Overview:

The ESP32-LyraT V4.3 is an audio development board produced by Espressif built around ESP32. It is intended for audio applications, by providing hardware for audio processing and additional RAM on top of what is already onboard of the ESP32 chip. The specific hardware includes:

• ESP32-WROVER Module
• Audio Codec Chip
• Dual Microphones on board
• Headphone input
• 2 x 3-watt Speaker output
• Dual Auxiliary Input
• MicroSD Card slot (1 line or 4 lines)
• Six buttons (2 physical buttons and 4 touch buttons)
• JTAG header
• Integrated USB-UART Bridge Chip
• Li-ion Battery-Charge Management

Parameters:

The block diagram below presents main components of the ESP32-LyraT and interconnections between components.

ESP32-WROVER Module:

• The ESP32-WROVER module contains ESP32 chip to provide Wi-Fi / BT connectivity and data processing power as well as integrates 32 Mbit SPI flash and 32 Mbit PSRAM for flexible data storage.

Headphone Output:

• Output socket to connect headphones with a 3.5 mm stereo jack.

Left Speaker Output:

• Output socket to connect 4 ohm speaker. The pins have a standard 2.54 mm / 0.1” pitch.

Right Speaker Output:

• Output socket to connect 4 ohm speaker. The pins have a standard 2.54 mm / 0.1” pitch.

Boot/Reset Press Keys:

• Boot: holding down the Boot button and momentarily pressing the Reset button initiates the firmware upload mode. Then user can upload firmware through the serial port. Reset: pressing this button alone resets the system.

Audio Codec Chip:

• The Audio Codec Chip, ES8388, is a low power stereo audio codec with a headphone amplifier. It consists of 2-channel ADC, 2-channel DAC, microphone amplifier, headphone amplifier, digital sound effects, analog mixing and gain functions. It is interfaced with ESP32-WROVER Module over I2S and I2S buses to provide audio processing in hardware independently from the audio application.

USB-UART Port:

• Functions as the communication interface between a PC and the ESP32 WROVER module.

USB Power Port:

• Provides the power supply for the board.

Standby / Charging LEDs:

• The Standby green LED indicates that power has been applied to the Micro USB Port. The Charging red LED indicates that a battery connected to the Battery Socket is being charged.

Power Switch:

• Power on/off knob: toggling it to the left powers the board on; toggling it to the right powers the board off.

Power On LED:

• Red LED indicating that Power On Switch is turned on.

Related Documents:

• ESP32-LyraT V4.3 Hardware Reference
• ESP32 LyraT V4.3 schematic
• ESP32-LyraT V4.3 Component Layout
• ESP32 Datasheet
• ESP32-WROVER Datasheet