ESP32-LyraT-Mini V1.2 Audio Dev Board - ESP32-WROVER-E Wi-Fi/BT with ES8311 Codec

Specifications

• Core Module: ESP32-WROVER-E (Dual-core XTensa 32-bit LX6 MCU)

• Wireless: 802.11 b/g/n Wi-Fi + Bluetooth v4.2 BR/EDR and BLE

• Audio Codec: ES8311 (I2S interface)

• Audio Output: 1 x 3.5mm Stereo Jack, 1 x Speaker JST Connector

• Audio Input: 1 x Onboard Electret Microphone

• Storage: MicroSD Card Slot (SPI/1-bit SDIO interface)

• User Interface: 8 x Tactile Buttons, 1 x System LED

• Power Supply: 5V via Micro-USB or 3.7V via LiPo Battery port

Key Applications and Projects

• Smart Speakers: Building custom voice assistants that wake up to a specific trigger word and query cloud services via Wi-Fi.

• Internet Radio Receivers: Streaming global web radio stations and decoding the audio streams in real-time.

• Two-Way Walkie-Talkies: Creating a Wi-Fi-based intercom system using the onboard microphone and speaker outputs.

• Audio Storyboxes: Designing interactive, battery-powered toys that play specific MP3s from the SD card when buttons are pressed.

Unlock New Capabilities (Project Evolution)

• Software Ecosystem: While you can program this via the Arduino IDE, the true power of this board is unlocked by using the Espressif Audio Development Framework (ESP-ADF). ESP-ADF provides extensive, optimized libraries for audio streaming, decoding (MP3, AAC, FLAC, WAV), and voice recognition!

Downloads and Links:

• ESP32-WROVER-E_Datasheet
• ESP32-LyraT-Mini V1.2 _Schematic
• ESP32-LyraT-Mini V1.2 Getting Started Guide_Github

Package Includes:

• 1 x ESP32-LyraT-Mini V1.2 Audio Development Board (Note: Rubber standoff feet are pre-installed on the bottom of the PCB)
  

FREQUENTLY ASKED QUESTIONS (FAQ)

1. What is the ESP32-LyraT-Mini? It is an official audio-focused development board made by Espressif, designed to help engineers easily prototype Wi-Fi/Bluetooth speakers, internet radios, and voice-recognition devices.

2. What module runs this board? It uses the ESP32-WROVER-E module, which includes Wi-Fi, Bluetooth, and built-in PSRAM.

3. Why is PSRAM important for audio? Processing audio (especially decoding MP3s or buffering internet radio streams) requires a lot of RAM. The extra PSRAM inside the WROVER module prevents the audio from stuttering.

4. What audio codec does it use? It uses the ES8311, a highly efficient, low-power mono audio codec designed specifically for IoT devices.

5. Does it have a microphone? Yes, there is a small cylindrical electret microphone pre-soldered to the bottom left of the board, labeled "MIC".

6. How do I listen to the audio? You can plug standard headphones into the black 3.5mm "AUDIO_OUT" jack, or you can plug a small bare speaker into the white "SPEAKER" JST connector.

7. Why are there two Micro-USB ports? The top port ("UART") connects to the USB-to-Serial chip for programming the board and viewing debugging logs on your PC. The middle port ("POWER") is used purely to provide 5V power to the board.

8. Can I run this on battery power? Yes! There is a white 2-pin JST connector labeled "BAT" on the right side for connecting a standard 3.7V Lithium-Polymer (LiPo) battery.

9. Will it charge my battery? Yes, when you have a battery plugged into the "BAT" port and a USB cable plugged into "POWER", the board will safely charge the LiPo battery.

10. What is the silver slot at the bottom? That is a MicroSD card reader. You can use it to store local MP3/WAV files for playback, or to record audio data from the microphone.

11. What do all the buttons do? The row of buttons (Vol+, Vol-, Sel, Play, Mode, Rec) are wired to the ESP32's GPIO pins, allowing you to easily program physical controls for your media player without adding external components.

12. What are the Boot and RST buttons? "RST" hard-resets the ESP32. "Boot" puts the ESP32 into programming mode (though the onboard USB-to-Serial chip usually handles this automatically).

13. Is there an ON/OFF switch? Yes, there is a physical sliding "POWER SWITCH" located near the center of the board to easily power down your project.

14. What framework should I use to program this? While basic functions work in the Arduino IDE, it is highly recommended to use the official ESP-ADF (Espressif Audio Development Framework) within the ESP-IDF environment for full audio streaming and DSP support.

15. Does it support Bluetooth Audio? Yes, the ESP32 supports A2DP (Advanced Audio Distribution Profile), allowing you to program the board to act as a Bluetooth speaker receiver or a Bluetooth transmitter.

16. What are the white circles on the back of the board? Those are four rubber standoff feet that prevent the metal solder joints on the bottom of the PCB from shorting out against your desk.

17. Can it do voice wake-up (like "Alexa")? Yes, using the ESP-ADF software, you can run wake-word engine (WWE) algorithms to trigger actions based on specific spoken phrases.

18. Are there extra pins I can use for my own sensors? The LyraT-Mini is highly integrated, so many of the ESP32's pins are used by the codec, SD card, and buttons. However, there are some through-hole test points (like the JTAG header) that expose certain GPIOs.

19. What is the large silver cylinder on the board? That is a 220uF 16V electrolytic capacitor, used to smooth out the power supply and prevent electrical noise from causing static in your audio signal.

20. Is the board strictly mono or stereo? The ES8311 codec is technically a mono codec. While the 3.5mm jack will output sound to both the left and right ears of your headphones, it will be the identical mono signal, not true distinct stereo separation.