44
FIGURE 83: "APP_TYPE" COMMAND ....................................................................................................................................45
FIGURE 84: "LOW_POWER ON" COMMAND ..........................................................................................................................45
FIGURE 85: FACEREC MANAGER HOME SCREEN ....................................................................................................................46
FIGURE 86: "SMART LOCKS" MANAGEMENT PAGE .................................................................................................................46
FIGURE 87: BLE CONNECTIONS IN RANGE.............................................................................................................................47
FIGURE 88: CONFIGURE SMARTLOCK INFORMATION ...............................................................................................................47
FIGURE 89: "MANAGE SMART LOCKS" TAB ...........................................................................................................................48
FIGURE 90: CONNECTED LOCKS...........................................................................................................................................48
FIGURE 92: REMOTE REGISTRATION SCREEN .........................................................................................................................49
FIGURE 91: REMOTE FACE CAPTURE SCREEN .........................................................................................................................49
FIGURE 93: "MANAGE USERS" TAB .....................................................................................................................................50
FIGURE 94: USER LIST SCREEN ............................................................................................................................................50
FIGURE 95: REMOTE DELETION SCREEN................................................................................................................................51
FIGURE 96: LOW POWER TIMEOUT FLOW .............................................................................................................................54
FIGURE 97: "RECOGNITION TIMEOUT" MESSAGE ...................................................................................................................55
FIGURE 98: J3 SPEAKER CONNECTOR ...................................................................................................................................56
FIGURE 99: RIVERDI RVT28UEFNWC10 ............................................................................................................................56
FIGURE 100: "REGISTRATION FAILED" + VERBOSE MODE OUTPUT ............................................................................................59
FIGURE 101: BAD RGB LIGHTING .......................................................................................................................................59
FIGURE 102: BAD IR LIGHTING ...........................................................................................................................................60
FIGURE 103: IMPROPER FACE ANGLE & PROXIMITY ................................................................................................................60
TABLE OF TABLES
TABLE 1: SUPPORTED COMPUTER CONFIGURATIONS .................................................................................................................8
TABLE 2: WI-FI FREQUENCY & POWER...................................................................................................................................8
TABLE 3: VERBOSE MODE CONFIGURATION TABLE..................................................................................................................18
TABLE 4: VERBOSE MODE ABBREVIATION TABLE ....................................................................................................................19
TABLE 5: PUSH BUTTONS FUNCTIONALITY .............................................................................................................................22
TABLE 6: SERIAL COMMAND TABLE ......................................................................................................................................31
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TABLE 7: VERBOSE MODE CONFIGURATION TABLE..................................................................................................................33
TABLE 8: VERBOSE MODE ABBREVIATION TABLE ....................................................................................................................33
TABLE 9: EMOTION RECOGNITION CONFIGURATION TABLE .......................................................................................................37
TABLE 10: VGA VS. QVGA................................................................................................................................................39
TABLE 11: APP TYPE ARGUMENTS .......................................................................................................................................44
TABLE 12: APP CONFIGURATIONS........................................................................................................................................52
TABLE 13: REFERENCE DOCUMENTS ....................................................................................................................................62
TABLE 14: ABBREVIATIONS AND DEFINITIONS ........................................................................................................................63
TABLE 15: REVISION HISTORY .............................................................................................................................................63
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1 Introduction
NXP’s MCU-based SLN-VIZNAS-IOT development kit provides OEMs with a fully
integrated, self-contained, software and hardware solution. This includes the i.MX
RT106F run-time library and pre-integrated machine learning face recognition algorithms,
as well as all required drivers for peripherals, such as camera and memories.
This cost-effective, easy-to-use face recognition implementation facilitates the demand
for a face-based “Friction Free Interface” that can be embedded in a variety of products
across home, commercial and industrial applications, thus eliminating the need to use
hard to learn and time-consuming mechanisms to identify users.
TARGET APPLICATIONS
•
•
•
•
•
Safety/Security/Alarm devices: E-locks, Alarm panels, remote sensors, and
automated access
Smart appliances: Washing machines, dryers, ovens, refrigerators, stoves, and
dishwashers
Home comfort devices: Thermostats, remote temperature sensors, and lighting
Counter-top appliances: Microwaves, coffee machines, rice cookers, and
blenders
Smart industrial devices: Power tools, ergonomic stations, machine access and
authorization
1.1 RT106F VISION CROSSOVER PROCESSOR OVERVIEW
The i.MX RT106F is an EdgeReady member of the i.MX RT1060 family of crossover
processors, targeting low cost embedded face recognition applications. It features NXPs
advanced implementation of the Arm® Cortex®-M7 core, which operates at speeds up to
600 MHz to provide high CPU performance and best real-time responses. This i.MX
RT106F-based solution enables system designers to easily and inexpensively add face
recognition capabilities to a wide variety of smart appliances, smart homes, and smart
industrial devices. The i.MX RT106F processor is licensed to run NXPs i.MX RT run-time
library for face recognition which may include:
•
•
•
•
•
•
•
•
•
6
Camera drivers
Image capture
Image pre-processing
Face alignment
Face tracking
Face detection
Face recognition
Liveness Detection
Emotion recognition
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1.2 Additional Peripherals
In addition to the i.MX RT106F, included in the kit are many additional peripherals
essential to experiencing everything the SLN-VIZNAS-IOT kit has to offer. Many of these
peripherals are shown in the figure below.
Figure 1: SLN-VIZNAS-IOT Additional Peripherals
Additionally, the SLN-VIZNAS-IOT kit comes with an IR+RGB Dual Camera Adapter like
that shown below for use in secure applications.
Figure 2: Dual Camera Adapter Kit Configuration
Depending on the mode of operation, devices using the Dual Camera Adapter can
emit highly concentrated non-visible infrared light which can be hazardous to the
human eye. Products which incorporate these devices must follow the safety
precautions given in IEC 60825-1 and IEC 62471.
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Recommended Computer Configuration
The MCU SLN-VIZNAS-IOT SDK requires an up-to-date computer which runs the
MCUXpresso IDE version 11.2. It also requires a terminal program to communicate with
the device via USB.
https://www.nxp.com/support/developer-resources/software-developmenttools/mcuxpresso-software-and-tools/mcuxpresso-integrated-developmentenvironment-ide:MCUXpresso-IDE
Computer type
Apple
PC
PC
OS version
Mac OS
Windows 7 / 10
Linux
Terminal
PuTTY
PuTTY/Tera Term
PuTTY
Table 1: Supported Computer Configurations
Usage Condition
The following information is provided per Article 10.8 of the Radio Equipment Directive
2014/53/EU:
(a) Frequency bands in which the equipment operates.
(b) The maximum RF power transmitted.
PN
RF Technology
(a) Freq Range
(b) Max Transmitted Power
SLN-VIZNAS-IOT
Wi-Fi
2412MHz-2472MHz
17.9dBm
Table 2: Wi-Fi Frequency & Power
EUROPEAN DECLARATION OF CONFORMITY (Simplified DoC per Article 10.9 of
the Radio Equipment Directive 2014/53/EU)
This apparatus, namely SLN-VIZNAS-IOT, conforms to the Radio Equipment Directive
2014/53/EU. The full EU Declaration of Conformity for this apparatus can be found at this
location: https://www.nxp.com/mcu-vision
To maintain EMC Compliance, the CLOCK_DRIVE_STRENGTH_LOW
preprocessor macro* must remain set to 1
**NOTE: See SLN-VIZNAS-IOT Developer’s Guide for information on changing preprocessor macros
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2 Get Started with SLN-VIZNAS-IOT
2.1 Box Contents
The SLN-VIZNAS-IOT kit arrives in a box alongside a printed Quick Start Guide and a
USB-C Cable.
Figure 3: SLN-VIZNAS-IOT Box Contents
Please check your kit for damage or marks, and, if seen, please contact your NXP
representative.
2.2 Running the Demo
To get started, take the USB-C cable provided inside the kit and plug the USB-A end into
your computer and the USB-C end into your kit.
Figure 4: Plugging in SLN-VIZNAS-IOT Kit
Once connected, a green LED (D1) will light up to indicate the kit is powered on.
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2.2.1 Access the Camera
NOTE: Camera enumeration is currently supported on Windows and Ubuntu.
With the kit powered on and connected to your computer, the SLN-VIZNAS-IOT kit will
automatically enumerate as both a serial device and USB camera device. To access the
kit’s camera, open Camera if using Windows, or Cheese, if using Ubuntu. In this guide,
we’ll be using Windows and the Windows camera app.
Figure 5: Windows Camera App
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After opening the camera app, video coming directly from the kit will be shown in the app’s
camera window:
Figure 6: SLN-VIZNAS-IOT Camera Output in Camera App
NOTE: The Windows Camera app has a “face finder” feature of its own, shown by the smaller blue
box around the face in the above screenshot.
If you have multiple cameras connected to your computer, you may need to change which
camera is being shown. In the Windows Camera app, this can be done by using the
“Change Camera” button located in the top right-hand corner of the app.
Figure 7: Change Camera Button in Windows Camera App
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2.2.2 Register a Face
To make full use of the face detection and recognition features of the SLN-VIZNAS-IOT,
you must register a face. To begin registering a new face, press the Manual Registration
button on the kit (SW4).
Figure 8: SLN-VIZNAS-IOT Manual Registration Button
Once pressed, a message indicating registration is taking place will appear at the top of
the screen, and the bounding box around the user’s face will turn from blue to green. To
register your face, stare straight-on at the camera while aligning your face inside the
bounding box. While registration is taking place, a “Registering” message will be shown.
Figure 9: Registration in Progress
NOTE: If pressing the button does not produce a “Registering” message, ensure that the “base”
board and “expansion” board are properly connected inside of the enclosure.
To cancel registration, simply press the registration button again, or, wait for the
registration process to timeout (~5s).
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Once successfully registered:
•
•
•
A “USERNAME Added” message will be displayed
The number of registered users will increase by one
A username will be assigned to the registered face (usernames can be specified
through the CLI interface discussed in the following section)
Figure 10: Successful Registration
Should your face fail to register properly, either due to the registration being canceled or
timing out, a message like the following will be displayed:
Figure 11: Registration Failed
To retry, simply press the manual registration button again.
NOTE: If you are having trouble successfully registering a face, try adjusting proximity to the camera (either
closer or further away), slowly moving your head left-right and up-down so that the camera can get a better
view of different angles of your face, and ensure that the face being registered is sufficiently well lit for both
the IR and RGB cameras by adjusting the pwm values for the IR and white LEDs. For more information, check
out the Troubleshooting section near the end of this guide.
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Once registered, recognition of your face will prompt a “Welcome Home” message,
indicating the kit has detected a recognized face.
Figure 12: "Welcome Home" Message
Your face will continue to be recognized so long as the system is running. By default,
however, faces will be erased upon reset and must be explicitly saved into flash using the
“save” command if they should be retained (see Save Users Through Resets).
2.2.3 Liveness Detection and Anti-Spoofing
The SLN-VIZNAS-IOT comes with Liveness Detection and Anti-Spoofing turned ON
by default, meaning that the system can discern between your actual face and a printout/phone display picture of your face.
Figure 13: Phone Display Spoof Attack
By requiring a user’s actual face to be able to unlock the system, as opposed to a simple
picture of the user’s face, this feature helps to protect against some of the most common
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face recognition “spoof” attacks wherein a malicious actor will use a picture of someone
to gain access to their face-protected materials.
Figure 14: Printed Picture Spoof Attack
As shown in the screenshots above, using neither a phone display nor a printed picture
of a face triggers the “Welcome Home” message. In fact, if we enable verbose mode (see
2.2.5 Enable Verbose Mode) while attempting to recognize the printed picture in Figure
14, we can see that the inference engine detects a face, but recognizes that the image
captured by the IR camera is a “fake”/”spoofed” face.
Figure 15: Fake Face Detected
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2.2.4 Connect to Serial CLI
Using serial commands will give users access to the full suite of features the SLNVIZNAS-IOT has to offer. Issuing serial commands can be done via a serial terminal
emulator like PuTTY or Tera Term.
To connect to the serial CLI of the kit, identify the COM port associated with the kit and
connect using the [115200, 8, 1, N, XON/XOFF] serial settings shown below.
Figure 16: Serial Connection Settings
After connecting to the kit’s serial interface, you will encounter a blank terminal screen
that echoes any characters that you type. Use the “help” command to display a list of all
the available serial commands and their usage. We will be discussing a few of these
commands in the upcoming sections.
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SHELL>> help
"help": List all the registered commands
"exit": Exit program
"list": List all registered users
"add username": Add user
"add -s": Stop the former add command issued
"del username": Delete user
"del -a": Delete all users
"rename oldusername newusername": Rename user
"verbose (none-all)": Debug message detail level setting
"camera ir_pwm ": PWM pulse width for IR led, value should be between 0 (inactive) to 100
"camera white_pwm ": PWM pulse width for white led, value should be between 0 (inactive) to 100
"version": The version information
"save n": Save database into flash memory
"updateotw": Reboot the board and start the OTW firmware update
"reset": Reset the MCU
"emotion "
"liveness "
"detection resolution ": Set detection resolution and reset
"display output_mode "
"display output_device "
"display interface "
"wifi ": Turn the Wi-Fi connection on|off
"wifi reset": Reset wifi to re-link.
"wifi credentials": Get the credentials.
"wifi credentials SSID [PASSWORD]": Set Wi-Fi credentials.
"wifi ip": Get the ip address.
"wifi erase": Erase the Wi-Fi credentials from flash
"app_type ":
0 - Elock(light)
1 - Elock(heavy)
2 - Door access(light)
3 - Door access(heavy)
4 - Userid
"low_power ": Turn low power mode on|off
Figure 17: Serial Commands "Help" Menu
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2.2.5 Enable Verbose Mode
The SLN-VIZNAS-IOT kit supports debug message logging which provides important
inference performance information, for example, the time it took to detect a user. Serial
debug messages are disabled by default but can be enabled via a serial command.
To enable serial debug output, type the serial command “verbose 0”, “verbose 1”,
“verbose 2”, or “verbose 3.”
Figure 18: "verbose 0"
Using the verbose command will enable logging of the debug information indicated in
the table below.
“verbose 0”
“verbose 1”
“verbose 2”
“verbose 3”
X
X
X
X
X
Message Type
Importance
Critical
High
Detailed
Medium
Misc.
Low
X
On-screen
Debug Info
N/A
X
Table 3: Verbose Mode Configuration Table
The following is an example of a debug message a user might receive after a face
detection and recognition event.
Figure 19: Example Verbose Mode Debug Message
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The following table describes the different messages and the associated descriptions.
Abbreviation
Definition
dt
Time taken to detect face
rt
Time taken to recognize face
sim
Predictive accuracy/confidence value of face rec
face_id
Internal face database identifier
Table 4: Verbose Mode Abbreviation Table
In addition to debug logging over serial, enabling “verbose 3” will also display some
useful on-screen information as well that can be helpful when troubleshooting
registration/recognition issues. An example can be seen in the images below:
NOTE: Without any registered users, the on-screen debug info will not update until a registration
has been triggered. This is because the inference engine does not attempt to recognize any faces
if they are none currently registered.
Figure 20: On-screen Info for Registering Face
In the above example, registration is taking place, but according to the on-screen
debugging info, although the face has passed the blurriness check (hence “blur: 0”), the
“front face check” has passed (hence “front: 1”), and the RGB liveness check has
passed (hence “rgbLive: 1”), the IR liveness check has not passed (hence “irLive: 0”).
This would suggest that there may be an issue with the IR camera – likely a lighting issue.
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Figure 21: On-screen Info for Recognized Face
In this example, the on-screen info reflects information about the face being recognized.
As shown in the screenshot, the face has been recognized with 95% similarity to the
matching face in the internal database (hence “sim: 95”) and has passed both the RGB
and IR liveness checks (hence “rgbLive: 1” and “irLive: 1”).
NOTE: The “front face check” is only performed by the inference engine for faces being registered
to ensure that no face gets registered that it is improperly angled towards the camera. For this
reason, the “front” value will not change unless a registration is being performed.
2.2.6 (Optional) Enable Low Power Mode
For many use cases, managing power consumption is critical. Fortunately, the SLNVIZNAS-IOT supports low power features out-of-the-box. Low power mode functionality
can be enabled or disabled through the use of the serial commands.
Use the command “low_power on” or “low_power off” to enable or disable the low
power mode feature supported on the SLN-VIZNAS-IOT.
SHELL>> low_power on
SHELL>> Low power mode enabled.
When low power mode is enabled, the SLN-VIZNAS-IOT will automatically
sleep/hibernate in a state of much lower power consumption than normal, when no
registration/deregistration is taking place and no activity is detected by the camera for
~20s. A “recognition timeout” message like the one shown in Figure 22 will be displayed
on screen as a warning that the SLN-VIZNAS-IOT will be entering sleep mode within the
next 5 seconds.
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Figure 22: "Recognition Timeout" Message
During hibernation, nearly everything but a select few peripherals is disabled in order to
conserve power. As a result, the video output from the kit as well as the shell interface
will not be active and will not be accessible until the board has woken up again.
NOTE: When low power mode is activated and the board enters sleep/hibernation, after the SLNVIZNAS-IOT wakes up, your computer’s camera app (Windows Camera app, Cheese, etc.) may need
to be restarted before you can begin seeing camera output once again. This may also apply to your
serial terminal emulator of choice as well (PuTTY, Tera Term, etc.)
Because only select peripherals are enabled during sleep mode, the SLN-VIZNAS-IOT
will only wake up in response to a specific trigger(s), which by default, is the SW3 push
button shown in the following figure:
Figure 23: Hibernation Wake-up Trigger (SW3)
Upon detecting the trigger, the SLN-VIZNAS-IOT will automatically wake up and begin
running as normal.
For more specifics on low power mode, check out Low Power Mode.
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3 Additional Features
This section will discuss in more detail some of the extra features included in the kit that
may not have been discussed in the previous sections. Included in this feature discussion
are the Push Buttons and their functionality, each of the supported Serial Commands
and how to use them, Remote (Wireless) Registration, App Configurations, Low Power
Mode, Audio Feedback, and the Configurable Display settings.
Button
Function
Description
SW1
Toggle GUI
Toggles the GUI on or off.
SW2
Manual Deregister
Triggers the deletion of the
next registered face
encountered by the kit.
SW3
Toggle IR/RGB Output
Toggles whether output
from the RGB or IR
camera is shown. Does not
affect which cameras are
in use.
SW4
Manual Register
Triggers registration of the
next face encountered by
the kit.
Table 5: Push Buttons Functionality
3.1 Push Buttons
The SLN-VIZNAS-IOT kit makes use of on-board push buttons in order to give users easy
access to some of the kit’s most useful features, like face registering and deregistering,
and the ability to change between manual and automatic enrollment mode.
In this section, we will discuss these buttons and their functions in more depth.
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3.1.1 SW1 – Toggle GUI
Figure 24: SW1
The SW1 push button toggles the GUI ON or OFF. When the GUI is deactivated, only
video from the kit’s camera will be shown and no other on-screen information.
Figure 25: GUI Toggled Off
NOTE: The behavior of this button is identical to that of the “display interface” serial command.
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3.1.2 SW2 – Manual Deregistration
Figure 26: SW2
Working similarly to SW4, pressing SW2 will trigger a manual “deregistration” command,
which will remove the next recognized face from the kit’s internal face database.
When this button is pressed, an indicator message will be displayed at the top of the
screen which lets the user know that the process of deregistering a face is taking place.
Figure 27: Deregistration in Progress
To deregister a face, simply stare straight-on at the camera while aligning the face inside
the bounding box for ~1-3 seconds and wait for a message confirming the removal of the
user. Once deregistered, the number of registered users will be decremented by one.
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Figure 28: "USERNAME Removed" Message
Should the deregistration process fail, a “Remove Failed” message will be displayed.
Simply press the SW2 push button again to retry.
Figure 29: "Remove Failed"
To cancel a deregistration, simply press the deregistration button again, or, wait for the
deregistration process to timeout (~5s).
NOTE: The behavior of this button is identical to specifying the name of the user whose face is
being captured by the camera as the argument to the “del USERNAME” command.
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3.1.3 SW3 – Toggle IR/RGB Output
Figure 30: SW3
When using all but the userid app type (see App Configurations), both cameras are
always active, however only the output from one camera can be displayed at a time. The
SW3 push button can be used to toggle between the output coming from the IR and RGB
cameras as shown in the following figure.
Figure 31: SW3
The behavior of SW3 is identical to that of the “display output_mode ”
command.
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3.1.4 SW4 – Manual Registration
Figure 32: SW4
As mentioned previously, the SW4 push button can be used to trigger the manual
registration process.
Once pressed, a message indicating registration is taking place will appear at the top of
the screen, and the bounding box around the user’s face will turn from blue to green. To
register your face, stare straight-on at the camera while aligning your face inside the
bounding box. While registration is taking place, a “Registering” message will be shown.
Figure 33: Registration in Progress
NOTE: If pressing the button does not produce a ‘Registering’ message, ensure that the “base”
board and “expansion” board are properly connected inside of the enclosure.
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To cancel registration, simply press the registration button again, or, wait for the
registration process to timeout (~5s).
Once successfully registered:
•
•
•
A “USERNAME Added” message will be displayed
The number of registered users will increase by one
A username will be assigned to the registered face (usernames can be specified
through the CLI interface discussed in the following section)
Figure 34: Successful Registration
Should your face fail to register properly, either due to the registration being canceled or
timing out, a message like the following will be displayed:
Figure 35: Registration Failed
To retry, simply press the manual registration button again.
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Once registered, recognition of your face (done simply by placing your face in front of the
camera for a brief moment) will prompt a “Welcome Home” message, indicating the kit
has detected a recognized face.
Figure 36: "Welcome Home" Message
Simply follow the same procedure to add additional faces into the system.
NOTE: If you are having trouble successfully registering a face, try adjusting your proximity to the
camera (either closer or further away), and additionally try slowly moving your head left-right and
up-down so that the camera can get a better view of different angles of your face. If after following
these instructions you are still experiencing trouble, ensure that the face being registered is
sufficiently well lit for both the IR and RGB cameras by adjusting the pwm values for the IR and
white LEDs. For more information, check out the Troubleshooting section near the end of this
guide.
3.2 Serial Commands
In order to access the full suite of features that the SLN-VIZNAS-IOT has to offer,
communication via serial is needed. Using serial, users can be added and deleted, the
camera’s detection resolution can be configured, as well as several additional capabilities.
In this section, we will show a full list of available serial commands and cover them indepth.
3.2.1 List Available Commands
To display a list of all available commands you can run, type the command “help.” This
command will output a list similar to that shown below which details all available
commands and their arguments:
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Command
Arguments
help
Display a list of all available serial commands along with
a brief description of their function
exit
Exit program; closes serial terminal until reset
list
List all registered users
add
USERNAME
add
-s
del
USERNAME
del
-a
rename
Old new
Renames face associated with old name to new name
verbose
Configures verbose mode debug logging with the
specified verbosity
camera ir_pwm
< 0 – 100 >
Configures the camera adapter’s IR LEDs to use the
specified intensity
camera white_pwm
< 0 – 100 >
Configures the camera adapter’s white LEDs to use the
specified intensity
Add new user with specified username
Stops attempting to add a new user
Deletes specified user
Deletes all registered users
Displays
engine
version
save
version information
regarding
inference
Saves face database in flash memory
Reboots the board and sets up OTW firmware update
mode
updateotw
reset
30
Description
Reset the MCU
Configures emotion recognition to use the specified
mode (0, 2, 4, or 7 emotion recognition mode)
emotion
liveness
< on | off >
detection resolution
< qvga | vga >
Configures the detection resolution to use the resolution
specified and resets the board
display output_mode
< rgb | ir >
Configures whether output from the rgb camera or the
ir camera is shown
display output_device
< usb | riverdi >
Configures the display output device to use either video
over USB or the Riverdi display. (Requires Riverdi
display)
Enables or disables liveness detection
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display interface
< loopback | infobar >
wifi
wifi reset
Turn the Wi-Fi connection on or off
Reset Wi-Fi to reestablish connection
wifi credentials
wifi credentials
Configures whether the info bar/GUI is displayed or not
Get the current Wi-Fi credentials (SSID and password)
[SSID] [PASSWORD]
wifi ip
Set Wi-Fi credentials
Return the current ip address.
wifi erase
Erase the Wi-Fi credentials from flash
0-Elock(light)
app_type
1-Elock(heavy)
Determines the inference engine model to use. For
descriptions of these models see
2-Door access(light)
3-Door access(heavy)
low_power
< on | off >
Enables or disables low power mode
Table 6: Serial Command Table
3.2.2 List All Registered Users
Using the “list” command will list all the users currently registered into the system.
SHELL>> Registered users count:2
Cooper
Chris
Figure 37: "list" Command
3.2.3 Manually Add Users
While running in manual mode, in order to register a new face, use the command “add
USER_NAME.” After a few seconds, should the demo find a face, it will begin recording
and saving a face, with success indicated by a green border around the newly registered
face.
SHELL>> add Cooper
SHELL>> Start registering ‘Cooper’
Figure 38: "add Cooper" Command
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To cancel an “add” command issued via serial or the SW4 push button, issue an “add”
command with the “-s” argument.
SHELL>>
SHELL>>
SHELL>>
SHELL>>
add Cooper
Start registering ‘Cooper’
add –s
Stopped adding
Figure 39: "add -s" Command
3.2.4 Manually Delete Users
In cases where you want to delete a previously registered user, running the command
“del USER_NAME” will delete the specified user.
SHELL>> del Cooper
SHELL>> User ‘Cooper’ successfully deleted
Figure 40: "del Cooper" Command
Alternatively, running the command “del -a” will delete all users from the database.
SHELL>> del -a
SHELL>> All users successfully deleted
Figure 41: "del -a" Command
3.2.5 Rename Users
The “rename” command can be used to rename a user who is currently registered into
the database. To do so, simply use the command “rename oldusername
newusername.” Below is an example of the command being used.
SHELL>> rename user_0 Cooper
SHELL>> User ‘user_0’ successfully renamed
Figure 42: "rename user_0 Cooper" Command
3.2.6 Verbose Mode
The SLN-VIZNAS-IOT kit supports debug message logging which provides important
inference performance information, for example, the time it took to detect a user. Serial
debug messages are disabled by default but can be enabled via a serial command.
To enable serial debug output, type the serial command “verbose 0”, “verbose 1”,
“verbose 2”, or “verbose 3.”
SHELL>> verbose 3
SHELL>> Verbose level set to 3
Figure 43: "verbose 0"
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Using the verbose command will enable logging of the debug information indicated in
the table below:
“verbose 0”
“verbose 1”
“verbose 2”
“verbose 3”
X
X
X
X
X
Message Type
Importance
Critical
High
Detailed
Medium
Misc.
Low
X
On-screen
Debug Info
N/A
X
Table 7: Verbose Mode Configuration Table
The following is an example of a debug message a user might receive after a face
detection and recognition event.
Figure 44: Example Verbose Mode Debug Message
The following table describes the different messages and the associated descriptions.
Abbreviation
Definition
dt
Time taken to detect face
rt
Time taken to recognize face
sim
Predictive accuracy/confidence value of face rec
face_id
Internal face database identifier
Table 8: Verbose Mode Abbreviation Table
In addition to debug logging over serial, enabling “verbose 3” will also display some
useful on-screen information as well that can be helpful when troubleshooting
registration/recognition issues. An example can be seen in the images below:
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Figure 45: On-screen Info for Registering Face
NOTE: Without any registered users, the on-screen debug info will not update until a registration
has been triggered. This is because the inference engine does attempt to recognize any faces if
they are none currently registered.
In the above example, registration is taking place, but according to the on-screen
debugging info, although the face has passed the blurriness check (hence “blur: 0”), the
“front face check” has passed (hence “front: 1”), and the RGB liveness check has
passed (hence “rgbLive: 1”), the IR liveness check has not passed (hence “irLive: 0”).
This would suggest that there may be an issue with the IR camera – likely a lighting issue.
Figure 46: On-screen Info for Recognized Face
In the above example, the on-screen info reflects information about the face being
recognized. As shown in the screenshot, the face has been recognized with 95% similarity
to the matching face in the internal database (hence “sim: 95”) and has passed both the
RGB and IR liveness checks (hence “rgbLive: 1” and “irLive: 1”).
NOTE: The “front face check” is only performed by the inference engine for faces being registered
to ensure that no face gets registered that it is improperly angled towards the camera.
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3.2.7 Configure IR LED Brightness
The dual camera adapter has two IR LEDs which can be configured to control their
brightness as appropriate for the environment they are being used in. To control the
brightness, these IR LED’s use PWM signals which have configurable duty cycles that
can be set using serial commands.
To control the brightness of the LED, use the command “ir_pwm 0-100” to set the
percentage brightness of the LEDs. An example of this command being run is shown
below.
SHELL>> ir_pwm 60
SHELL>> Camera IR duty cycle 60%
Figure 47: "ir_pwm 60" Command
NOTE: If not using a camera which supports configurable IR LEDs, you will receive a message like
the following:
SHELL>> ir_pwm 60
SHELL>> Camera IR PWM not supported
Figure 48: "Camera IR PWM not supported" Message
3.2.8 Configure White LED Brightness
The dual camera adapter has two white LEDs which can be configured to control their
brightness as appropriate for the environment they are being used in. To control the
brightness, these white LEDs use PWM signals which have configurable duty cycles that
can be set using serial commands.
To control the brightness of the LED, use the command “white_pwm 0-100” to set the
percentage brightness of the LEDs. An example of this command being run is shown
below.
SHELL>> white_pwm 60
SHELL>> Camera white duty cycle 60%
Figure 49: "ir_pwm 60" Command
3.2.9 Print Version Information
It can be useful to know which version of the SLN-VIZNAS-IOT inference engine is being
run in order to know which features are currently supported. To determine the version
number of the Oasis Lite inference engine being used by your kit, use the “version”
command.
SHELL>> version
SHELL>> Engine:v3.4
Figure 50: "version" Command
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3.2.10
Save Users Through Resets
When low power mode is disabled, faces are not automatically saved into flash, meaning
that when the board is reset, any registered faces not explicitly saved into flash will be
removed. To save a face into flash, use the command “save N”, where “N” is the number
of users you want to save. Users are saved in the order that they were added, so if the
command “save 3” was used, the first 3 users registered into the database would be
saved.
SHELL>> save 3
SHELL>> 3 list will be saved into flash database
Database save success. Time taken in ms 0
Figure 51: "save 3" Command
Alternatively, the command “save” with no arguments will save all registered users into
flash.
SHELL>> save
SHELL>> all sdram database will save into flash database
Database save success. Time taken in ms 0
Figure 52: "save" Command
The “save” command returns a success message along with the time taken in
milliseconds to save all the faces into flash.
3.2.11
Enable OTW (Over-the-Wire) Update Mode
OTW updates and enabling OTW Update Mode are discussed in the SLN-VIZNAS-IOT
Developer’s Guide.
3.2.12
Reset the SLN-VIZNAS-IOT
Situations can arise in which it is useful to reset the kit without needing to physically power
cycle the kit. This can be done through use of the “reset” command. This command
performs a soft reset of the kit, going through the entire bootstrapping and bootloading
process (see SLN-VIZNAS-IOT-Developer’s Guide) again.
SHELL>> reset
SHELL>> System will reset
Figure 53: "reset" Command
As with any reset of the kit, serial communication will need to be reestablished to begin
issuing serial commands to the board again and you may also need to restart the camera
application you are using (Windows Camera App, Cheese, etc..
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3.2.13
Configure Emotion Recognition
The SLN-VIZNAS-IOT kit supports emotion recognition in addition to face recognition.
This feature comes disabled by default and needs to be enabled via serial commands.
Once connected to the kit via serial, use the command “emotion 0”, “emotion 2”,
“emotion 4”, or “emotion 7.”
SHELL>> emotion 4
SHELL>> 4 types emotion recognition is set, system will reset
Figure 54: "emotion 4" Command Success Output
Running the “emotion” command will enable the recognition of the emotions shown in
the table below.
Emotion
“emotion 2”
“emotion 4”
“emotion 7”
Neutral
X
X
X
Happy
X
X
X
Angry
X
X
Surprised
X
X
Sad
X
Fear
X
Disgust
X
Accuracy
92%
81%
62%
Table 9: Emotion Recognition Configuration Table
When a user’s emotion is recognized, the kit will display a message which will indicate
the detected emotion. If a user smiles, the text “Happy” will be shown in the upper righthand corner of the bounding box*.
*Note: Detected emotion will only be shown through verbose mode when the app type is not the
UserID app type. For more info on app types/configurations see App Configurations.
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Figure 55: "emotion 4"
The more emotions that are being actively recognized, the lower the emotion accuracy.
For this reason, we recommend using two or four emotions.
Please note the “Neutral” emotion is a standard state and is not displayed.
3.2.14
Configure Liveness Detection
Kits equipped with the dual camera adapter come with the ability to perform liveness/antispoofing detection as an added level of security for those using the kit. This feature comes
enabled by default.
Using the command “liveness ” can be used to toggle this feature off or on. For
the command to take effect, the board will automatically reset itself, so make sure you
have any faces you want to retain saved in flash.
Figure 56: "liveness off" command
Figure 57: "liveness on" Command
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3.2.15
Configure Detection Resolution
The SLN-VIZNAS-IOT kit comes with both VGA and QVGA detection resolution
settings*. By default, the kit runs in VGA mode. Although VGA takes more processing
power which can slightly affect detection times, the higher resolution provided by VGA
mode also allows for further roughly double detection/recognition range compared to
using QVGA. An overview of the differences can be seen in the chart below.
NOTE: As the name would suggest, changing the detection resolution does not affect the resolution
of the video output, just the resolution of the image passed to the inference engine.
Mode
Resolution
Detection &
Recognition Range
Detection Speed
VGA (default)
640x480
.3m ~1.4m
100ms
QVGA
320x240
.3m ~ .7m
80ms
Table 10: VGA vs. QVGA
A visual example of the difference in max range between the two resolutions can be seen
in the following figure:
Figure 58: VGA vs. QVGA Detection Resolution Max Range
In order to switch between the two modes, the command “detection resolution
” can be used to enable VGA or QVGA detection resolution mode. For the
command to take effect, the board will automatically restart itself, so make sure to have
any faces you want to retain saved in flash (see Saving Users Through Resets).
SHELL>> detection resolution vga
SHELL>> Detection resolution VGA mode selected, reset system
Figure 59: "detection resolution vga" Command
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SHELL>> detection resolution qvga
SHELL>> Detection resolution QVGA mode selected, reset system
Figure 60: "detection resolution qvga" Command
NOTE: Due to the minimal benefits in detection performance, VGA is recommended for most usecases.
3.2.16
Display IR Output
The camera whose output gets displayed can be configured via the “display ”
command which will configure the display to output from whichever camera is specified.
The functionality of this command is identical to that of the SW3 push button.
SHELL>> display output_mode ir
SHELL>> display ir frame
Figure 61: "display output_mode ir" Command
Figure 62: IR Display Output
SHELL>> display output_mode rgb
SHELL>> display rgb frame
Figure 63: "display mode not supported" Message
NOTE: This command will only change the camera being shown, not the camera(s) being used for
detection and recognition.
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3.2.17
Configure Display Output Device (Requires Riverdi Display)
Kits enabled with a Riverdi display like that shown below can use the “display
output_device ” command to configure whether video will be output
through USB to a computer or through the Riverdi display connected to the kit.
Figure 64: Riverdi Display
SHELL>> display output_device riverdi
SHELL>> Display output mode set to riverdi, system will reset
Figure 65: "display output_device riverdi" Command
For more information on supported display peripherals, see Display Configurations
3.2.18
Toggle GUI
The “display interface ” command can be used to toggle the GUI
on or off, leaving only the face bounding box. The behavior of this command is identical
to that of the SW1 push button.
SHELL>> display interface loopback
SHELL>> Interface changed with success
Figure 66: "display interface loopback" Command
Figure 67: GUI Toggled Off
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3.2.19
Toggle Wi-Fi Enablement
The command “wifi ” can be used to turn Wi-Fi functionality either on or off.
The output of this command is based on the connection status of the Wi-Fi.
For example, if Wi-Fi was off before issued the “wifi on”, you will get output like the
following:
SHELL>> wifi on
SHELL>> Wi-Fi will start
Figure 68: "Wi-Fi will start" Message
Alternatively, if this command is used while the Wi-Fi is already attempting to connect,
you will get the following message:
SHELL>> wifi on
SHELL>> Wi-Fi driver is connecting, wait...
Figure 69: "Wi-Fi driver is connecting" Message
If the Wi-Fi is already turned on and connected, you will receive the following message:
SHELL>> wifi on
SHELL>> Wi-Fi driver is on
Figure 70: "Wi-Fi driver is on" Message
Finally, if the Wi-Fi was already on and had attempted to connect but failed because the
credentials given were bad, etc., you will receive the following message:
SHELL>> wifi on
SHELL>> Wi-Fi is in provisioning mode
Figure 71: "wifi on" Command
The “wifi off” command will display a message like the following if Wi-Fi is currently on
SHELL>> wifi off
SHELL>> Wi-Fi will stop
Figure 72: "Wi-Fi will stop" Message
or a message indicating that the Wi-Fi is already off:
SHELL>> wifi off
SHELL>> Wi-Fi driver is off
Figure 73: "Wi-Fi driver is off" Message
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3.2.20
Reset Wi-Fi
The command “wifi reset” can be used to reset the kit’s connection to the network.
Resetting the network can be useful in scenarios where the kit has lost connection to its
network, but performing a Wi-Fi reset is also necessary any time the Wi-Fi credentials are
updated.
SHELL>> wifi reset
SHELL>> Wi-Fi will reset
Figure 74: "wifi reset" Command
3.2.21
Retrieve Wi-Fi Credentials
If Wi-Fi credentials have already been configured on the kit either through the CLI
interface or through the remote provisioning application, using the command “wifi
credentials” will retrieve both the SSID and password credentials which are currently in
use.
SHELL>> wifi credentials
SHELL>> SSID is test_ssid with password 123456.
Figure 75: "wifi credentials" command
If no credentials are currently in use, the output of the command will look like the following:
SHELL>> wifi credentials
SHELL>> Wi-Fi Credentials not found
Figure 76: "Wi-Fi Credentials not found" Message
NOTE: While useful during development, exposing sensitive password information is not
recommended, and it is advised that this command be disabled.
3.2.22
Configure Wi-Fi Credentials
The “wifi credentials SSID PASSWORD” command can be used to configure the Wi-Fi
settings being used by the kit.
SHELL>> wifi credentials test_ssid 123456
SHELL>> Wi-Fi credentials set. New network will be available after WiFi reset
Figure 77: "wifi credentials" w/ Args
To begin using the newly configured Wi-Fi settings, a Wi-Fi reset must be issued either
through a reset of the board or via the “wifi reset” CLI command discussed previously.
Failure to properly specify both an SSID and password will result in output like the
following:
SHELL>> wifi credentials test_ssid
SHELL>> Wrong command for wi-fi credentials
Figure 78: "wifi credentials" w/ Bad Arg
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3.2.23
Retrieve IP Address
Once the Wi-Fi credentials have been set, the IP address associated with the kit’s Wi-Fi
connection can be discovered using the “wifi ip” command. Assuming the board is
connected to a network, the command should display output similar to the following:
SHELL>> wifi ip
IPv4 Address: 192.168.0.165
Figure 79: "wifi ip" Command Successful
If no connection to a network has been made, the IP address returned by the command
will be “0.0.0.0”
SHELL>> wifi ip
IPv4 Address: 0.0.0.0
Figure 80: "wifi ip" Command Unsuccessful
3.2.24
Erase Wi-Fi Credentials
In order to completely erase the existing Wi-Fi credentials, use the “wifi erase”
command.
SHELL>> wifi erase
SHELL>> Wi-Fi credentials removed
Figure 81: "wifi erase" Command
NOTE: Once issued, the Wi-Fi credentials will be wiped from flash and cannot be retrieved.
3.2.25
Configure Application Type
The “app_type ” CLI command can be used to configure the “App Type” used
by the inference engine. The arguments in the command correspond to the following app
types:
Number/Argument
Corresponding App Type
0
E-Lock (Light)
1
E-Lock (Heavy)
2
Door Access (Light)
3
Door Access (Heavy)
4
Userid
Table 11: App Type Arguments
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SHELL>> app_type 0
SHELL>> Set app type 0, system will remove existing db & reset.
Figure 82: "app_type" Command
NOTE: As the output of the command shown in the figure above would suggest, the current
database of registered faces is erased whenever the app type is configured. This is due to the
incompatibility of data from one model/app type with another.
More information about App Types can be found in the App Configurations section.
3.2.26
Configure Low Power Mode
As discussed in an earlier section, the command “low_power ” can be used to
configure whether low power/the ability to enter sleep mode is enabled or disabled.
SHELL>> low_power on
SHELL>> low_power enabled
Figure 83: "low_power on" Command
More information about low power mode can be found in the Low Power Mode section.
3.3 Remote (Wireless) Registration
The SLN-VIZNAS-IOT supports the ability to register faces both locally by using either
CLI commands or the on-board push buttons as described in earlier sections, but it also
supports remote registration via BLE using an Android phone/tablet application. The
companion remote registration Android app, also known as the “FaceRec Manager”
application, sports a relatively simple interface where a user is able to register faces
remotely and manage the users stored in the SLN-VIZNAS-IOT’s local database. This
section will discuss some of the major features provided by this application.
A download link for the FaceRec Manager Android APK + full source code can be found
under the Software and Tools section of the homepage for the SLN-VIZNAS-IOT.
NOTE: The FaceRec Manager application is intended for use as an evaluation tool, and as a
reference/boiler plate upon which a customized smartphone/tablet companion application can be
built on top of.
3.3.1 Select Wireless Configuration
The FaceRec Manager application gives the option for remote registration over BLE or a
Network* (Wi-Fi) connection. To select the desired configuration, simply choose your
preferred option from the app’s home screen, which will look similar to the screen shown
below:
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Figure 84: FaceRec Manager Home Screen
**NOTE: Currently only remote registration via BLE is supported
3.3.2 Connect Kits
Through the FaceRec Manager application, users are able to add kits they own by simply
pressing a button to scan for remote devices that are within Bluetooth range of the
phone/tablet being used.
Figure 85: "Smart Locks" Management Page
Once scanning has begun, any devices in the area will automatically be detected and
show up in the app as a potential connection. Simply press “Connect” next to the device
you want to add in order to register the VIZNAS kit to your list of kits being managed.
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Figure 86: BLE Connections in Range
After connecting with the device, a unique name and passcode can be associated with
the kit to demonstrate how an end-device could be identified and management of that
device could be restricted via password protection.
Figure 87: Configure SmartLock Information
Finally, your registered locks will show up under the “Manage Smart Locks” tab inside the
Android app, and the kit your phone/tablet is currently connected to will display a BLE
icon indicating a connection is currently established with that SLN-VIZNAS-IOT kit.
Additionally, users can connect/disconnect from a device using the BLE icon in the upper
right-hand corner of the screen, and using a simple swipe gesture, an individual lock can
be renamed or deleted entirely.
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Figure 88: "Manage Smart Locks" Tab
Figure 89: Connected Locks
NOTE: Currently, only one device can be “managed”/connected to at any given time.
3.3.3 Manage Users
The FaceRec Manager app, as the name would imply, allows users to manage the
users stored on an SLN-VIZNAS-IOT kit using an Android application. This includes the
ability to add, list, and delete users from the SLN-VIZNAS-IOT’s local face database by
providing 2-way synchronization. This section will give an overview of each of these
features.
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3.3.3.1 Add Users
One of the highlights of FaceRec Manager application is the ability to remotely register
faces via Wi-Fi* or BLE. The application provides a simple interface for adding faces
which can be accessed under the “Manage Users” tab.
Figure 90: Remote Registration Screen
To register your face, click on the icon of silhouette in upper-middle part of the screen.
Once pressed, a screen like the following will be shown and you must enable face
capture by using the camera icon at the bottom of the screen:
Figure 91: Remote Face Capture Screen
The “face capture” screen may provide instructional cues to help you properly align your
face, etc. and will automatically return to the previous screen once your face has
successfully been registered.
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3.3.3.2 List Users
In addition to adding users, a full list of users registered to a device can be seen under
the “Manage Users” tab in the FaceRec Manager Android application.
Figure 92: "Manage Users" Tab
From here, pulling down from the middle of the page will perform a sync between the
device and the application. Alternatively, individual users registered remotely but not yet
synced with the kit can be synced by clicking the “sync icon” next to a user’s name.
Figure 93: User List Screen
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3.3.3.3 Delete Users
In addition to adding and listing users, the FaceRec Manager application also allows for
the deletion of registered users as well. From the “Manage Users” tab, swiping left on the
name of the user who is to be deleted will reveal an icon which allows for the deletion of
the user.
.
Figure 94: Remote Deletion Screen
3.4 Remote Credential Provisioning
In addition to the FaceRec Manager App, the SLN-VIZNAS-IOT also comes with a
reference application for remote credential provisioning over Wi-Fi and BLE call the VIZN
Companion App. This application allows users to remotely provide Wi-Fi credentials
using an existing Wi-Fi connection or via BLE. Similar to the FaceRec Manager App, the
APK + full source code for this Android application can be downloaded from the official
webpage for the SLN-VIZNAS-IOT under the Software and Tools section. While the
functionality for this application is limited, it is intended to be used as a reference for
developers seeking to create their own smartphone/tablet companion applications.
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3.5 App Configurations
The below table shows a list of the different available app types and their corresponding
feature sets. In this section, each of these app types will be looked at in more depth to
highlight the advantages and disadvantages of each.
App Type
Max # of
Faces
Detection
Speed
Recognition
Speed
Liveness Detection &
Anti-Spoofing
E-Lock (Light)
50
~80ms
~200 ms
Yes
E-Lock
(Heavy)
100
~80ms
~700 ms
Yes
Door Access
(Light)
1000
~80ms
~200 ms
Yes
Door Access
(Heavy)
3000
~80ms
~700 ms
Yes
Userid
1000
~80ms
~200 ms
No
Table 12: App Configurations
As shown in the table above, the various app type configurations greatly affect the
recognition speed, number of faces, and security functionality of the kit. Each app type
has its own advantages and disadvantages.
3.5.1 Light vs. Heavy
As shown in Table 12: App Configurations, E-Lock (Light) is roughly 500ms faster at
recognizing a face when compared to the E-Lock (Heavy) app type. However, the heavy
configuration is capable of recognizing roughly double the number of faces as the “light”
app type. A similar tradeoff between recognition speed and max # of faces can be seen
in the Door Access (Light) vs. Door Access (Heavy) models.
The disparity between the two comes down to the difference in the AI model which is
used to perform the recognition stage of the inferencing pipeline. The light models are
designed to recognize faces more quickly, but are more limited in the total number of
faces that can be recognized, whereas the heavy models are optimized for the max
number of faces that can be recognized, resulting in slower recognition speed than the
light models.
Choosing between the heavy and light model configurations comes down to a question
of performance vs. # of users, and that is generally determined by the use-case.
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3.5.2 E-Lock vs. Door Access vs. UserID
Both the E-Lock and Door Access and app types have liveness detection and antispoofing capabilities, however, the main difference between the two is a tradeoff
between max # of recognizable faces and power consumption.
Compared to the “Door Access” app type, the equivalent heavy/light E-Lock app can
recognize far fewer faces, but the advantage of using the E-Lock app type is that ELock utilizes the IR camera for face recognition as opposed to the RGB camera. While
the RGB camera provides more feature data, thereby allowing recognition of a far
greater number of faces, RGB struggles in lower-light conditions where an IR camera
has a much easier time. Because of this fact, the IR camera has less reliance on powerhungry illuminator LEDs that an RGB camera would require for the recognition process.
As a result, generally, the E-Lock app type is recommended in battery-powered usecases where continually running power-hungry LEDs could prove to be an issue,
draining a significant portion of the battery life.
The UserID app type, unlike the E-Lock and Door Access app types, does not have any
liveness detection/anti-spoofing features. The UserID app type is meant to replicate the
original SLN-VIZN-IOT kit which is no longer in active circulation. Unlike the original
SLN-VIZN-IOT kit, however, the remote registration and low power mode features of the
SLN-VIZNAS-IOT are fully functioning in this version of the UserID application. For
more information on the UserID app type, check out the User Guide for the SLN-VIZNIOT.
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3.6 Low Power Mode
Low power mode demonstrates the power saving capabilities of the RT106F chip, which
can be useful in battery-powered applications like a battery-powered door lock. While low
power mode is enabled, the SLN-VIZNAS-IOT kit will automatically go to sleep according
to the rules in the following diagram:
Figure 95: Low Power Timeout Flow
As shown above, when the kit boots and low power mode is enabled, two timers are
kicked off which are used to determine when the kit should fall asleep. One timer is used
only when a face is detected but not recognized, and the other timer is used when no face
is detected at all.
By default, the “No_Face_Timer,” which is used when no face is detected, will cause a
timeout and power down once 15 seconds have passed with no face detected. The
“Has_Face_Timer” is used when a face has been detected but is not recognized, and, by
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default, will timeout and power down after 25 seconds have passed with an unrecognized
face in frame.
Triggering a registration or deregistration will reset the “No_Face_Timer” and pause it
during the registration/deregistration so that neither of those processes will not be
interrupted by the system trying to go to sleep.
Once the system reaches the “Recognition Failed” state and is 5s from entering low power
mode, a “Recognition Timeout” message like the following will be prominently displayed
at the top of the screen as a warning that the system is about to power down.
Figure 96: "Recognition Timeout" Message
To prevent the erasure of registered faces when the board powers down, when low power
mode is enabled, registered faces are automatically saved into flash, unlike how faces
must be explicitly saved into flash upon reset when low power mode is disabled..
NOTE: Faces are not automatically saved to flash when low power mode is disabled.
Once asleep, the board can only be awoken by the triggers mentioned in Figure 95: Low
Power Timeout Flow: the PIR sensor*, SW3, and USB Power (Power Cycling the kit).
Triggering a wakeup will cause the board to return to normal operation.
**NOTE: The PIR sensor as a wakeup trigger is currently disabled on the SLN-VIZNAS-IOT due to a
manufacturing issue with the PIR sensor which causes unpredictable behavior when using the PIR
sensor as a wakeup source. This should not affect designs which use the PIR layout provided in
the SLN-VIZNAS-IOT HW schematic diagrams.
3.7 Audio Feedback
The SLN-VIZNAS-IOT comes with audio feedback prompts which are used alongside the
on-screen messages to provide information to the user. Currently, audio prompts for
“Registration Successful”, “Registration Failed”, and “Welcome” (Face Recognized) are
supported. To hear the audio prompts, a speaker must be soldered to the J3 connector
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which is connected to the TFA9894 audio amplifier on the kit. The location of the J3
connector is shown below:
Figure 97: J3 Speaker Connector
To disable audio prompts, the sln_viznas_iot_elock_oobe project must be recompiled
with the VOICE_PROMPT preprocessor macro set to 0. For more information on
configuring preprocessor macros see the SLN-VIZNAS-IOT Developer’s Guide.
3.8 Display Configurations
In addition to supporting video over USB, the SLN-VIZNAS-IOT can also display video
to an external display via SPI. Currently, the only officially supported display is the
Riverdi RVT28UEFNWC10 2.8” Capacitive Touch Display. More information about
this display can be found here.
Figure 98: Riverdi RVT28UEFNWC10
NOTE: The SLN-VIZNAS-IOT features a SPI interface to connect a Serial display from Riverdi,
which is supported by our Software Package. However, the MIMXRT106F also embeds a parallel
display controller which a customer could enable on their own board by leveraging existing NXP
drivers from the RT1060/RT1062 EVK package.
In order to make use of the display, 20-pin opposite-side contact ribbon cables like the
ones found here must be used*.
**NOTE: The picture associated with the item on the website does not accurately reflect the
opposite-side nature of the cable.
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To configure the display in use, simply specify either “usb” or “riverdi” as the argument to
the “display output_device” command (see 3.2.17 Configure Display Output Device
(Requires Riverdi Display)).
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4 Troubleshooting
4.1 Registering a Face
This section will describe steps that can be taken to help debug potential points of failure
when attempting to perform face registration and recognition. If after following these steps
you still cannot identify the cause of the issue, head over to the official NXP forums to
reach out for additional assistance.
4.1.1 Turn off Liveness Detection
First, to help identify whether the issue is with the detection/recognition or with the
liveness detection/anti-spoofing, turn off liveness detection using the “liveness off” CLI
command (see Configure Liveness Detection) to verify whether or not your face can be
registered without the secure features enabled.
If turning liveness detection off allows your face to able to be registered without any
issues, then the problem is likely related to the liveness detection and anti-spoofing
feature. Reenable liveness detection and skip to Debug Using Verbose Mode for
steps help identify what specifically is causing liveness detection to fail.
If turning liveness detection off still does not allow your face to be able to be registered,
follow the steps in Change App Type to help determine why detection/recognition is
failing.
4.1.2 Change App Type
As discussed in App Configurations, the E-Lock app type makes use of the IR camera
for detection/recognition while the Door Access app type makes use of the RGB camera
for detection/recognition. To help determine if there is an issue with one specific camera,
try changing from E-Lock to Door Access or vice versa depending on which configuration
you are currently using.
If after switching to the alternate app type, you are still experiencing an issue, proceed to
the next step.
4.1.3 Debug Using Verbose Mode
Verbose mode can provide useful information when debugging registration issues,
especially when it comes to debugging issues with liveness detection and anti-spoofing.
Follow the steps in the Enable Verbose Mode section of this guide and enable “verbose
3” to receive all available debugging information. The on-screen indicators can be
particularly helpful in identifying what is going wrong during registration.
For example, in the below screenshots we can see that the IR camera was falsely
detecting a fake face. This is likely due to a lighting issue which is covered in the next
section Ensure Lighting is Sufficient.
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Figure 99: "Registration Failed" + Verbose Mode Output
4.1.4 Ensure Lighting is Sufficient
One of the most common issues when registering a face is insufficient lighting for the IR
and/or RGB camera. Shown below are a few examples of insufficient lighting for the RGB
and IR cameras:
Figure 100: Bad RGB Lighting
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Figure 101: Bad IR Lighting
The “proper” lighting configuration can vary based on the environment in which the
product is being used and may therefore require tuning of the LED PWM settings via the
CLI commands discussed in Configure IR LED Brightness 3.2.6and Configure White
LED Brightness until a lighting setting which works for your environment is found.
4.1.5 Adjust Face Proximity and Position
Because face recognition makes use of face “identifiers” to determine the face being
looked at, it is important that these identifiers can be seen by both cameras. Oftentimes,
an improper face angle and/or the proximity to the camera can cause registration to fail.
Shown below are a few examples of improper usage.
Figure 102: Improper Face Angle & Proximity
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When attempting to register a face, the face should ideally take up a majority of the
bounding box, be centered inside the bounding box, and staring straight-on at the camera.
To help ensure the proper face angle is used, it can be helpful to slowly move the face
from left to right and up to down.
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5 Document Details
5.1 References
The following references are available to supplement this document:
Document/Link
Remark
http://www.nxp.com/MCUXpresso
MCUXpresso IDE Download
https://www.nxp.com/docs/en/userguide/MCUXpresso_IDE_User_Guide.pdf
MCUXpresso IDE User Guide
http://nww.preview.nxp.com/docs/en/userguide/SLN-VIZNAS-IOT-DG.pdf
SLN-VIZNAS-IOT Developer Guide
https://www.nxp.com/mcu-vision2
SLN-VIZNAS-IOT Home Page
Table 13: Reference Documents
5.2 Acronyms, Abbreviations, & Definitions
62
Acronym
Meaning
FTDI
Future Technology Devices
International
GUI
Graphic User Interface
IOT
Internet of Things
IVT
Instruction Vector Table
JTAG
Joint Test Action Group
MANF
Manufacturer
MCU
Microcontroller Unit
MEMS
Micro-Electro-Mechanical
System
MSD
Mass Storage Device
OEM
Original Equipment
Manufacturer
OTW
Over the Wire
OTP
One Time Programmable
ROM
Read Only Memory
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RTOS
Real-Time Operating
System
SDK
Software Development Kit
UART
Universal asynchronous
receiver-transmitter
Table 14: Abbreviations and Definitions
5.3 Revision History
Date
Version
Details of Change
Author
Reviewers
10/28/20
Production 1.1
Various Corrections
Cooper
Carnahan
NXP
9/29/20
Production 1.0
Initial Version
Cooper
Carnahan
NXP
Table 15: Revision History
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