Listening and Talking WisBlock Audio Modules for IoT

We are excited to launch a new series of WisBlock modules – WisBlock Audio!

Previously when it came to audio, we had the RAK18001 Buzzer Module and the RAK18000 Stereo Microphone Module. We are now enhancing these audio modules by adding a full series of modules: microphone modules, amplifier modules, an audio processing module, and an interposer module. The modules are supported by a set of audio accessories to ensure that a full end product can be built with minimal (if any) other parts. To make it easier, we have created a number of WisBlock Audio Kits which include all the modules and accessories you will need for your application.

WisBlock Audio enables professional IoT audio solutions

• Compact plug and play solution
• A broad selection of example code
• A number of different microphones
• Speaker Amplifiers
• Verified Audio Enclosures
• DSP base Voice Processing
• A choice of three different processing cores

Sample WisBlock IoT audio solutions:

Table of Content

• WisBlock Audio Modules
• PDM Microphone Modules
• Analog Microphone Module
• Amplifier Modules
• Audio Processing Module
• Interposer Module
• Speech Recognition
• WisBlock Audio Kits
• WisBlock Microphone Interposer Kit
• WisBlock Speaker Amplifier SD Kit
• Remote Microphone Kit
• Stereo Microphone Kit
• Amplifier Microphone & SD Kit
• WisBlock Voice Processing Kit
• WisBlock Voice Processing Speaker Kit
• WisBlock Audio Accessories
• Speaker Wire
• Amplifier Wire
• PDM Microphone FFC
• M8 Power Connector
• Speaker
• WisBlock Audio Spacer Kit
• WisBlock Audio Enclosure

WisBlock Audio Modules

Here's a list of all the WisBlock Audio Modules. These modules can be purchased on their own (unless noted).  If you are purchasing multiple WisBlock Audio modules, one of the kits below is a much better option as it includes all the correct accessories needed to build the full WisBlock Audio system (and will be cheaper ☺).

If you want to jump directly to a module type here are the quick links:

• WisBlock Audio Microphone modules
• PDM Microphone Modules
• Analog Microphone Modules
• WisBlock Audio Amplifier modules
• WisBlock Audio Audio processing module
• WisBlock Audio Interposer module.
• This is the “glue” to connect multiple WisBlock Audio modules onto a WisBase IO slot
• WisBlock Audio Accessories
• WisBlock Audio Kits
• Includes all the boards and accessories you will need for a number of applications

PDM Microphone Modules

We are launching three new PDM microphone modules. All three modules have the microphone on the module and have the same pinouts on the WisBlock IO and FPC connectors. The audio signal is converted to the PDM protocol and is passed to the WisCore. The modules also have a GPIO signal from the WisCore to change the output to be the Left or Right audio channel and a detect signal to know when the module is plugged in.

Common PDM Microphone Module Features:

• PDM microphone
• Omnidirectional sensitivity
• Size 15mmx 25mm

Notes:

1. The only microphone module supported when using the RAK18080 - DSPg DBM10L is the RAK18030
2. The current RAK18000 will be sold until stock runs out. The replacement microphone module is the RAK18031 which uses the same microphone but is mono. If stereo is needed then the RAK18033 (see below) can be used.

RAK18033 Stereo PDM Microphone Header

The RAK18033 is a breakout module that allows you to connect up to two RAK PDM microphone modules onto a WisBlock Audio Interposer module or a WisBlock Base board. This allows you to have stereo audio for your WisBlock system.

RAK18033 Stereo PDM Microphone Header Module Features:

• Up to two RAK Wireless PDM microphones
• Secure FPC cable connections
• WisBlock IO or WisBlock Audio Interposer compatible
• Size 15mmx 25mm

Analog Microphone Module

If you would like to use a more specialized microphone you can choose your own analog microphone and convert it to I2S using the RAK18040 connected to any of the WisBlock Cores.

RAK18040 Analog Microphone to I2S Module

The RAK18040 is a stereo analog microphone to I2S module based on the Nuvoton NAU85L40B Audio ADC. The RAK18040 allows a user to connect up to two analog microphones into a WisBlock System.

RAK18040 Analog Microphone to I2S Module Features:

• Samples rates from 8 kHz to 96 kHz at 24bit resolution
• 92 dB THD+N
• 101 dB(A) signal-to-noise ratio
• I2C control interface
• Size 15mmx 25mm

Amplifier Modules

We are launching two amplifier modules: a mono amplifier module and a stereo amplifier module. Both modules are based on the 5.6W Texas Instruments TAS2560 chip.

Common Amplifier Module Features:

• I2S interface for audio data
• I2C interface for control
• 5.6 W at 1% THD*N into 4 Ohm Load from a 4.2V supply
• High-Efficiency Class-H Boost Converter
• Built-in Speaker Sense and Automatic Gain Control
• Thermal. Short-Circuit, and Under-voltage Protection
• Size 25mmx 35mm

Audio Processing Module

We are launching the first audio processing module, a voice processing module using the Synaptics/DSPg DBM10L chip. This DSP chip provides the capability to run speech recognition software from a leading embedded speech solution provider. RAK will be providing example voice models to evaluate the solution. For larger customers, RAK can create new models (different trigger words and commands) for a fee.

Note: Voice recognition can also be done directly on a WisCore – see Speech Recognition.

RAK18080 Module Features:

• I2S interface for speaker audio data
• PDM interface for microphone audio data
• I2C interface for control
• Embedded DSP for audio processing
• Size 25mmx 35mm

Note: This module is not available for purchase alone, it much be purchased in a kit (see WisBlock Voice Processing Kit and the WisBlock Voice Processing Speaker Kit below)

Interposer Module

If more than one WisBlock Audio module is used, then an Interposer module is needed. RAK is launching the first interposer module in this Launch. The RAK18003 Audio interposer module allows a full set of WisBlock Audio modules (DSP, Amp, Microphone) to be stacked together using a single WisBlock IO slot. The Interposer module also allows for the PDM microphone module to be located away from the stack (eg connected to a case).

A MicroSD slot is supplied for the storage of configuration or logging data.

Note: audio cannot be streamed to or from the SD card as the interface is too slow (This will be resolved in our next launch ☺)

RAK18003 Module Features:

• Extend IO for Wiscore to control other modules
• FPC connector for connecting PDM microphone modules
• TF-card connector
• Board to Board (BTB) connector for WisBlock Audio module stacking
• Size 25mmx 35mm

Note: This module is not available for purchase alone, it can only be purchased in a kit (see WisBlock Audio Kits below)

Speech Recognition

To complement the RAK18080 module, we are also launching a software-only solution for speech recognition. You can purchase a WisCore module that is licensed to run speech recognition software from a leading embedded speech solution provider, or you can follow our guides to run Edge Impulse Machine learning software. For more information, please see our page on Speech Recognition.

WisBlock Audio Kits

If you are planning on purchasing multiple WisBlock Audio modules, one of the kits below is a great way to get all the accessories for a full solution without any confusion!  Each kit includes all the correct accessories needed to build the full WisBlock Audio system (and is cheaper than buying them separately).

WisBlock Microphone Interposer Kit

The WisBlock Microphone Interposer Kit allows you to use a microphone in your WisBlock system and mount it away from the base board (if desired), and also has an SD card for configuration or logging. (Note you cannot save the audio to the SD card on the RAK18003 (this feature will be available on a future interposer module)).

The WisBlock Microphone Interposer Kit includes a microphone of your choice along with the RAK18003 WisBlock Audio Interposer. The kit also includes all the accessories needed to connect the module electrically and mechanically.

The WisBlock Voice Processing Kit includes:

• An Audio Interposer module (RAK18003) to stack all the modules on a single IO slot
• A Microphone module – one of:
• RAK18030 (20-20kHz PDM Microphone)
• RAK18031 (20-10kHz PDM Microphone)
• RAK18032 (20-80 kHz PDM Microphone)
• An optional custom audio case to put it in
• All the screws and cables needed to stack the modules together

Note: This kit does not include a base board or WisCore.

WisBlock Speaker Amplifier SD Kit

The WisBlock Speaker Amplifier SD Kit allows you to use a speaker in your WisBlock system and also has an SD card for configuration or logging. (Note you cannot play audio from the SD card on the RAK18003 (this feature will be available on a later interposer module).

The WisBlock Speaker Amplifier SD Kit includes an amplifier of the users’ choice along with the RAK18003 WisBlock Audio Interposer. The kit also includes all the accessories needed to connect the modules electrically and mechanically together.

The WisBlock Voice Processing Kit includes:

• A RAK18003 Audio Interposer (with SD card slot)
• RAK18060 or RAK18061 5.6W Amplifier module (Mono/Stereo)
• Optional Speakers
• All the Screws and cables needed to stack the modules together
• An Optional Enclosure to put everything in

Note: This kit does not include a base board or WisCore.

Remote Microphone Kit

The WisBlock Remote Microphone Kit allows you to use a PDM microphone module in your WisBlock Audio system while mounting the microphones away from the base board.

The kit also includes all the accessories needed to connect the modules electrically and mechanically together.

The WisBlock Remote Kit includes:

• A RAK18033 Stereo PDM Microphone Header module
• A PDM Microphone module of your choice
• All the Screws and cables needed to stack the modules together
• An Optional Enclosure to put everything in

Note: You will also need to purchase a base board and WisCore.

Stereo Microphone Kit

The WisBlock Stereo Microphone Kit allows you to use two PDM microphone modules (stereo) in your WisBlock Audio system. It also provides the ability to mount the microphones away from the base board and separately from each other.

The kit also includes all the accessories needed to connect the modules electrically and mechanically together.

The WisBlock Voice Processing Kit includes:

• A RAK18033 Stereo PDM Microphone Header module
• A PDM Microphone module of your choice
• All the Screws and cables needed to stack the modules together

Note: You will also need to purchase a base board and WisCore.

Amplifier Microphone & SD Kit

The WisBlock Amplifier Microphone SD Kit allows you to use a speaker and microphone in your WisBlock system and also be able to have an SD card for configuration or logging. (Note you cannot play audio from the SD card on the RAK18003 (this feature will be available on a later interposer module))

The WisBlock Amplifier Microphone SD Kit includes a PDM microphone of your choice, an amplifier of your choice along with the RAK18003 WisBlock Audio Interposer. The kit also includes all the accessories needed to connect the modules electrically and mechanically together.

The WisBlock Voice Processing Kit includes:

• A RAK18003 Audio Interposer (with SD card slot)
• RAK18060 or RAK18061 5.6W Amplifier module (Mono/Stereo)
• RAK18030, RAK18031, or RAK18032 PDM microphone module
• Optional Speakers
• All the Screws and cables needed to stack the modules together
• An Optional Enclosure to put everything in

Note: You will also need to purchase a base board and WisCore.
Note: You cannot playback or record audio directly from the SD card, it can be used for logging or configuration.

WisBlock Voice Processing Kit

The WisBlock Voice Process Kit is the first of two kits designed for voice control. The PDM microphone module listens while the DSP module performs analysis on the audio to determine if trigger words or commands have been said. (This is done with our partner software running on the DSP chip)

The kit includes all the accessories needed to connect the modules electrically and mechanically together.

Notes:

• This kit will also be able to be used for sound recognition (eg glass break) in the future when the firmware is available.
• The Custom case must be used (the audio has been tuned to work with the case)
• RAK will not support users not using the case!

The WisBlock Voice Processing Kit includes:

• An Audio Interposer module (RAK18003) to stack all the modules on a single IO slot
• A RAK18030 PDM Microphone module
• A RAK18080 DSP module for the audio processing
• A custom audio case to put it in
• All the Screws and cables needed to stack the modules together

Note: You will also need to purchase a base board and WisCore.

WisBlock Voice Processing Speaker Kit

The WisBlock Voice Process Speaker Kit is the second of two kits designed for voice control. This kit is the same as the first but includes a speaker for audio responses (to acknowledge a trigger for example).

The PDM microphone module listens while the DSP module performs analysis on the audio to determine if trigger words or commands have been said. (This is done with our partner software running on the DSP chip)
The kit includes all the accessories needed to connect the modules electrically and mechanically together.

Notes:

• This kit will also be able to be used for sound recognition (eg glass break) in the future when the firmware is available.
• The Custom case must be used (the audio has been tuned to work with the case)
• RAK will not support users not using the case!

The WisBlock Voice Processing Kit includes:

• An Audio Interposer module (RAK18003) to stack all the modules on a single IO slot
• A RAK18030 PDM Microphone module
• A RAK18060 or RAK18061 amplifier module
• A RAK18080 DSP module for audio processing
• A custom audio case to put it in
• All the Screws and cables needed to stack the modules together

Note: You will also need to purchase a base board and WisCore.

WisBlock Audio Accessories

In order for you to have a full product solution a number of WisBlock Audio accessories are also being launched. All of the kits include all the accessories needed; however, you can also purchase the accessories separately if needed.

Speaker Wire

The Speaker Connector Cable is suitable to connect your speaker to the speaker connector of your RAK18060 or RAK18061 module.
Length 200 mm

Amplifier Wire

The Amplifier Connector Cable is suitable to connect your power source to the power connector of your RAK18060 or RAK18061 module.

Length 200 mm

PDM Microphone FFC

The PDM Microphone FPC is used to connect your RAK PDM Microphone module to a WisBlock Audio Interposer module, or the Stereo Microphone Header module.

Lengths available:

• 50 mm
• 120 mm

M8 Power Connector

The M8 Power Connector provides a waterproof connection into your WisBlock Enclosure. It is available in a number of options:

1. M8 --> Amp module Power (2 wires) - Wire Lengths 120mm
• 3 of the signals are not connected
2. M8 --> Amp module Power (2 wires) + 3 bare wires – Wire lengths 120mm
3. M8 --> Amp module Power (2 wires) + Solar connector - Wire length 120mm
• Solar connector is for power to base board
4. M8 --> Solar connector + 3 bare wires
• Solar connector is for power to base board – Wire length 120mm
• Bare wires can be used for GPIO or other functions – Wire length 200mm

Speaker

If you are not using the WisBlock Audio Enclosure, you may purchase a speaker from RAK to use with the RAK18060/18061

• 3W
• 93 dB SPL
• 70x31x17.5mm

WisBlock Audio Spacer Kit

If you are using multiple WisBlock Audio modules, these spacers allow you to mechanically join the modules together into a robust stack.

WisBlock Audio Enclosure

To allow you to create a full final product RAK is launching the WisBlock Audio Enclosures for your WisBlock Audio system. The WisBlock Audio enclosure is the standard RAK 100x75x38mm enclosure with cut-out and accessories to complement the WisBlock Audio modules.

Note: The Enclosures are provided as options when buying a WisBlock Audio kit.

Base Options:

• Without any cut-outs (standard base)
• With an M8 power connector cut-out
• With a hole for an SMA (for LoRa Antenna) cut-out
• With both an M8 power connector and SMA cut-out

Lid Options

• A Microphone cut-out (for a RAK1803x PDM microphone)
• Includes all gaskets and screws
• A Speaker cut-out
• Includes speaker, all gaskets, and screws
• Both a Microphone and Speaker cut-out