ESP32 LyraT

ESP32-LyraTD-MSC Side View

• Low-power, low-cost lightweight smart audio solution

• Support multiple cloud platforms, DuerOS, Amazon, ESP32-lyrat aliexpress, Tmall Genie, Turing, JD.com, iFLYTEK, etc.

• Supports HTTP Living Stream, Internet Radio, Himalaya, etc.

• Support local voice interrupt wake-up, keyword recognition, echo cancellation, etc.

• Three digital MICs, support 1-5M far-field pickup

• Double board design, colorful LED light strip, full-function buttons

• Support Wi-Fi, BT, DLNA, SDCARD and other audio input

• Support Smart config, Bluetooth LE, Airkiss and other distribution networks

• Supports 2.4G band Wi-Fi 802.11b/g/n, Classic BT and Bluetooth LE

• Support multiple audio formats, such as M4A, AAC, FLAC, OGG, OPUS, MP3,AMR, etc.

Solutions for voice interaction and cloud-on-demand which are indispensable for smart speaker applications, Human-computer interaction and scene recognition required by smart AI applications, interconnection, interaction and real-time feedback required by smart home devices, etc.

Supports one-button intelligent network distribution function, supports acoustic echo cancellation (AEC), near/far-field voice wake-up, cloud platform access, voice recognition, midway interruption and audio decoding, etc., which can accelerate Bluetooth + Wi-Fi dual-mode audio Solution development process.

Dual-board audio development platform designed for smart speakers and AI applications. The upper board mainly includes hardware such as microphone array, function keys and LED indicators; the lower board mainly includes ESP32-WROVER-B Wi-Fi connection module, Micro Semi DSP chip, power management module, etc.

The main components of ESP32-LyraTD-MSC V2.2 and how they are connected:

ESP32-LyraTD-MSC V2.2 Block Diagram

ESP32-LyraTD-MSC V2.2 lower board (A) component diagram:

ESP32-LyraTD-MSC V2.2 Upper Board (B) Component Diagram

Main components	Basic introduction
ESP32-WROVER-E module	The ESP32-WROVER-E module uses the ESP32 chip for Wi-Fi/Bluetooth connection and data processing, and integrates 4 MB external SPI flash and 8 MB SPI PSRAM for flexible data storage.
DSP chip	The ZL38063 DSP chip is used for automatic speech recognition applications, which can obtain audio data from an external microphone array and output audio signals through its own DAC port.
headphone output	The output socket accepts 3.5 mm stereo headphones. This slot accepts a mobile phone headset and is only compatible with OMPT standard headsets, not with CTIA headsets. Support a variety of mainstream audio formats, including MP3, AAC, FLAC, WAV, OGG, OPUS, AMR, TS, ALC and G.711.
Two 3-watt speaker outputs on the left and right	Audio output socket with 2.00 mm / 0.08” pin spacing, recommended to connect 4 ohm 3 watt speakers.
USB-UART interface	As a communication interface between PC and ESP32-WROVER-E module
USB power supply interface	Powering the ESP32-lyratd-msc v2.2 development board
Standby/Charging Indicator	When the green Standby indicator light is on, it means that the power supply has been connected to the Micro USB port; when the red Charging indicator light is on, it means that the battery connected to the Battery port is charging.
switch	Power on/off button: Toggle the button to the right to turn on the power of the development board, and to to the left to turn off the power.
Power Indicator	The red indicator light is on to indicate that the power switch is on.
Start/Reset button	Start: Press and hold the Boot button, then press the Reset button to enter the programming mode, at this time the firmware can be uploaded through the serial port. Reset: Pressing the Reset key only resets the system.

The ESP32-WROVER-E module is a general-purpose Wi-Fi + Bluetooth + Bluetooth LE MCU module. ESP32-WROVER-E uses a PCB onboard antenna, which is powerful and versatile. It can be used in low-power sensor networks and extremely demanding High tasks such as speech encoding, audio streaming and MP3 decoding etc.

The module integrates traditional Bluetooth, low-power Bluetooth and Wi-Fi, and has a wide range of uses: Wi-Fi supports a wide range of communication connections, and also supports direct connection to the Internet through routers; Bluetooth allows users to connect to mobile phones or broadcast Bluetooth LE Beacon for easy signal detection. The chip used is ESP32-D0WD-V3 or ESP32-D0WDR2-V3* of the ESP32 series, which is scalable and self-adaptive. Two CPU cores can be controlled independently. The sleep current of the ESP32 chip is less than 5 µA, making it suitable for battery-powered wearable electronics. The module supports a data transfer rate of up to 150 Mbps and an antenna output power of 20 dBm for maximum range wireless communication. Therefore, this module has industry-leading technical specifications and excellent performance in terms of high integration, wireless transmission distance, power consumption, and network connectivity.

The application circuit diagram of the connection between the ESP32-WROVER-E module and the peripheral devices of the ESP32-LyraTD-MSC development board (such as power supply, antenna, reset button, JTAG interface, UART interface, etc.).

Illustrate:

• Pin 39 may not be soldered to the backplane. If the user solders this pin to the bottom board, please make sure to use an appropriate amount of solder paste.

• To ensure normal power supply when the chip is powered on, an RC delay circuit needs to be added to the EN pin. RC is generally recommended to be R = 10 kΩ, C = 1 µF, but the specific values ​​still need to be adjusted according to the power-on sequence of the module power supply and the power-on reset sequence of the chip. For the power-on reset timing diagram of the chip, please refer to the power management chapter in the “ESP32 Technical Specification”.

ESP32-WROVER-E Module Dimensions

This is the sub board of Micro Semi DSP development board. This Espressif ESP32 lyrat development board mainly contains LEDs display and Key-press functions, and also including Reset button and Boot button.

Before powering on the ESP32-LyraTD-MSC, please make sure that the ESP32-lyrat board ESP32-LyraTD-MSC V2.2 is intact and that the upper board (B) and the lower board (A) are tightly fastened together. Set up the board to run the first example application:

•Connect speakers to the two speaker outputs, or connect headphones to the headphone output.

•Plug in the Micro-USB cable to connect the PC to the two USB ports of the ESP32-LyraTD-MSC Espressif ESP32 lyrat.

•At this point, the green standby light should be on. If the battery is not connected, the red charge indicator flashes every few seconds.

•Toggle the power switch to the right.

•At this point, the red Power LED should be on.

If the LEDs display as above, the initial setup is complete and the ESP32-lyrat development board is ready to download applications.

The ESP32-LyraTD-MSC single board supports one-key WIFI network configuration, AEC (Acoustic Echo Cancellation), ASR (Automatic Speech Recognition), near/far-field voice wake-up and voice recognition functions. This audio IC ESP32-lyrat development board provides excellent performance characteristics with cloud platform access, fast audio decoding and wake-up interrupt. This audio IC ESP32-lyrat development board has a wide range of applications in artificial intelligence and smart speakers, including human-computer interaction and image recognition.