Plug It In
The SLN-ALEXA-IOT Kit arrives in a box as shown below. Inside the box, in addition to
the kit, you will
find a Quick Start Card, “Let’s Get Started!,” and a USB Type-C to dual Type-A
cable, as shown in Figure
1. The kit is pre-programmed with an audio playback control demo that is ready to run, as soon as it is
powered via the USB cable.
1.2 Package and Collateral Content
The owners of the SLN-ALEXA-IOT development kit may have a “Let’s Get Started card” in the box. This is
no longer needed so please disregard.
1.3 Power On
Plug the USB Type-C connector into the SLN-ALEXA-IOT Development kit and the dual Type-A connectors into
When you power on the kit for the first time, you will see the LED cycle through various color patterns.
These are status indicators for the various stages of the boot process as the chip cycles from internal
ROM, to bootstrap, to bootloader and finally to the running the application. When the device has booted,
the LED will turn from red to orange to indicate it’s ready to onboard.
The SLN-ALEXA-IOT Development kit starts in Wi-Fi access point mode which will be displayed on any
device that has Wi-Fi client available. The SSID will be “MCU_Voice_” followed by the
Development kit’s serial number.
The password of this Access Point is the serial number of the device.
Use the phone Wi-Fi network to connect to the device using these settings:
- SSID: MCU_Voice_<board_serial_number>;
- Password: <board_serial_number>
- .g. SSID: MCU_Voice_Rin4ZdJBFhM=, password: Rin4ZdJBFhM=.
To start onboarding, search and install the “NXP Voice Companion Application” in the iOS or Android
After downloading the application, you are ready to start communicating with the SLN-ALEXA-IOT
development kit. Connect to the Wi-FI Access point on the mobile phone.
1.4 Connecting to Wi-Fi
Once connected, open the NXP Voice Companion App and select “WIFI PROVISION”. If the
device is not connected to the SLN-ALEXA-IOT Development Kits Wi-Fi, a prompt is shown.
When the SLN-ALEXA-IOT Development kit is discovered, it will list the available Wi-Fi access points the
SLN-ALEXA-IOT Development kit can join.
Select one of the available Wi-Fi networks from the list and provide the password
associated with the
Wi-Fi SSID. Once the password is correctly entered, press the “SEND” button to
transmit the Wi-Fi
credentials to the SLN-ALEXA-IOT Development kit or select “CANCEL” button
to make another selection.
Once the credentials have been sent, the application will inform the user to join the mobile
same Wi-Fi network that was sent to the SLN-ALEXA-IOT Development kit. Having both devices using the
same Wi-Fi network is mandatory for the onboarding process.
Within the prompt, select the “GO TO SETTINGS” button, which will open
the Wi-Fi settings page. Connect
to the Wi-Fi network which was sent to the SLN-ALEXA-IOT Development kit.
When returning to the application, it will verify the Wi-Fi network that was joined on the
is the same as the one sent to the SLN-ALEXA-IOT Development kit.
If the Wi-Fi network is not the same the application will ask to join the correct network
If the Wi-Fi network is the same, the application will redirect to the
“Discover” listing screen.
1.5 Onboarding to Alexa
The device should be in the discovery mode state showing a blue LED (D2). When the
"Discover" screen is
shown (either automatically or by being selected on the main screen), it will discover all SLN-ALEXA-IOT
Development kits and display the serial number in the list.
If no SLN-ALEXA-IOT Development kits are found on the same network, a “No Devices
Found” message will
appear in the NXP Voice Companion App.
To start the onboarding of the SLN-ALEXA-IOT Development kit to your Amazon Alexa account, select the
device you wish to onboard. This will start the Login with Amazon (LWA) process.
NOTE: In the case that you already have the Amazon Shopping application, it will flash with LWA page and
automatically associate with the account logged into the Amazon Shopping application.
Once the credentials have been entered and a successful logged in, the NXP Voice Companion App will
continue to communicate with the SLN-ALEXA-IOT Development kit and display a completion percentage.
When the Access Token from LWA has been received, the SLN-ALEXA-IOT Developent kit will begin to connect
to the cloud and register with the “AVS on MCU” service, which will turn the LED (D2)
orange while this
If the device fails to register, the NXP Voice Companion App will display an “failed to
underneath the serial number in the list.
Once the device has completed the LWA process, the NXP Voice Companion App will update the percentage.
The device will start blinking green every 500ms until the device has successfully connected to AWS IoT
Once the device has successfully connected to AWS IoT Core, it will commence the registration and
connection to AVS via AWS IoT which results in the device blinking green every 250ms.
Once the device has completed, the serial number in the NXP Voice Companion App will change to yellow
with the text being shown as “complete” while the SLN-ALEXA-IOT Development kit turns the LED (D2) off
and plays a chime.
The SLN-ALEXA-IOT Development kit is now connected to your Amazon Alexa account. If you go into the
Amazon Alexa application, the kit should be listed in your devices and called “NXP-Voice-Solution”.
1.6 Interacting with Alexa
The first indication that the device is listening is when the Alexa wake word is uttered. When the
SLN-ALEXA-IOT Development kit detects the wake word, a cyan light will be shown, it will start to listen
and send microphone data to AVS via AWS IoT.
After the device has finished sending microphone data to AVS via AWS IoT, the device will stop listening
and go into thinking state. This state indicates that the AVS is processing the request and is trying to
give the best response. While in this state, the devices LED (D2) will blink cyan and blue every 200ms.
After the device has finished thinking, it will start to respond. Before the speaker outputs audio, the
LED (D2) will go into the “speaking” state which is shown by blinking cyan and blue
While the LED (D2) is blinking, the response from Alexa will start playing out of the speaker. The
response should indicate the weather conditions based on the location of your Alexa consumer account.
Once this has completed, the LED (D2) will stop blinking and turn off to indicate it is now in an idle
state waiting for the “Alexa” wake word.
4.1 Mass Storage Device (MSD) Update
The MSD feature allows the device to be updated without the Segger tool and instead, via USB. Only the
“ais_demo” can be updated while the bootloader and bootstrap remain the same. If the
bootloader need updating, this will have to be done via Segger or the Factory Programming flow.
The MSD feature by default bypasses signature verification to allow an easier development flow as
signing images can be a process not suitable for quick debugging and validation.
PLEASE NOTE, BYPASSING IMAGE VERIFICATION IS A SECURITY HOLE AND IT IS THE
RESPONSIBILITY OF THE PRODUCT MAKER TO REMOVE THE VIOLATION.
To put the device into MSD mode, hold down switch 2 (SW2) and power cycle the board until the purple LED
(D1) blinks on and off in three second cycles.
After observing the LED behavior, navigate to “My Computer” and confirm that the SLN-ALEXA-IOT kit has
mounted as a Mass Storage Device
Take the compiled “ais_demo” binary and drag the file into the MSD. This will start the download process
and write the binary to flash.
After the image has been programmed into flash, the image that has been loaded will begin to execute.
Validate this by checking the version of the image compiled, matches the version in the console by
If the image is compiled to run in the wrong application bank, an error will occur. The developer will
be required to recompile the application to the bank the device is not running from.
PLEASE NOTE, THIS REQUIRES AN AIS_DEMO BINARY THAT HAS BEEN COMPILED TO RUN IN THE
OPPOSITE BANK THE CURRENT APPLICATION IS RUNNING IN
4.2 Connect a Serial Terminal
Connect a serial terminal application to the USB serial device interface that enumerates (115200-8-N-1).
Is a snapshot of serial terminal setup.
Press Enter on the keyboard and you will see the SHELL>> prompt. Type
help to show the available
commands. Shows the available commands, with a description of each.
To obtain the logs of the SLN-ALEXA-IOT kit, type “logs” in the serial console.
4.3 Changing the Wi-Fi via Serial Terminal
To connect to a Wi-Fi Access Point, type “setup <SSID> <Password>” and press enter. In the
case of unusual characters, wrap the values in quotes (“”).
4.4 Obtain the Serial Number via Serial Terminal
Some situations require access to the serial number for onboarding or other scenarios. To obtain this,
in the serial console, type “serial_number” which will output the serial number of the SLN-ALEXA-IOT
4.5 Migrate to your own AWS IoT
The SLN-ALEXA-IOT kit by default connects to an NXP Semiconductor AWS Server by default to show how
consumers would use out of the box. To migrate it to a developers account, navigate to the
SLN-ALEXA-IOT-MG guide which details the process.