Espressif ESP32-LyraT Docs Template Documentation page 9

Headphone Output Output socket to connect headphones with a 3.5 mm stereo jack.
Note: The socket may be used with mobile phone headsets and is compatible with OMPT standard headsets
only. It does work with CTIA headsets. Please refer to
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 button: holding down the Boot button and momentarily pressing the Reset button to
initiate the firmware upload mode. Then you can upload firmware through the serial port. Reset button: 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.
1.1. ESP32-LyraT V4.3 Getting Started Guide
Read the Docs Template Documentation, Release
Fig. 1.2: ESP32-LyraT Block Diagram
Phone connector (audio) on Wikipedia.
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