2. Overview

Libre Wireless, MAVID-3M module is a low power module targeted for IoT, voice/AI and audio streaming applications. The efficient low power mode states enable MAVID-3M well suitable for portable battery powered devices.

The module provides 2.4 GHz Wi-Fi connectivity, BLE 5.0, Voice Front End with 2/3 MIC Far field Voice recognition, Noise reduction and Echo cancellation.

3. MAVID–3M Features and Spec

3.1 Generic Features

  • ARM Cortex-M4 @ 192 MHz
  • Open SDK Voice/AI, IoT, Audio on Free RTOS Operating System
  • 1x UART (currently used for debugging)
  • 2x SPI (QSPI for Flash, SPI for Voice Front End)
  • 1x I2C
  • Supports up to 16 GPIO’s
  • 1x I2S Serial audio interface
  • Hi-Resolution Audio (up to 192 KHz/24 bits) stereo supported
  • LPCM, MP3, HE-AAC decode capability
  • Crypto Engine for AES 128, 192, 256. DES, 3DES, MD5, SHA-1,224,256,384,512, True Random number generator
  • Two/three Mic Far Field voice. Noise reduction (Beam Forming) and AEC
  • Up to three Digital MIC
  • Internal 4MB SRAM
  • External QSPI flash4MB (XIP)
  • 1x1, 802.11n 2.4GHz WLAN
  • BLE 5.0
  • Wi-Fi/BLE coexistence
  • Antenna diversity
  • Requires multiple voltage domains (VBAT / 3.3 V and 1.8 V)

3.2 WLAN Features

  • IEEE 802.11 b/g/n (2.4GHz, 1x1)
  • Supports 20 Mhz,40 MHz bandwidth in 2.4 GHz band.
  • Supports short GI and all data rates of 802.11n including MCS0 to MCS7
  • Wi-Fi security WEP, WPA2, WPS
  • Support Soft AP and sniffer modes
  • Supports digital pre-distortion to enhance PA performance
  • RX antenna diversity
  • Integrated 2.4 GHz PA, LNA and T/R switch
  • Single ended RFIO with integrated balun
  • Supports an optional LNA and PA
  • Dedicated high performance 32-bit RISC CPU up to 160 MHz clock to run WLAN firmware

3.3 Bluetooth Features

  • Support BLE (Bluetooth Low Energy) 5.0
  • Support BLE 1M, 2M and long range
  • Support BLE extended advertising
  • Support 8 data link connection
  • Support 128bit AES
  • Four PWM channels
  • Integrates baseband, radio for Mesh Controllers, mobile payments and wearable device applications
  • Ultra-low power consumption

3.4 Voice Front End Features

  • Dual Core DSP (Cadence Tensilica based audio centric DSP core)
  • 2/3 MIC far field voice recognition
  • Room to offload the main Application processor for dedicated tasks as per requirements
  • Can support custom Wake words and Local commands in edge as per the requirements
  • Will support digital sound processing capability for audio output path (e.g.: Equalizer, DRC)
  • Low power, low-latency, and high-performance algorithm processing at the edge
  • Xtensa HiFi 3 instruction sets enable extensive voice and audio capabilities including voice user interfacing and ambient sound processing

3.5 Platform Features

MAVID-3M comes with extensive software SDK features for Voice/AI, Audio and Multi- protocol IoT control applications. These include system level control and data transfer and bridging features as well as core networking connectivity and OTA features.

  • Below are the feature highlights for the MAVID-3M Device and please refer to the full “MAVID-3M Feature List” for details of supported features.
    • Complete Low Power AVS “Mic-to-Cloud” Solution (Amazon AVS)
    • 802.11n 1x1, BLE 5.0 complaint
    • Network configuration using BLE and WI-FI direct
    • Secure OTA Firmware Update
    • IoT Stack for AWS or custom IoT Application, Device cloud for back end support
    • Android and iOS Application for device on boarding and other functionalities
    • Self-Hosting; no external MCU required
    • Three Mic Far Field & Wake Word detection with AEC and Beamforming
    • Hardware Crypto core + OTP
    • Advanced low power state & battery management
  • 4. Block Diagram

    Figure 4-1: MAVID–3M Block Diagram

    5. MAVID-3M: Power modes and Consumption

    Table 1: MAVID-3M Device Power Consumption

    Input Voltage /Battery (v) Sub System Operating Mode Response Time Power (mW)
    3.3 Active Wi-Fi Streaming from AVS cloud. Total consumption of Wi-Fi/BLE Concurrent, Voice DSP Noise Reduction & AEC Active State Always On, Immediate 183
    3.3 Ideal Mode Wi-Fi Connected but music is not streaming Always On, Immediate 165

    6. Package Information

    Figure 6-1: MAVID–3M Module Mechanical Dimension

    Figure 6-2: MAVID-3M Module

    7. Ordering Information

    Product Number Main Processor Wi-Fi Tx/Rx Wi-Fi Bands Bluetooth only BLE Memory (Flash/RAM) Voice Dimension (L x W) ±0.2mm
    MXD31NS BKC - M Yes 802.11n 1x1 2.4 GHz BLE 5.0 4MB/ 4.4MB Yes 27 mm x 43 mm
    MXD31NSB00 - M Yes 802.11n 1x1 2.4 GHz BLE 5.0 4MB/ 4.4MB No 27 mm x 43 mm

    8. Pin Description

    Pin No. Signal Name Signal Type Description
    1 3V3 Power 3V3
    2 3V3 Power 3V3
    5 GPIO0_B Output GPO
    6 GPIO9_B Output GPO
    7 PWR_OFF Output For Power off circuit
    8 CHIP_EN Input Chip reset
    9 MIC_PWR_CTRL Output For Mic power control
    10 GND GND GND
    11 I2S_MCLK Output I2S Master Clock
    12 I2S_LRCLK Input/ Output I2S LRCLK
    13 I2S_BCLK Input/ Output I2S BCLK
    14 PORTA_RXD Input AEC reference Data
    15 I2S_TXD Output I2S data out
    16 I2S_RXD Input I2S data in
    17 I2S_PORTA_TXD Output Optional/Additional I2S data out
    18 SPI_MISO Input SPI MISO
    19 SPI_CLK Output SPI CLK
    20 SPI_CS Output SPI CS
    21 SPI_MOSI Output SPI MOSI
    22 PTT/SETUP Input/Output Button PTT / Setup
    23 MIC_PWR_ON/OFF Input/Output Button MIC / Power
    24 CHG_STATUS Input/Output For Battery charging Indication
    25 PLAY/PAUSE Input/Output Button Play / Pause
    26 DSP_GPIO0 Input/Output Knowles DSP GPIO
    27 DSP_GPIO1 Input/Output Knowles DSP GPIO
    28 DM1_CLK Output Digital MIC Data
    29 DM1_DATA Input Digital MIC Clock
    30 DM0_CLK Output Digital MIC Clock
    31 DM0_DATA Input Digital MIC Data
    32 DSP_D_UART_TX Output Knowles DSP UART TX
    33 DSP_D_UART_RX Input Knowles DSP UART RX
    34 GND GND GND
    35 UART1_TX Output UART1_TX
    36 UART1_RX Input UART1_RX
    37 GND GND GND
    38 NC NC NC
    39 1V8 Power 1.8V
    40 VDD_IO Power To connect 3V3 or 1V8 to Knowles
    41 VDD_IO Power To connect 3V3 or 1V8 to Knowles
    42 LED_RED Output AVS LED_RED
    45 RTC_EINT Input Real Time Clock External Interrupt
    46 CODEC_RST Output To enable/disable EXT CODEC
    47 GPIO8_B Output GPIO
    48 BTVBAT Power 3V3 Battery Input
    49 VRTC Power Connect 3V coin battery
    50 GND GND GND
    51 ADC1 Analog Analog
    52 I2C0_SCL Output I2C SCL
    53 I2C0_SDA Input/Output I2C SDA
    54 DEBUG_URXD Input Debug log
    55 DEBUG_UTXD Output Debug log
    56 GND GND GND