Figure 38. SW8 DIP switch configuration with PIR sensor activated
To test the motion activated wake-up, manually set the system into sleep mode by pressing and holding the SW1 pushbutton
located on the back of the kit for >2s before releasing it. Once the board has entered sleep mode, any motion in front of the PIR
sensor will automatically wake-up the system.
6.1.3 Automatically enable low-power mode
In addition to manually activating the low-power mode setting via the onboard pushbuttons, the SLN-VIZN3D-IOT can also be
configured to automatically enter sleep mode. When automatic low-power mode is enabled, the kit uses a combination of timers
and other event triggers to determine when it is okay to enter sleep. Configuring automatic sleep mode is handled via the “lpm
enable/disable” shell command. See
Configure automatic low-power mode
While automatic sleep mode is enabled, any of the following events causes the SLN-VIZN3D-IOT to enter sleep mode:
• A face is recognized
• 10s have passed with no face detected
• 25s have passed with no recognizable face detected
However, there are states in which the above triggers will not activate low-power mode and those states include:
• A BLE connection between the kit and the Smart Lock Manager app is currently active
• A registration/deregistration is taking place
In either of the above scenarios, entering low-power mode is deferred until after the event has completed to prevent the
kit from falling asleep during processes that may take longer than the sleep timers allow for. Additionally, in the event of a
registration/deregistration, the sleep mode timers reset after the registration/de-registration is complete.
As an example of how the automatic sleep mode process might work, consider the following scenarios:
The SLN-VIZN3D-IOT is power cycled and has previously been configured with automatic sleep mode enabled. After 2 seconds
have passed with no face detected by the kit, a face is detected. After 1 more second, that face is recognized. The kit enters
sleep mode.
The SLN-VIZN3D-IOT is power cycled and has previously been configured with automatic sleep mode enabled. After 9 seconds
have passed with no face detected by the kit, an unrecognized face is detected. 10 more seconds pass with the face still
unrecognized. A connection to the Smart Lock Manager remote registration app is established. A new user is remotely registered
and the Smart Lock Manager app is closed after 30 seconds of use. As soon as the app is closed, the BLE connection between
the app and kit has been severed and the kit enters sleep mode because the 25 second “face detected” timer completed while
the remote registration app was in use.
The SLN-VIZN3D-IOT is power cycled and has previously been configured with automatic sleep mode enabled. After 9 seconds
have passed with no face detected by the kit, a face is detected. After 15 seconds, a registration is started using the SW3
NXP Semiconductors
Additional features
SLN-VIZN3D-IOT Kit User Guide, Rev. 0, 01 November 2021
User Guide
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